WA: Good Condition 10S8P Split (20S8P Series) Samsung 25R Battery Packs - $250


100 W
May 11, 2020
9/25 Update: Realized I didn't include a capacity estimate. I'd guess a truncated 4.15V to 3.25V cycle @ 1A discharge would be over 80% so at least 16Ah. Price lowered to $1.56/cell vs $3.85 new, motivated to sell. I should be able to run a 1A discharge on my 3010B charger to show this cycle capacity on request, just let me know. Sad to see them just sit around, but I don't have any projects that need them.

These packs have been getting zero use lately which seems a shame. Lots of life left
(a link to an unused 25R cell I tested recently from same 2015 batch showing impressive negligible calendar aging effect). I prefer a local sale (Pierce County) if anyone around is interested in these for a project, but will ship if you want to cover the shipping cost.

25R 10S8P Packs.JPG

Now for the overly-detailed specification/descriptions.

Physical Description:
• 2X 10S8P in corresponding ABS 18650 battery holders
• Outermost dimensions measure 8.75” width X 7.25” height X 2.75” depth for each pack
◦ Made to easily fit inside Kilo-Watt bag (shown, not for sale)
• Main pack fuse is Littlefuse FK3 MAXI-style 80V, 50A rated
• Weight is a little less than 10 lb per pack

25R Spot Welds.JPG

Assembly Details:

• Packs protected/wrapped with thick 1mm heat-shrink
• Pure nickel H-strips with 7mm X .15mm interconnects were used for series/parallel connections
◦ 6 spot welds per battery terminal
◦ Paper washers on positive terminals were not used in assembly
• Pre-soldered, equal-length 14 AWG (1 per series path) on both + & - connections join with dual 10 AWG and Anderson PP45 connectors (shown)
◦ 4X 14 AWG feeds 1X 10 AWG
• 22 AWG used for balance leads connect to DB15 adapters for the balance connections
◦ Used with external balancer/charger

25R Charging Setup.jpg

Battery Condition:

• Batteries were purchased brand new February 2015
• Estimated total charge cycles: ~120 to 140 (a count of # of times on the charger not full 4.2-2.5V or even 4.1-3.25V cycles)
• Of these total charge cycles an estimated
◦ ~60% were charged to 4.07V Max SoC,
◦ ~30% to 4.08V,
◦ ~10% to 4.10V
• Controller LVC was set to 65V or 3.25V/cell
◦ Only hit LVC for probably an estimated < 25% of charge cycles/rides as these were all varied route joyrides
• Max Battery current was set at 48A or 6A/cell
• Always stored indoors @ room temp and never with or near a full charge
◦ 100% of all charging occurred right before a ride
• Charged in parallel, used on e-bike in series for 20S8P.
• Packs last used Q1 2021