User Tools

Site Tools


australia:camping_offgrid

camping off-grid - batteries, solar, fridges

Introduction

  • one of the main issues when camping off-grid for an extended period is power supply to run fridges and other devices
  • for short periods, lithium ion batteries or lead acid battery may suffice but for extended periods these need to be re-charged and one does not want to rely upon running the car to re-charge them.
  • caravans often have gas powered fridges

portable car fridge/freezer

  • these are generally DC and 240V AC powered and should have a 3 stage battery protection system to turn the fridge off in the event the vehicle battery is going flat (if the fridge is being powered by the main vehicle battery)
  • most have a digital interface which allows user to dial in the desired temperature from 10degC down to minus 10degC
  • some have dual compartments - one as a fridge and the other as a freezer
  • the best size for most families is a 60L capacity but 45L may suffice for a couple
  • a 45L model will generally draw 1A to maintain contents at 5degC in 32degC ambient temperatures
  • fruit and veges are generally placed in the warmer upper parts to avoid spoiling by freezing
  • a 45L model will cost $AU399-$AU699 - check to see if it will fit a wine bottle standing up if this is important to you
  • Dometic CF models are budget level fridges which are more likely to have issues including failure of the lid lock mechanism
  • Dometic CFX models tend to be the favored models for their better build quality but are more expensive

Off-grid power supply

  • there are a variety of components required

solar recharge battery system

main options

  • fast charge, high capacity but heavy and expensive
    • eg. 120AH LiFePO4 battery (~13kg) or 55Ah 8kg in a high end battery box (~4kg) with BMS with 20-100A charge rate
  • fast charge, medium capacity
    • HardKorr Heavy Duty Battery Box $AU219 3.2kg
    • 15A battery charger designed for LiFePO4 with Anderson plug connection modification $AU250-300
    • Drypower 12.8V 55Ah Lithium Iron Phosphate (LiFePO4) 8kg $AU799 or a 100AH battery for same price but 13.5kg
  • slow charge, medium capacity, light weight and compact power station
    • eg. Companion 40Ah Rover (~7kg) but only 5A charge rate which limits solar charging

choice of battery

  • lead acid battery
    • these may be a deep cycle or dual purpose battery which may provide 12V 110Ah on a full charge
    • 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
    • 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
  • lithium iron phosphate batteries
    • these are lighter, safer, but currently are much more expensive for the battery which generally has much less capacity than a lead acid battery
    • a 54AH 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
    • eg:
      • 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 Lithium Ion Battery LiFePO4 Deep Cycle ~6.6kg 640Wh; charge 10-50A; requires own Li charger; $AU329
      • VoltaX 12V 100Ah Lithium Ion Battery LiFePO4 Deep Cycle ~10kg 1280Wh; 2-4hr charge 20-50A; requires own Li charger; $AU469 (Plus version halves the charge time $AU649)
      • DryPower Deep Cycle Lithium 12.8V 50AH 640Wh battery
      • Drypower 12.8V 55Ah Lithium Iron Phosphate (LiFePO4)
      • Pure Energy LiFePO4 12V/100Ah 1280Wh Deep Cycle Lithium Battery
      • Aeson SUPERPACK 12.8V 100Ah 1280Wh LiFePO4 with Bluetooth 100 Amp BMS 4 x Series / Parallel
  • jump starter battery pack
    • eg.
      • Powertech MB-3759 12V/24V 1000A Jump Starter
        • 22AH lithium polymer ion battery; jumper leads; LED torch; USB 5V/2A output; no cig lighter output; 2.3kg; 15V/2A charge; $AU295-369
      • Powertech MB3736 12V 17Ah Jump Starter with Air comp USB LED light
        • 17Ah sealed lead acid; 2x USB 5V/2.1A; 1xcig lighter; 8.6kg; $AU199
      • Powertech MB3738 12V 18Ah Jump Starter With Air Compressor and Inverter (discontinued)
        • 18Ah deep cycle lead AGM; 5xUSB 5V/2.4A; 1x cig lighter; 300W AC inverter; 7kg; $AU149;

battery box

  • these not only house your battery but provide a range of very useful and convenient functions which may include:
    • ability to re-charge the battery via 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
      • DC out port
    • possibly a built-in AC sine wave inverter with 240V output
      • HOWEVER, as 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 one will cost around $AU499-699
    • eg:
      • 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
        • $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);
        • charging only via Anderson plugs; optional 50A Voltage-Sensitive Relay (VSR) kit;
        • 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
      • 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;
        • need to buy a battery charger

