some of the new lithium chemistries that perform great are unstable/dangerous
Generally speaking, the ones that have the highest power density (good where space/weight saving are top priority) are the more unstable and potentially dangerous ones. I lit my yard on fire a few years back shooting at an old laptop when I hit the battery pack in that, the flammable type lithium cells are definitely no joke and I'd never consider something like that in a car.
When you say 5S or 6S, does that mean a 5 cell bank or 6 cell bank?
Shorthand when we discuss lithium cell banks. S = Series, P = Parallel.
The Lishen cells are rated at 15C/50C. 15C being the maximum recommended continuous pull (270A), and 50C being the absolute maximum rated draw (900A).
My guy in China says those cells are legit, but I think if you look at the ratings you'll see best cycle life and overall performance more around 3 and 10C respectively. For the small cost/weight/space, why cheap out and try to redline these? Mind you, I'm planning on doing some torture testing on my Toshiba cells whenever I get a chance to get them built up and do testing, but barring 3 second burp only application I'm not trying to skimp on a bank in a vehicle.
I wouldn't get hung up on the rail voltage thing in those "Smart" amps. It's the same thing JL has done for decades now, more or less, and they perform fine for every day music applications.
Good you bought a house already, they're not getting cheaper probably ever.
Although, as previously stated, they can probably be run without a balancing circuit for a long time. Even if I only got another year of lifespan, I still think it would be worth a $40 balancing circuit.
For what, a 400$ battery bank? Bear in mind you're only buying/building bussing once. You'd spend 400$ on parts store AGMs to run a 3K amp (and not nearly as well) and be happy to get 4 years out of them before they're only worth the core return. Give it a whirl, but I'd say if you're that concerned just take them out a couple times a year and replace any cells that aren't within spec of the others. I suppose only time will tell what's best and certainly if you get a dud cell it'll cause trouble, but these are built to take a good bit of abuse and last a very long time. Do give it a whirl and report back though. I was considering adding something when I got mine but at the time there was no off-the-shelf solution for this sort of thing and honestly with the amount of current we're running in and out of these I'm not really sure it's going to matter much either way for our applications. If I were doing a big solar bank for the house or something, sure I'd be looking at balancing but you'd be dealing with low enough current that charging and discharging could all be done through some sort of BMS system.
