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12V batteries and battery boxes

see also:

  • I don't sell any of these nor do I receive any remuneration if you buy them, and I have not personally reviewed all of them, they are listed here to give you perspective
  • this page gives details and examples of deep cycle batteries which allow greater capacity to be used BUT they cannot be used to jump start your vehicle - see lithium jump start batteries and other jump starters for this use
  • new battery technologies are likely to come by 2027-2030 which will be much better than lithium so don't invest too much money
  • you cannot charge these up at electric vehicle charging stations!
    • you might be able to charge these from your EV with a 240V adapter and your usual 240V AC charger
  • most of these are NOT designed to be used in the engine bay - it is too hot there!
  • if mounting them under your vehicle make sure they are protected from puncture and they are fully waterproof - see https://www.youtube.com/watch?v=KkK0hEDKNzs

Introduction

  • the main 12V battery in a car is usually ~48Ah capacity but is able to generate a brief high current of 400A or more (“cold cranking amps”) to start the car engine
    • these are lead acid batteries and do not like running below 50% capacity as this not only will likely fail to crank the car but will damage the battery
    • the nominal full charge is ~12.6V, if its voltage falls below 11.8V (which usually equates to ~50% discharge), starting becomes difficult, and below roughly 10.8 to 11.5 V, the battery will likely fail to crank the engine effectively
  • an auxiliary deep cycle 12V battery of around 100Ah (1280Wh) is a great addition for your camping trip
    • these deep cycle batteries can be safely depleted to much more than 50% depletion, but their maximal current outputs are generally only 100-200A and NOT high enough to start your car
  • your best option is probably a LiFePO4 battery (see below for advantages over a traditional lead acid battery)
  • even without an offgrid charging system (solar or DC-DC from your car alternator), a reasonable size battery of 100AH will power most of your devices and even a car fridge for a few days with care, and without need for recharge.
  • for those on longer trips, an off-grid power re-charge will be needed
  • most 12V batteries come in a sealed maintenance free box with two terminals
  • many 12V batteries can be connected in parallel with similar capacity and chemistry batteries to create larger capacity
  • some 12V batteries can be connected in series to create 24V or 48V systems
  • while you could connect alligator clamps or M8 terminals to these and then to a cable with 50A Anderson plugs and an inline fuse to run your devices (there are lots of converter cables for Anderson plugs such as cigarette lighter, etc), a safer option is for either:
    • install in a battery box
      • these provides added protection to the battery while minimising risks of short circuits of the terminals
      • they generally have a variety of output ports such as Anderson plugs (these can be used for charging the battery too), 10A cigarette lighter female sockets, USB out ports
      • they usually also have a voltmeter to help you roughly estimate how much capacity is left in the battery (a more accurate method requires installing a special capacity meter with a shunt wired to the battery)
      • lastly they have a On/Off switch to disconnect the battery from the ports
      • you will need to also buy a 240V AC-DC charger (preferably a 25A lithium charger - see below)
    • purchase an all in one “Power Station”
      • this has a fixed battery, ports, charger and often an AC inverter in the one fixture for convenience
      • the downsides are:
        • unable to replace the battery
        • are expensive for what they are - generally have lower capacity eg. 50Ah unless you pay over $1000
        • generally slow re-charge times (often only 5A)
        • don't have Anderson plugs
        • are very restricted in power outputs for DC devices (usually limited to 126W)
        • most people don't really need AC outputs at camps
          • most laptops now can run off USB-C power, or at least could be recharged by USB-C as can many cameras
          • most AC powered heating or cooking options use far too much power for many of these power stations
      • see 12V DC and 240V AC output power stations

