I've lived with International's EPU setup for 4 years now and it's been okay. My biggest complaint originally was they needed new batteries fairly often as their capacity reduced. I've had an auto start truck for two years now and that's been great, but the starting and stopping can be a bit annoying at times.
I'm wondering if we, or the manufacturers could start making use of lithium battery tech for these electric apu setups. They make very large capacity batteries that can be repeatedly fully discharged without fully ####ting the bed like AGMs, and many are sized the same as group 31 batteries. That or have a compartment inside the heated interior for winter proofing them.
Anybody have any thoughts to add?
Lithium batteries for Electric APUs
You can but the biggest problem is lithium batterys dont do well in extreme hot or cold, they lose a lot of efficency and cant provide or store nearly as much power as is on the lable. However, there are some you can buy that are designed with those conditions in mind but they are spendy to the tune of $850+ per battery when i looked into some for my RV. There are some more general purpose ones that are cheaper but i have no idea how they stack up compared to lithium batterys designed for extreme weather.
AGMs more or less work anywhere. Plus they dont tend to explode in some conditions unlike lithium. I.E if you wreck or some swift ####### backs into you, or theres a short circut ect. Hence why they are prefered.
Its doable but honestly for the 3 to 5 grand it would cost to go lithium you may be better off just getting a small genny or diesel apu.BoxCarKidd Thanks this.
This is the video I watched. I can't vouch for the guy's objectivity, but he claims to have a lot of experience designing power systems and goes through a whole boatload of testing.
And while you can keep them inside just keep in mind if something goes wrong they are closer to you and they burn HOT. Again not something that cant be overcome but im skeptical on the practicality.
I love new tech but lithium batterys make me leery. But you asked for opinions and mine is that they can work but there are better solutions such as a generator with a low voltage auto start wired in for example. It can be done for a few hundred bucks and those small hondas are nearly silent compared to some APUs ive seen.
I looked into it and got $3400 each price and only warranty was 1 year So i did something different
These were the lithium batteries talked to someone named DaveLast edited: Apr 1, 2021
Reason for edit: Incomplete
LiFePo or LFP batteries are the answer, they can be had for $300 per 200 amp hour battery. Expensive but they'll last about 10 years under normal use.
More stable and more temperature stable
Longer life cycle
Safer (less likely to self ignite under charge or quick discharge)
14% Lower energy density than normal lithium ion (ie: phone and tool batteries)
Voltage is only 3.2v per cell as opposed to 3.7
Lithium iron phosphate battery - Wikipedia
One reason why these batteries don’t last in these apus is they are drained past their no return limits in other words past their depth of discharge limit of 50%.
on top of this, they are bulk charged too quickly, so the life of the batteries are limited.
Everyone jumps on the agm batteries wagon but they are just the same with the same limits.
the best solution is to get a good old Diesel engine apu
setup the charging system for the batteries that include a desulfurization unit with a computerized controlled regulator.
My brother has a 40 foot Searay cruiser he has built a battery bank in of 6 volt golf cart batteries.
He uses it to run the a/c unit for 12 hours at night when they anchor up away from shore power. Been with that set up for 35 years .
The golf cart batteries have been the go- to for people in the sailing community for decades who want electricity for refrigeration and such.
I'll ask him which brand as I want to build a system for my truck also.