New idea. Wait for it to be edited.
I have two more modules and can make two 4p12 sets.
All my work on this one gone, but water over the dam. I need to make a useable battery out of what I have.
120ah total 88v nominal.
Two of these:
12.5 x 15 x 8
End to end 30 x 12.5 x 8 total.
I used three 16s Chevy spark batteries that I converted to 8s and then hooked them up in series to create a 24s pack. I had to remove the center seat support bracket to make them fit. In my eyes the bracket isnât needed anyways. The seat frame is quite stout.
David, do you have a picture of your battery setup and fitment in your Think?
The sdi pack will fit if someone had the ability to remove the side rails.
Total width of battery is 14.5" but cell total width is ~13.6".
Do you fellas have any recommendations on a simple BMS or similar? I just want to be able to balance and monitor my LifePo4 cells.
Or should I just balance them once and just use them, periodically checking them?
Due to constant voltage output aggressive active balancing doesnât work well.
Shunt balancing over 3.6 volt is what I use. Discrete balancers, one on each cell. What is center to center spacing of your cells?
They are ~3 7/16â, or ~88mm
Let me see what I have. Picture from battery space. Mine are higher power and 1/2 price.
Great! I would need 24 minimum.
Should have enough of these with copper extenders to make them fit a wide range of cells.
My picture.
I love these for balancing lifepo4. Green indicator shows they are connected and working. When cell reaches 3.65v red led illuminates and draws 500ma current. Remains on after charging to bring any rogue cells down to 3.6v.
Iâll check quantity tomorrow. $6 each.
Perfect, thank you. Let me know and I will send payment.
Need your street address.
Thank you,Inwo, for the balancers. I got them installed and they work perfect for what I needed!
With these batteries, I even had room to have a dedicated 12v battery for accessories.
Very clean! So with balances, no need for BMS? Which charger are you using?
I wonât be using a BMS. I balanced them in parallel prior to install & will check them periodically (probably twice a year).
I charge them with a DetlaQ (model 922-7254) that has lithium algorithms installed. The cutoff/full charge voltage is set to 87.6v total.
It has been a fun little project so far.
Thatâs what I do, and recommend. It will not replace a bms with a lvc and hvc, but lfp are pretty stable and safe.
The kiss of these discrete balancers is what makes lfp attractive. IMO
ps.
IMHO
Balancing lfp any place except âover chargedâ is a fools errand. A balancer can only attempt to keep voltages the same. Lfp are pretty much the same volts through their useful range.