Summary recommendations

  • option 1: if you need high wattage output for a 2000W AC Inverter:
    • you need a high quality 200-300Ah LiFePO4 battery with a maximum continuous discharge rate of at least 200A as this will allow high wattage power usage (a 100Ah battery will max out at 100A or 1150W)
    • this will allow relatively short usage of induction stoves and similar devices
    • if you will be running a high wattage device for a long period such as a caravan air conditioner, you will also need a high wattage charging such as a petrol generator
  • option 2: the Power Station option - if you are not really a camper and not really an off-roader, but have plenty of spare money and value convenience
    • consider an all-in-one Power Station for convenience (~AU1000-2000 for a 100Ah one, or $AU600 for a 40Ah one)
      • great for 1-3 nights of camping (may power a fridge for 24hrs if 60Ah), or longer camps in conjunction with a solar panel to slowly recharge
      • BUT BEWARE:
        • very few have Anderson plugs - and these are incredibly useful for campers
        • the absence of Anderson plugs means:
          • the maximum DC output is usually restricted to only around 126W (and that is via a 12V cigarette plug)
          • you can't add in a remote Anderson plug power control box for 100W USC-C PD, etc
          • there is increased risk of your fridge becoming disconnected en route as cigarette plugs have a habit of losing connection while driving, especially on corrugated roads - Anderson plugs do not have this issue
        • the “attractiveness” of having built-in AC inverters is often a bit of a false one as:
          • many have relatively small capacity batteries and an AC device of 1200W or higher will rapidly deplete the battery (a 1200W device will deplete a 60Ah 12V power station in about half an hour of use) - and many have relatively slow re-charge rates even from AC power
          • it is often more efficient to have 12V camping devices rather than the more dangerous 240V AC products but these will not power a 12V product greater than 126W
          • they usually do not have earth-leakage RCD safety switch mechanisms for the 240V loads which increases risk of electric shocks especially if devices are used in a camping environment
        • many are old tech - they do not last as long as Option 3 as most are not LiFePO4 but older lithium style, charge much slower and have lower maximum power outputs
        • if a part fail the whole unit may become useless - make sure there is a 5yr warranty
        • they are more attractive to thieves
      • eg. EcoFlow RIVER 2 Pro Portable Power Station $AU1099 60Ah 3000 cycle LiFePO4 battery, 70min full recharge on AC, 7.8kg, A/C (870W), cig lighter (100W), solar (max 220W) or up to in/out 100W USB-C charging; IP68 weatherproof; pure sine wave 800W (1600W with X-boost surge mode) AC inverter built-in; 126W DC 12V output; Bluetooth smartphone app;
        • for comparison, option 4 (below) with 100Ah battery, battery box, and AC charger will cost about the some amount and no AC inverter or USB-C and lacks the convenient less confusing weatherproof package but you get Anderson plugs as well and almost twice as much battery capacity (may get more than 3 days fridge power) and the charger can be used for other batteries and left at home for the trip, and can be set up with a faster 240W or more DC-DC charger to be powered while you drive
  • option 3: if you are on a budget or think your battery may get stolen, or you only have a short camp durations
    • consider a budget cheap LiFePO4 60-100Ah battery and a cheap battery box plus a 15A or 25A lithium AC-DC charger
    • BUT CHECK they are reasonable quality with ratings of around 2000-4000 cycles of 80% discharge (DoD) otherwise they may not last long
  • option 4: otherwise, for best reliability, versatility and fastest recharge times:
    • get a high quality 100Ah LiFePO4 battery and a 25A lithium AC-DC charger such as a Victron BlueSmart IP65 12V 25A (~$AU300) so you don't waste hours recharging at a camp ground, plus add in a battery box of your choice
    • consider adding a 40A DC-DC charger (eg. Victron) so it can be rapidly charged from your car alternator (requires cabling) while driving, or from a solar panel
    • NB. unless you are going off-grid for more than 6-7 days, you probably would be better suited to having an extra 100Ah battery (total 200Ah) rather than having the hassle, cost and unreliability of using solar panels - rain, wind and cloud will not serve you well (unless you are using a 2000W AC inverter, 2 x 100Ah batteries are generally better than 1 x 200Ah battery as the weight and size of each battery is more manageable, will fit in standard battery boxes, and you have a back up if battery fails or goes flat because you accidentally left something turned on)

Physical size considerations

  • battery size in volume terms is generally in proportion to the Ah capacity
  • rear seat floor of a car:
    • 48cm wide x 20cm deep (but could be deeper if move front seat forwards) - measure your own car
    • generally fits a compact 100Ah standard size battery box or a compact high density 200Ah or 300Ah LiFePO4 battery without a battery box
  • height of hide in a Subaru Outback boot = 41cm
  • wall mounting on RV's or 4WDs:
    • consider slimline models
  • standard battery boxes are generally designed for sizes consistent with 80-120Ah batteries
    • larger batteries will not fit in a standard battery box so you will need to strap them down and you will need an Anderson power control box such as:
      • Anderson plug Power Control Box - 4x Anderson plugs, 2xcigs, 100W USB-C PD 20W USB-C PD, 2x USB QC, 2x 10W USB-A, 2x 12V DC, LED light; meter, thermometer; 166x58x116mm; Aliexpress $109
    • smaller batteries may require additional spacers to avoid movement of battery within the box or a smaller box

