thanks so much for the great info! 🙂
i am currently thinking of Mach8 Plus HVAC, 720 watts solar, and 200 amp hours Lithium.
perhaps in full sun, i wonder how long i could run the HVAC off solar? with battery buffer. That would be wild.
I recently gained a bit of Lithium hands on experience by helping my neighbor convert his new 8×12 V nose cargo trailer into a camper…
His set-up includes one 100a LiFePo4 battery, a 2500w pure sine inverter charger, a 7.5 cf dc only refer (with a 12v danfoss compressor), a PD 40a Li converter charger, two 200w solar panels with PWM controller (soon to be replaced with a MPPT), Victron SOC meter (and shunt), a sub-panel (for air and house plugs), and a 11k btu Mach 1 P.S. air cold…
What’s so interesting is just how high the charge acceptance rate of the Lithium battery is (meaning a uber fast harvest!) and that the voltage stays nearly constant throughout the entire discharge…
He can run the air cond for about an hour (comp cycling) via the inverter and single battery (this, prior to adding solar…), and he inadvertently once allowed the battery to discharge all the way down to 6% SOC – this, with the air still running!!…Luckily no damage to anything, he was only alerted to the low SOC situation via the sounding from the Victron SOC meter alarm…
He wanted to be able to run the air cond (without struggling with the genny) for brief periods during a short roadside stop…It works perfectly!
Now with solar added, 12v refer is easily self-sustaining until the sun sets then consumes thru the night only about 25-30% battery capacity by sun up, with battery then fully restored by about 11:30am in the month of July…
Starting out with nothing but an idea, it was a fun project (lots of planning and wiring on my part) to see thru to the end, and even better because EVERYTHING worked out!!
To answer your question, 400w should work out perfectly (due to the uber high receptivity rate of Li), though (depending on low solar winter harvest and one’s energy consumption) I wouldn’t be afraid of having two batts, though I don’t see it as a requirement – in net terms, his one Li is easily equivalent to my two 6v golf cart batts which have never let me down …Just saying
Phil
