Have 3 x 100 amp batteries in the van and Im going to swap the 100 amp aux battery in the tug with a 200 amp (all batteries are lifepo4) , Im wanting to use the extra capacity of the aux battery when running the aircon off grid , have already done a test using the existing Anderson connection between tug and tow with both battery sets remaining in float while the sun was ok so 13.70 volt .
Ive discovered that the van also had another heavy set of wires connected to the caravan plug that went to the fridge cavity but were capped off and unused , Im thinking of joining this set with the Anderson set and connecting to the vans batteries fused with a midi fuse as the ando is also fused with a midi fuse .
My question is while it all works ok using the existing 100amp aux battery , will I be Pushing my luck going to 200amp in the tug .
According to the shunt the aircon max battery drain is 75amp just after start up but tapers down , and inverter is 2000 watt which handles the aircon easy which is a new MyCoolman aircon .
Your question is not clear. I can't tell what you're doing with your batteries.
And, by the way, never, ever and double ever use 12V for high current applications - 24V or better still 48V.
However: my caravan AC uses 1300W when running so if I run it from 1400h to 1900h it will use about 3.2kWh - assuming a 50% duty cycle.
With LiFePO4 in order to do that without running the batteries flat you'll need about 4.5kWh of battery (preferably 7kWh) kWh = 12V x Ah.
BUT - your bigger issue is where are you going to get 3.2kWh+ of charge from the following day in order that you can do it all again?
My advice is forget it. If you really wish to use an AC then a generator or caravan park is the way to go.
I have 800W of solar in Victoria and have never seen 3.5kW from them and, frankly, if I did then I'd decide it was too hot and move to somewhere I didn't need the AC.
Thanks BBN2 , we usually head north west during the Victorian winter and depending on which spot we go to depends on aircon use , just above James Price point you dont really need the aircon but Telegraph pool up further near Derby it would be handy .
I have no issue with recharging whats used if its sunny and Im in the right spot as far as no big trees go , I have decided to put a shunt on the 100amp aux battery and see what amps are being pulled when the Anderson plug is hooked up to the van and aircon is on , then recharge and retest with the 200amp aux battery to see the difference in amps being pulled from the aux battery .
Unfortunately the new aircon is not as off grid friendly as advertised unless they meant using a generator , the 10 year old aircon that was in it seemed to pull less once the inside cooled down to temp , the tests and real world running of the aircon when the ambient temps are over 30 degrees Celsius mean I need another 100 - 150 amp of battery to be comfortable with reserve capacity.
In ideal conditions Ive seen 45amps coming from solar charging for just the van the tug has its own system plus I have the ability to add extra panels if needed to either tug or van plus if desperate I could run the car and the dcdc or generator because the type of spots we go to we are usually by ourselves .