12V battery sizes

  • standard 12V battery boxes fit Group 24/27/29/31 batteries, with internal dimensions around 330mm L x 180mm W x 220-240mm H
  • Group 4D batteries measure approximately 20.75 inches (527mm) L x 8.75 inches (222mm) W x 9.88 inches (251mm) - generally for RV or marine use
    • Group 4D battery boxes are generally 21.2“ x 11.1” x 9.6“ H
    • a 25kg 300Ah LiFePO4 battery can be found at 15.12 x 7.64 x 9.96 in / 384 x 194 x 253 mm such as the Renogy Core Mini
  • Group 8D batteries are larger at 20.75-21 inches (527mm) L x 11-11.1 inches (280mm) W x 9.88-10 inches (251mm) H
    • Group 8D battery boxes are generally 21.0” x 11.8“ x 10.3” H
  • interiors of vehicles get HOT on sunny days - this may severely impact the life span of the battery if exposed to long periods over 40degC
    • LiFePO4 batteries last much longer if kept below 30degC
    • even an August winter day in Melbourne will give around 30degC in the boot of a Subaru under the hide

Types of lithium batteries

  • many lithium batteries risk explosion if they are short-circuited (ie. the positive and negative terminals touch each other via a conducting object)
    • ensure the terminals are protected from accidental metal contact
    • always use a fuse on the positive cable connected to the battery
    • don't carry smaller batteries such as power tool batteries in your pocket with your car keys!
    • this is much less likely in 12V LiFePO4 batteries as they have the added protection of a built in BMS  which protects and shuts the battery down in the event of Short Circuit, Over charging, Low discharge, Over and under Temperature

Li-ion polymer batteries

  • these are the kind found in laptops, smartphones, power tools, e-bikes and most 18650/21700 batteries and similar as they have a high energy capacity for the weight
  • each battery cell is usually 3.7V
  • they are prone to exploding with a difficult to put out fire if the chemicals become exposed to oxygen by either:
    • they are punctured or crushed (eg. in a rubbish truck which compresses the rubbish, you drop your phone on a flight then move your chair and it crushes it)
    • being old or damaged and placed on charge for too long - they then swell up, split or melt open (especially if the casing is plastic) and can catch fire

lithium NCM batteries (Lithium Nickel Manganese Cobalt Oxide (LiNiMnCoO2) )

  • these are generally the ones used on electric cars as they have a high energy capacity for the weight
  • each cell has a higher voltage of 3.7V compared to 3.2V for LiFePO4 and have more capacity per weight of 150-200 Wh/Kg compared to 100-150 Wh/Kg for LiFePO4
    • HOWEVER, has a poorer Depth Of Discharge (DoD) of only 80-90% (ie. should recharge when falls to 10-20%), whereas LiFePO4 can be used down to 0%.
  • some say they charge better in cold temperatures but do not cope as well with hot conditions compared to LiFePO4
  • are much more likely to have runaway thermal explosions than LiFePO4 and they release oxygen whereas LiFePO4 doesn't and also releases more flammable gases than LiFePO4 in failure
  • poorer life span than LiFePO4:
    • expected cycle life of about 2000-2500 cycles. It can provide full power for about three to four years but then suffers fast degradation
    • LiFePO4 batteries tend to have has a typical cycle life of about 5000 cycles (although many are only 3000 cycles). It can perform optimally for seven to ten years, followed by slow degradation
  • for longer life, should only be charged to 80% full whereas LiFePO4 can be charged to 100%
  • are more expensive than LiFePO4
  • are less environmentally friendly as contain cobalt

standard LiFePO4

  • these have a cell voltage of 3.2V and can produce 100-150 Wh/Kg
  • generally use a combination of generally less expensive standard 3.2V cylindrical cells or prismatic cells
  • far safer than Li-ion polymer or lithium NCM batteries but have less energy capacity for weight
  • have a long life if used well - usually 2000-4000 cycles down to 80% charge which should last most people at least 10 years and perhaps even 20 years making them much less expensive than most other battery types including lead acid over a battery life time although more expensive to buy than a lead acid battery
  • LiFePO4 generally do not off-gas unless they are damaged
    • manufacturers nevertheless recommend placing 200Ah or larger batteries in ventilated spaces separate from sleeping areas or LP gas especially if charging them - off-gas, if it does occur, is generally flammable hydrogen and toxic carbon monoxide, or if the cells have been punctured, a respiratory irritant electrolyte vapour
    • toxic gases will be released in the very rare instance thermal runaway / explosion occurs
    • they are much safer than lead acid or AGM batteries in terms of off-gassing as these off-gas hydrogen during charging, and can produce toxic hydrogen sulfide if overcharged, and risk leaking sulfuric acid.
  • should not be charged at temperatures below 0degC (some actually have internal heating systems) or above 50degC
  • some have internal Bluetooth functionality so you can see its current status using a smartphone app
  • they are of two main types:
    • cylindrical LiFePO4 batteries
      • these are similar shape to AA batteries and are 3.2V each cell and come in various sizes and capacities such as 18650 1.6Ah 3.2V batteries
      • these are the standard batteries used for:
        • many portable devices where battery weight is not a major concern such as portable radios, night vision devices, camping lamps, etc
        • the creation of 12V LiFePO4 batteries which use a lot of these in series and in parallel and managed by a battery management system (BMS) to optimise each cell's charge state
    • prismatic LiFePO4 batteries
      • these tend to be larger rectangular cubes or pouches
      • if not adequately protected, these have a higher risk of explosion than the cylindrical ones which are generally more sturdily encased in aluminium
      • they were often used to create budget 12V LiFePO4 batteries

