I have 96x2=192 cells
LiFePO4 26650 Battery Assumptions
Specification | Value |
---|---|
Nominal Voltage | 3.2v |
Max Voltage | 3.6v |
Cutoff Voltage | 2.0v |
Capacity | 2300mAh |
Specification | Value |
---|---|
Nominal Voltage (4 x 3.2v) | 12.8v |
Max Voltage (4 x 3.6v) | 14.4v |
Min Voltage (4 x 2.0v) | 8v |
Cells in Series for Voltage | 4 |
Parallel Cells to Get Capacity 48Ah/2.0Ah | 24 |
Total Cells Required | 96 |
Dimensions (W x L x H) 1 cell: 26mm x 65mm pack size: 26*4 x 26*24 x 65 | 104mm x 624mm x 65mm |
Picked up a couple of BAE UPS battery packs.
Spec | Values |
---|---|
Make | BAE |
Model | 235C9387G1 |
Dimensions (WxLxH) | 31" X 6.5" X 3" |
Weight | 19.55 lbs |
Voltage | 40V |
Configuration | 12S8P 12*3.2v = 38.4v |
Current | 2250A |
Watt Hours | 736 wH |
Equivalent Ah for 12v | =P/V = 736/12 = 61Ah |
Battery | 26650 LiFePO4 |
Info | https://secondlifestorage.com/showthread.php?tid=5451 |
Video - Teardown | https://www.youtube.com/watch?v=AG36QB1WkuY |
Cells A123
Spec | Value |
---|---|
Model | ANR 26650 M1B |
Chemistry | LiFePO4 |
Dimensions(DxH) | 26mm(1.0") x 65.15 mm(2.6") |
Max Current | 50A |
Nominal Voltage | 3.25V +/- 0.05V Nominal, 3.2V Average |
Nominal Capacity | 2500 mAh (at 0.2C rate, 3.65 +/-0.05V cut-off) |
Charging current |
|
Temperature Range |
|
Image |
Observations:
Battery Configuration | Estimated Capacity (~2Ah/cell) |
---|---|
4S8P | =2Ah * 8 = 16Ah |
4S24P | =2Ah * 24 = 48Ah |
Original Battery Confguration - 12S8P
New Configuration - 4S8P x 3
Could use 3 BMSs for this configuration or just one.
Someone else's solution
The rated capacity of these batteries is 2500 mAh. It appears that the average capacity seems to be around: 1186 mAh.
|
|
812 818 902 917 935 952 964 1017 1083 1087 1092 1095 1101 1109 1111 1119 1163 1187 1203 1213 1236 1255 1262 1277 1287 1332 1333 1431 1467 1478 1828 1891 |
Pack | Original Capacity | Starting Voltage | Final Voltage | Capacity (mAh) | % Capacity | ~Capacity/Cell | Notes |
---|---|---|---|---|---|---|---|
2 | 20Ah | 14.4 (3.6v/cell) | 8v | 10156 | 51% | 1270 mAh | |
3 | 20Ah | 14.4 (3.6v/cell) | 8v | 10926 | 55% | 1366 mAh | Could the battery be overcharged? |
3 | 8v | 9791 | 49% | 1224 mAh | |||
3 | 8.49v | 7727 | 39% | 965 mAh | BMS Added. | ||
3 | 8.55v | 6315 | 32% | 789 mAh | Charging via power may be the issue? Discovered that I had connected the cell voltage connectors in the wrong order. | ||
3 | 13.91 (3.48/cell) | 11.27? | 8123 | Cells balanced before test to: 3.52, 3.58, 3.31, 3.32 BMS is attached. Stopped at 11.27v because 1 cell voltage had dropped too low. Needs to be better balanced or taken apart and re-purposed. | |||
4 | B-: 13.7 C-: 13.6 P-: 12.57 | BMS Attached. Charged with C- using Car Lion Charger Cells: 3.46, 3.43, 3.41, 3.42 @9500mAh: 12.5V on all -Terminals Is there a voltage regulator on the output? |
.
Notes:
Battery pack #1
Battery Pack #3:
Size: 87*35*8 (MM)
Notes:
Example 4S20P
Packaged in 4S8P
Installed in a 50 Caliber Ammo Box (Inside Dimensions: 5.8" L x 11" W x 7.2" H)
I bought Plano 50 Cal Ammo Box, Black
Interior dimensions: 11.25" x 5.5" x 7" (Slightly thinner by 0.3" - Doh!)
Reference | URL |
---|---|
Buying Used Batteries | https://batteryhookup.com/ |
A123 Spec | https://www.batteryspace.com/a123-lifepo4-26650-rechargeable-cell-3-3v-2500-mah-50a-rate-8-25wh-anr26650m1b---un38-3-passed-and-iec-listed.aspx |
Battery Pack Calculator | http://repackr.com/ |
LiFePower LiFePO4 Batteries | https://www.sawtechnology.com/solarengine-battery |
Building a pack in Ammo Boxes | https://www.youtube.com/watch?v=9CwnX9tovAM |