Safest ways to use Li Ion

[slomobile]

Im gonna start by saying that most of us on this forum probably ought not mess with Li Ion in our chairs. Because they can catch fire.
I know that. Im accepting the risk. Im able to feel leg burns and get off.

But these are cheap and the right size and capacity for what I want. Heater/fan provisions. I like the steel case like a saddle between my legs. I guess Ill start calling it the Chariot. Chairiot? ChaiRiot? Chair Idiot? Its like an electric frame runner.

https://batteryhookup.com/products/48v- ... wer-module

What do yall think of these? Im a bit nervous about the clearance between bus bar exit and steel case. 6.6kw Charger? BMS or cell monitor? Logger?

Any opinion at all that strikes you about these pouch modules?

[Burgerman]

2000 cycles to 80% with 100% DOD
under normal temperature

Not in a month of sundays. The only cells that can do that are LFP ones. So what use are the rest of his figures?

Lithium ion at 100 percent discharge give around 300 to 500 cycles. Esp the ones designed as high current high C rate. And you dont know how "used" they are. 1 bad cucle on one cell isnt like nickel, or lead, it does real damage. So who knows what you will get. Other than that and if you dont care then no problem. Theres enough there for a nice mushroom cloud where you house was... BMS work better on lithium ion, but they still have a load of problematic cutouts and so as it says, run the load direct and not via a bms. Use that only for charging.

[shirley_hkg]

9x138x190=235,980 (3.7V-9ah)

14x105x300=441,000 (3.7V-71ah)

What cell is that has such a low energy density ?

[Burgerman]

He says he doesent care how bad the energy density is. We already had this discussion with the last cells he was looking at.

[slomobile]

He says he doesent care how bad the energy density is. We already had this discussion with the last cells he was looking at.

Correct. Plenty of space, long wheelbase 4wd. These units were used as cold weather backup starter batteries for diesel generators. They have heater provisions in the case, so can be charged in below 0 weather like LTO. I can get both LTO and these shipped on the same pallet and compare head to head if I win the lottery.

I'm thinking this might be able to sit outside waiting for me, always charged with solar panels as a shade.
Solar panels just arrived https://www.amazon.com/dp/B0CX1FSQX7
Those are enough to run the well pump during a power outage. I think I can keep it parked right there at the well head next to the driveway and back door.
The panels are transparent between cells letting a little light through.

Was thinking of using this all in one charge controller/mppt wired up to the J1772 plug. https://www.electriccarpartscompany.com ... controller

This is all kind of evolving based on what kind of deals I can get and what I can afford at any moment rather than sticking to my original plan. But it is coming together bit by bit.

300 to 500 cycles is Lead territory, and these are cheaper than lead. So I think I'm ok with that as an experiment. But I'm still looking at LTO as an intermediate battery. Use solar to charge LTO pack, and LTO pack to charge lead, these LiIon, run the well pump, or whatever.

[Burgerman]

If you dont care about energy density, which is the reason we use lithium in the first place then why not use lead. With a lead system sized correctly then a 10 year lifespan is quite possible. No heater needed. And unlike lithium which hates to be stored full, lead works best that way as a standby battery.

[slomobile]

Self discharge, total weight for portability without injury, and cost. I'm currently using an interstate deep cycle ($265) and a 50 w 12v panel($100) for lighting, phone charging, freezer inverter when the power goes out. 48v LiIon ($200) and 400w solar ($250) compares favorably. I'll keep both. 48v up by the house, 12v on the garage.

Not much thought went into theses 48v LiIon besides "that sounds cheap, and powerful enough, and it is shaped kind of like a saddle."