high density LiFePO4 batteries

  • newer more expensive versions use combinations of 3.2V high density 160 Wh/kg prismatic cells - these come in 105Ah, 280Ah, 200Ah - 4 of which are needed to make nominal 12.8V batteries
  • Grade A have longer life spans
  • these are generally better protected than earlier budget prismatic cells
  • example manufacturers of these cells are EVE and REPT

new LiFePO4 solid state batteries

  • these are coming in 2025, are more expensive than standard LiFePO4 as they have 70% less liquid than standard LiFePO4 batteries which gives more capacity for weight, higher thermal stability (can now charge down to minus 10degC instead of only 0degC), higher charge and discharge rates, longer life with 6000cycles at 80% DoD, and are puncture resistant (punctures can cause a standard battery to catch on fire)
  • companies like EVE are aiming to create batteries with 400 Wh/kg by 2028 which would give them 4x as much capacity in the same weight as standard LiFePO4 batteries

Battery specifications

  • capacity is rated in Ah (amp hours)
    • this is easily converted to Wh (watt-hours) by multiplying by the nominal voltage (ie 12.8 for a 12V LiFePO4 battery)
    • 100Ah will run a 120W device for just over 10hrs (although you should only go down to 20% charge at most - so 8hrs is better)
      • a car fridge used carefully may only need 1A per hour
      • a “48W rated” car heated cushion will generally average 1A per hour as it cycles on and off
      • a 150W 12V car demister heating fan for your tent will use around 12.5A per hour and rapidly deplete your battery!
      • most laptops run at 65W
      • by comparison, many portable devices containing lithium batteries use 3.7V 2700mAh batteries and these contain ~10Wh of charge compared to 1200Wh in a 100Ah 12V battery!
    • see battery capacities compared, how much do you need?
  • nominal voltage
    • this is the specified operating voltage for use as a single battery and for LiFePO4 batteries is usually 12.8V as they contain 4 LiFePO4 3.2V battery cells connected in series (some may have additional ones connected in parallel else well to increase capacity)
  • voltage range
    • LiFePO4 batteries have a Battery Management System (BMS) which will usually prevent:
      • over-charge - will cut off charging if voltage exceeds a specified amount (usually around 14.6-14.8V)
      • over-discharge - will cut off discharging if voltage falls below a specified amount (usually 10-11.7V)
  • life span is usually rated in number of cycles for a given depth of discharge (DoD):
    • the greater the amount to deplete the battery to each time, the less of these cycles you get
    • good LiFePO4 batteries are generally rated at least 2000-4000 cycles for 80% DoD at 25℃ and at discharge/charge rates of 0.2C
      • hence if twice a week you use them down to 20% charge and recharge fully, they should last you well over 10 yrs of use (2000/(2 x 52weeks) = almost 20yrs! )
  • maximum charge / discharge rates
    • in general you will want to charge the battery at an optimum rate (this may be 0.2C but as long as it is above the manufacturer's minimum charge rate) without over-heating the battery as heat kills life span
    • charge/discharge rates are usually in amps but can be in terms of C where 1C is a complete charge or discharge of capacity within 1 hour (2C is within 30 minutes)
      • thus for a 100Ah battery with a 1C max discharge rate this equates to 100A discharge rate
      • most quality LiFePO4 12V batteries have a 0.5-1C discharge rate hence a 1C 200Ah battery will allow 200A discharge which equates to 2560W and will suffice to run a 2000W AC inverter
    • power stations often have limited charge rates of 5A
    • most batteries have a 0.5C charge (ie 50A max for a 100Ah battery) and thus charge in 2 hours
  • ability to connect similar units in parallel
    • this allows increased capacity but needs care in ensuring similar capacity and chemistry batteries and similar charge cable lengths to each to provide efficient balancing
  • ability to connect similar units in series to increase voltage to 24V or 48V
  • weathersealing
    • usually rated in IP standards; you do not want lithium cells getting wet!
  • terminals
    • M6 or M8 bolt “button” terminals
      • these have a nut to hold down your cable's connector ring with M8 being more heavy duty than M6
      • the bolts are often removable for ease of storage etc
      • one should not exceed the maximum torque when tightening these nuts, although experienced users will tighten by feel
    • automotive post (AP) or “round terminal”
      • these are the standard type of terminals in most car starter batteries and require a clamp type connector
  • smart electronics such as:
    • automatic self-heating when temperature falls below 5degC
    • SOC monitor capability
    • intelligent auto-balancing when connecting to same batteries
    • Bluetooth for smartphone app access to BMS and SOC
  • if you want to use an AC inverter with a battery to run a 1200-2000W AC appliance you will need a higher capacity battery with higher continuous discharge rate
    • 1280W = 100A current from your battery and this can drop your battery voltage below its cutoff voltage and this will then result in sudden loss of power
    • if running such high wattage devices, you probably should consider a caravan style 200 or 300Ah LiFePO4 battery but it won't fit in a standard battery box