power stations

  • these have a battery and box all in one sealed unit
  • eg.
    • Companion Rover lithium 40AH Power Station
      • $AU599
      • LiFePO4; 6.5kg; 512Wh; 270 x 154 x 242 mm;
      • max. concurrent output 10A
      • max. solar charge rate 5A
      • outputs: USB 3.: 2 x 5V/2A, 12V/1.5A; USB-C: 1 x 5-20V 3A max. 60W; 2x DC5525 12-16.8V 10A DC Plugs; 1 x 12-16.8V/10A cig; 1 x 12-16.8V/10A 2-pin Engel-type; 12-16.8V 10A Anderson;
      • inputs: 14V 5A DC; 16.8V 5A AC, Anderson, 18-20V 5A direct solar (MPPT controller included in station)
    • Companion Rover lithium 70AH Power Station
      • similar to above 40AH version; NMC (LiNiMnCoO2) battery; $AU1099; 6.8kg; 800 Charging Cycles down to 80% SOC;
      • max. charge rates: 240V AC 77-84W 5A; cig lighter 126W 9A; Anderson plug solar 13-30V 12A (MPPT controller included in station);
    • Hyundai 1000W / 2000W max LiFePO4 Lithium Power Station AC/DC
      • $AU2199; 14.8kg; 84Ah;
      • outputs: USB 3.: 4 x 5V/3A, 9V/2A; USB-C: 1 x 18W, 5/9/12V; 2 x 5.5mm DC Plugs; 1 x 12V/10A cig; 2x 240V AC; 1 x EC5 150A Max jump starter;
      • inputs: 5-24V 120W solar; 240V 120W AC;
    • Sunovo SPS500
      • 35Ah 504Wh lithium ion; 3.5kg; $AU599
      • outputs: USB2 5V2A; USB3 5V/3A; 45W PD; 2xDC 12V/10A; 1xcig; 300W pure sine wave AC inverter
      • inputs: solar (5hr charge with 100W panel); 5-6h charge with AC; 6-8hr charge with car DC;

solar panels

sockets and other miscellaneous issues

  • MC4 connectors
    • weathersealed single wire connectors usually used on solar panels
  • Anderson 12/24V socket
    • a specialized socket designed to handle a high, continuous load which allows charge from your car battery or solar panel to flow to your accessory battery in dual battery systems and hence can be used to connect car to caravan
    • can also be used powering high-draw 12-volt accessories such as fridges and air compressors
    • they come in different current sizes eg. 50Amp
  • Merit 12/24V plugs
    • similar to cigarette lighter plugs BUT smaller in size and have the advantage of a superior rugged construction and higher current carrying capability
    • can be converted to cigarette lighter plugs
  • DC-DC car charging
    • newer cars may not generate enough power to charge a battery so you may need to wire directly to the cranking battery with a DC-DC charger and a voltage sensitive relay (VSR) to stop draining your car battery when the car stops
      • crimp don't solder as solder gets britte and breaks on corrugated roads
      • cover wires with corrugated pipe to avoid wires rubbing away on sharp edges
      • fix wires to chassis every 30cm
      • charger should be near aux battery to avoid charge voltage drop over a longer distance and a fuse on the positive wire between them
  • dual battery wiring kit without DCDC:
  • tow bar extension wiring:

petrol power generators with AC inverters

  • these are important particularly if you need to run higher current draw appliances such as heaters and microwaves
  • they can also be used to re-charge your batteries if the solar is not adequate
  • make sure you get one with pure sine wave inverter to give clean AC outputs that won't damage your electronics
  • also check how noisy it is as they are perhaps the most hated accessories at camp grounds due to their noise (as well as exhaust fumes)
  • some have parallel stacking capability to combine units for greater power output
  • examples:
    • Ryobi RIG2000PCB 2000W Petrol Digital Inverter Generator $AU999 - 24.4kg 2 x 15A sockets and 2 x USB outlets
    • DeWALT DXIG2200 2200W Inverter Generator $AU1299 - 22.5kg
    • Full Boar SD2200I 2200W Inverter Petrol Generator $AU798 - 21kg, 61db
    • Yamaha EF1000iS 1000W 1 KVA Silent Inverter Generator $AU1299 - 12.7kg, 47-57 dBA/7m

more powerful lithium ion off-grid solar kits for homes or sheds

    • Victron 12v 1200w pure sine wave phoenix inverter
    • DCS 12v 200Ah lithium battery storage
    • 31.5A Votronic solar controller
    • Trina solar panels (2 x 310w mono)
    • Victron Battery Protect (low battery voltage protection)
    • 333Ah 48V dual lithium battery system (2 x DCS PV 10W LFP batteries which provide total 15kW continuous load) = 198kg, $AU17,999 for batteries alone (cw 900kg of lead acid cells)
    • Selectronic 7.5kw SP PRO solar controller
    • Fronius 8.2kw Primo inverter
    • 10 ~ 12kw of solar PV panels - should provide around 19kWh even on the most cloudy days in lower latitudes and average winter evening usages for a house runs at around 10kWh.
    • +/- 5kVa diesel backup generator

wiring

  • battery packs wired in parallel (reds to reds and blacks to blacks)
    • red wire of 1st battery to main fuse which connects to shunt which connects to distributor box
    • black wire of last battery to shunt then to distributor box
  • distributor box (eg. Victron Lynx Distributor)
    • earth wire to chassis ground
    • red and black wires to the DC fuse box in the AC-DC distribution panel to supply DC outs
  • inverter charger (eg. Victron Multiplus Inverter Charger 3000 W 12V)
    • red and black to distributor box DC in
    • earth wire to distributor box earth
    • 3 wires (active, neutral, ground) from Shore power to AC in
    • 3 wires (active, neutral, ground) from AC out to AC-DC distribution panel with a breaker
    • thus the inverter charger can:
      • combine amps from Shore power AC (eg. 30A) with the amps from the batteries if usage exceeds the Shore Power amperage
      • if power usage is less than the incoming Shore Power AC, then unit can use this to charge the batteries via the same cable to the distributor box
      • provide AC outlets
  • MPTT solar controller
    • red and black “battery wires” to distributor box
    • earth wire to inverter charger earth
    • red and black “PV” / solar wires“ to solar circuit breaker
  • solar panels are wired in series (or 4S2P pending requirements) and wired to a circuit breaker which is used as a disconnect
australia/camping_offgrid.txt · Last modified: 2021/05/02 16:26 by gary1