Joining batteries together

  • in general this should ONLY be done with compatible batteries of the same chemistry (ie. LiFePO4 joined to LiFePO4)
  • there are two main ways to do this:
    • in series to create a higher voltage
      • connect negative of one battery with the positive of another battery
      • creates a final voltage which is the sum of the voltages of each battery eg. 2 x 12V batteries will make a 24V system
      • BUT if you use different capacity batteries, the lower capacity battery will run out first and the circuit will break - hence the capacity of the system is the same as the lowest capacity battery in the system
      • THUS to do this you really need to use the same battery types, of similar capacity and age so they both deplete at same rate and not stress one of them
      • you probably only want to do this if you want to run very high wattage devices (eg. 2000W) for long periods such as caravan air conditioners but you would need a 24V AC inverter and 24V charger
    • in parallel to create a combined capacity but same voltage
      • connect positive of one battery with the positive of another battery and negative to negative
      • must use same type of battery and similar voltage batteries (don't have to be exactly the same as they will equalise in the system)
      • your output then is from the negative of one battery and the positive terminal of the other battery
      • voltage stays the same but you get the combined capacity in Ah
      • BUT you must ensure your discharge or charge currents do not exceed the lowest rated charge/discharge currents of the individual batteries - so if using a 100Ah and a 300Ah battery, your discharge current will be limited to the 100Ah battery current which is usually 100A - and obviously, you cables connecting the batteries must be rated at a higher level than this !
      • you would only want to do this if you had a permanent battery setup such as in a caravan or at home to avoid you having to manually connect the charger to each battery every time it needs to be re-charged, or to avoid having to connect the AC inverter to a different battery when one goes flat.
      • a better option is to have a higher capacity battery in the first place as this will generally provide much higher discharge currents
        • combining 3 x 100Ah batteries will give same capacity as one 300Ah battery but your max. discharge current will be only 100A (1280W and with 90% efficiency rate of an AC inverter this would mean max device usage of ~1150W) with the 100Ah batteries whereas the 300Ah will generally allow 3x more current and easily manage a 2000W AC inverter

240V AC-DC chargers for 12V LiFePO4 batteries

  • NB. these are NOT needed for power stations as these generally have a built in charger
  • assuming you have a 100Ah LiFePO4 battery and you wish to charge it at the camp ground's laundry or other AC outlet and you don't want to be hanging around for many hours waiting for it to charge, then you should consider buying a high current (eg 25A) lithium charger albeit at higher cost, size and weight than low current chargers
  • you do need to check the max. rated charge rate for the battery to avoid overheating and damaging it but nearly all 100Ah LiFePO4 batteries should easily take a 25-30A charge rate.
  • you can potentially use two chargers in parallel for faster charge rates 1) however this may cause problems particularly as the battery is getting to full and needs cell balancing. Chargers generally turn output off momentarily to check voltage of the battery and if there is another charger going then it may not get an accurate reading, thus having multiple chargers running is probably not recommended, especially if each charger is not isolated to back current from the other charger by use of a schotkey diode to ensure current only runs one way. Do this at your own risk and with care!
  • these chargers will also charge lead acid, AGM, and lead calcium batteries
  • do not charge LiFePO4 batteries below 0degC or above 50degC.
  • Victron BlueSmart series have a smartphone Bluetooth app which allows you to change settings and monitor charging as well as retain a history of charging sessions. Plus the app lets you set them as DC out power supplies.
  • recommended charging current for LiFePO4 batteries is typically 0.2C to 0.5C (20A to 50A for a 100Ah battery), but charging at lower currents is not harmful—just slower and may be more gentle on the cells - in general, aim for a 25A charger unless you have a 200Ah or bigger battery

12V 40-50A chargers

12V 20-30A chargers

  • Victron BlueSmart IP22 12V 30A chargers
    • silent night mode which runs at half or quarter charge rate depending upon model
    • conventional screw-down electrical connections and is not shipped with cabling
    • 94% efficiency;
    • $AU344 for triple outlet charger can charge up to 3 batteries at once to max. total current of 30A
    • $AU329 for single output charger
  • Victron BlueSmart IP65 12V 25A
  • Renogy 20A charger
  • Kickass 32A ACDC Flexicharge charger
    • 8/16/32A;
    • 298 x 152 x 87mm;
    • one reviewer suggested that “it really doesnt have a proper LiFePO4 charge profile. LiFePO4 cells should be charged purely bulk at a fixed Voltahe and fixed current to 3.65V per cell or 14.6V for a nominal 12.8V battery and then disconnect. This charger in Li setting, only charges to 14.4 and exactly the same as a Lead Acid battery, ie, bulk, then a reduced current absorbtion then a lower voltage float.” Response from Kickass “The lithium charge algorithm used in our Flexicharge 32A Smart Charger was custom-designed by our engineering team, specifically for use with our KickAss LiFePO4 batteries and their internal BMS. Our Li setting uses a proper CC-CV (Constant Current – Constant Voltage) profile - it charges at max current until the battery reaches 14.5V, then holds that voltage while current tapers off until the battery is full. While it may appear similar to traditional lead-acid charging at a glance, our Li profile does not include a float stage, which is key for LiFePO4 chemistry. This setup has been extensively tested to ensure it’s safe and effective for our battery range.”
    • https://kickassproducts.com.au/products/kickass-flexicharge-12v-32-amp-9-stage-automatic-agm-and-lithium-battery-charger $AU249 on special

12V 15A chargers

Battery boxes and Power Stations

no battery box, use a power box instead

  • use an Anderson plug input from your 12V battery
  • have a number of output plugs
  • a great solution for vans or 4WDs where the 12V battery is securely stored with terminals protected from short circuits and the power box can be mounted on a wall or similar fixture
  • KickAss 12V Mini Power Box
    • 4 USB 2.1A Ports, 1 USB-C PD 18W port, 1 USB QC 3.0 18W port, 3x 12V Cig Sockets and 2x Anderson-style input/outputs + the main 12V battery Anderson plug with 85cm 8B&S cable input
    • USB ports have a protective dust cover
    • the three 10A cig sockets are collectively fused via 30A blade fuse (a spare is included inside the unit)
    • 40A total auto reset circuit breaker for the Anderson plugs
    • battery meter, on/off switch, light switch, 3 stage LED light, 2 mounting point, 180x120x58mm, 905g;
    • can connect a regulated solar panel to provide additional power via an Anderson plug
      • A battery MUST be connected prior to connecting a regulated solar panel. The regulated solar panel MUST be disconnected from the Mini Power Box before the battery is disconnected.
    • $AU189

Battery boxes

general characterististics

  • these not only house and protect your battery but provide a range of very useful and convenient functions which may include:
    • ability to re-charge the battery via Anderson port or external terminals to allow either:
      • 240V input
      • solar panel input
      • DC input including from your car's main battery and alternator system
    • various DC output interfaces such as:
      • cigarette socket outlet
      • USB port
      • USB-C port to charge the latest laptops
      • 50A Anderson bidirectional plugs - you should aim to have at least 2 of these
      • 175A Anderson outlet - probably don't need this as you can use a jump starter with these batteries, the only other potential use if for high output devices such as 3000W AC inverters but these will drain the battery very fast!
    • possibly a built-in AC sine wave inverter with 240V output
      • HOWEVER, whilst LiFePO4 batteries generally allow rapid discharge rates, the lead acid batteries are not designed for rapid depletion, only low current draw appliances should be run - higher draw appliances may need a petrol power generator with an AC inverter
      • a good inverter will cost around $AU499-699

examples of battery boxes with AC inverters

  • ArkPak 730P $AU699 - 300W Pure Sine Wave Inverter; the only battery box on the market that has a built-in AC-DC and DC-DC charger; battery management system and a dual-battery alternative; 50 amp Anderson socket; 2x 12V sockets; 1x 5V USB 2.1amp socket; 7 Stage smart charge; compatible with LiFePO4 although some report buggy battery status issues; 4.6kg;
  • Engel Smart Battery Box Series 2
    • $AU549, 300W AC inverter; Output Power: 1 x 12V 10A Cigarette Socket | 1 x 12V 10A Engel Posi Fit Socket | 1 x 12V 50A Anderson | 1 x 240V AC 300W Modified Sine Wave Socket | 1 x 5V 2.1A USB | 12V 100A External Terminals
    • supports LiFePO4 up to 130Ah

examples of battery boxes without inverters:

  • Dune battery box
    • light and flimsy but great value option, has 2 Anderson plugs plus 1xcig, 2x USB, terminals, meter
    • note that the power off/on switch only controls the cig/USB outputs not the Anderson plugs!
    • Max. battery dimensions 325mm long x 185mm wide x 200mm tall
    • on special for $AU69
  • Kings Portable:
    • 2x Anderson plugs; 2xUSB, cig plug; circuit breaker; volt meter; ext. terminals;
    • max. battery up to 120Ah: 230H x 185W x 360L mm shortest battery length: 260mm;
    • 1.6kg; ext: 280H x 265W x 440L mm (too long)
    • $AU59
  • KT Portable box $AU99
    • lighter at only 1kg, top handle, 2x USB, 2x cig lighter outputs; charging via rapid charge battery charger terminals; for batteries up to 120AH;
  • BWB 12.8V 100Ah 1280WH LiFePO4 Deep Cycle Battery Stainless Steel Box w/ Accessories Model SS12100A21
    • stainless steel compact box with voltmeter/capacity meter/Bluetooth, 2x Anderson, USB, Cig lighter
    • PLUS 100Ah LiFePO4 battery
    • 32.3 x 19 x 19.5 cm; 14.5kg; $AU850 ($AU790 without Bluetooth monitoring)
  • HardKorr Heavy Duty Battery Box
    • $AU179 3.2kg; supports Lithium; 1 x dual USB output; 2 x cigarette plug outputs; 4 x 50A Anderson plug inputs/outputs; 1 x 175A Anderson plug output for jump starter leads (opt) or an external AC inverter (opt);
    • max. size battery: 330mm (l) x 180mm (w) x 240mm (h) (equates to 120Ah LiFePO4 battery)
    • 41x32x24cm external;
    • charging only via Anderson plugs;
    • make sure you make an Anderson plug connection to your AC battery charger otherwise you will need to unscrew the screws holding the lid down.
    • available in Melbourne from Every Battery Kensington
  • Ardent Heavy Duty battery box:
  • iTechWorld GoFurther Battery Box:

Power stations

  • these have a battery and box all in one sealed unit
  • at present some of these are older lithium ion technology rather than LiFePO4
  • convenient but generally poor value for money and limited DIY repair options (batteries are generally not user replaceable)
  • see 12V DC and 240V AC output power stations

wall mounted Control Hubs

  • those with 4WDs and permanent set ups or with caravans may prefer to have the battery remotely accessible (ie. not readily accessible) and use a wall mounted Control Hub instead of a battery box, which has input from the battery and a multitude of outlets
  • Kickass Control Hub
    • 4 Anderson ports, 5 X 20A Pre-wired fused switches, 4 x USB ports ( 2 x 2.4A, 1 x QC3.0, 1 x USB C) and 2 x Cig sockets. Fuses. Voltmeter. ow voltage alarm below 11V.
    • 400x305x80mm (plus extra 30mm depth from fuse housing); 4.15kg
    • $AU399
  • KT DC Power Link 4 Way Connect With Smart-Touch LCD Screen
    • 1 Anderson plug input, 3 Anderson plug outputs, 2 USB outputs, LCD touch screen display of power usage and voltage as well as turn off individual outputs, max 50A;
    • $AU139

12V LiFePO4 deep cycle batteries

pros and cons of LiFePO4 batteries

  • these are lighter, safer, but currently are much more expensive compared to a deep cycle lead acid battery
  • a 54AH LiFePO4 battery equates to 110AH lead acid as it can go down to full discharge instead of only about 50% discharge.
  • 5-10x the life of an equivalent Lead Acid AGM battery and weigh less than half as much and has far less self-discharge rates, retaining 80% of charge by 12 months compared with only 40% for typical lead acid batteries
  • charges 3-4x faster, some 100AH batteries charge in 1-2 hours!
  • More resistant to vibration, less likely to be damaged and have a more stable output voltage which tends to be maintained until capacity falls below 30%
  • LiFePO4 batteries are less likely to explode when over-charged and maintain charge longer than other lithium batteries and unlike other lithium batteries, do not suffer from thermal runaway
  • it should have a built-in battery management system to ensure all cells are charged evenly, and to provide short-circuit protection, reverse polarity protection and over-current protection as well as ensuring a consistent output
  • usually require a special lithium charger
  • Deep cycle ones are not suitable for use as a primary vehicle starting battery and cannot be used under the bonnet as it gets too hot
  • disconnect the loads when you are storing the battery for long periods and store at 30~50% SOC
  • avoid continuous maintenance or trickle charging
  • do not charge below 0C
  • there are many “cheap” LiFePO4 batteries on the market including some listed below - these may or may not have quality undamaged cells, quality build, or properly balanced cells and may have lower capacity than specified, shorter life spans and have specific requirements regarding charging, etc - do your research!
  • some cheap budget end batteries claim 2000 cycles but this is at only 30% DOD in which case you may find there are under 1000 cycles for 80% DOD whereas better batteries may claim 4000 cycles at 80% DOD! You are probably getting better value in the long term from the 4000 cycle battery even if it is twice the price!
  • reputable manufacturers include:

models able to fit on floor of rear seats of cars

  • rear seat floor of a Subaru Outback is ~480mm wide by ~200mm deep (more if you move the front seat forward)
  • some of the Power Stations mentioned above will fit as well
  • remember to secure them so they don't become lethal missiles in an accident
  • a 100Ah battery in a battery box will just squeeze onto floor of front passenger seat of most larger cars

compact, light 2.5-5kg 15-40Ah models

relatively small 6-8kg 50-55Ah models

  • BigWei BWB Model SS1250 50Ah in Stainless Steel Box
    • 6.9kg; 18.8 x 16.4 x 14.8 cm (18cm total height including terminals); 8000 cycles
    • $AU390 on special ($AU450 with bluetooth)
  • ITechWorld 48AH slim version
    • designed to be wall mounted so not as good for the floor of a rear seat
    • can be connected in parallel or series up to 4 of same units
    • 7kg; 300x90x210mm; M6 stud; built in cig lighter port one end and 2x floor-level mounted Anderson ports at other end;
    • $A599 ($AU499 on special)
  • iTECH054 12V 54AH LiFePO4 Deep Cycle
    • 7kg 648Wh; charge 25-55A; IP65 waterproofing; can cycle up to 5000 times at 50% depth of discharge; can use most existing chargers; can be connected in parallel/series; $AU499 based in Perth, WA
  • VoltaX 12V 50Ah
    • ~6.6kg 640Wh; charge 10-50A; requires own Li charger; $AU329
  • DryPower Deep Cycle Lithium 12.8V 50AH 640Wh battery
  • Drypower 12.8V 55Ah Lithium Iron Phosphate (LiFePO4)
  • Renogy 50Ah
    • 197x166x171h mm; 6.7kg; 2000cycle 80% DOD; M8 terminals;
    • $AU399;

100-130Ah slimline models

10-14kg 100-140Ah similar size to standard lead acid batteries

140-200Ah 12V LiFePO4 batteries

300Ah 12V LiFePO4 batteries

with car jump starting capability as well

Lead acid batteries

characteristics

  • these may be a deep cycle or dual purpose battery
  • A deep-cycle battery is a battery designed to be regularly deeply discharged using most of its capacity, unlike a normal starter battery which is designed to only use a small part of its capacity in a short, high current burst to crank the engine.
  • deep cycle batteries cannot be used to crank start your vehicle, but a dual purpose one can.
  • there is a trade off between the battery's depth of discharge and the number of cycles of discharge and recharge it is capable of and there is an inverse relationship between these
  • these deep cycle batteries are generally designed to discharge slowly over 20-100hrs such as with a fridge, and if they are discharged rapidly such as over 1 hour, you will only get to use around half of the usual capacity and the number of cycles will be reduced
  • none of these lead acid batteries should be fully discharged as this will shorten their life span, and should only be discharged to 20% of capacity at most (usually 50%)
  • Absorbent glass mat (AGM) batteries handle higher temperatures better, self-discharge more slowly, will charge more quickly (usually within 3hrs from a standard car alternator), have deeper discharge depths, are totally sealed, more robust, do not need topping up with water, can be safely mounted inside a car as they do not need to be vented externally
  • these can explode if over-charged or their release valve fails (if they have one)
  • these will usually set you back around $AU230
1)
https://www.youtube.com/watch?v=zROCzxXbuNo
2)
https://www.youtube.com/watch?v=UuhdkZljy2Q
australia/12vbatteries.txt · Last modified: 2026/02/10 10:43 by gary1
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