K2 battery

[ESR_RSE]

Cut open two K2B24V10EB and swapping out the BMS into four 12V LiFePO4 packs. I repacked it to fit a GoPed but the battery cuts out. Cells will do 36A but BMS set to 24A -> changing to 30A BMS.

 

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Trying out some cheap 30A 4S BMS boards.



Going to run some testing before wrapping in foam and shrink wrapping the entire thing. Cells can do 86A pulse but not sure what would happen to the board/wiring. BMS info claims it can do 56A pulse. Hard to fit big wires on the pads & went with 13gauge equivalent on one and then did get 10gauge on the 2nd one.

Not exactly cost effective but this was before I had a kWeld or knew anything about battery construction. The K2 package seem well made since they have these huge welded Nickel plates on the 8S3P setup. Could of been a "slam dunk" if the stock K2 BMS supported the amp draw of the GoPed ESR controller. If it does not work out then I at least have some useful 12V batts.

 

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Awaiting ANT smart BMS shipment from China and I will have another post about 18650 pack construction. A123 cells, badass.

 

[john61ct]

None of those image links rendered here, app nor browser.

Cut open two K2B24V10EB and swapping out the BMS into four 12V LiFePO4 packs. I repacked it to fit a GoPed but the battery cuts out. Cells will do 36A but BMS set to 24A -> changing to 30A BMS.

When I "shuffled" the cells around to fit 2x SLA size.

Post 2's are fine

 

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Bleh. Probably since I am logged into the other forum it looked fine to me. Fixed.

 

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Finished up w foam and shink wrap. I decided against the heatsink and went with a thick thermal pad.

Just need to see if can really put out the decent amps.

 

[sharinginfos]

Finished up w foam and shink wrap. I decided against the heatsink and went with a thick thermal pad.

Just need to see if can really put out the decent amps.

hi could you please share with me the specs of the bms, im looking into placing 3 batteries in parallel for a 24v setup

 

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I used this board. It works better than the K2 one that was included but still cannot handle the instant amp request of the ESR controller. (which I hear can be 100A+)

https://www.amazon.com/gp/product/B07CB14RT1

• Maximum operating current: 30A
• Maximum instantaneous current: 56A
• Over charge voltage range: 3.75V±0.05V
• Quiescent current: less than 30uA
• Internal resistance: less than 20mΩ
• Charging voltage: 14.8V-16V
• Charging current: 20A Max
• Working temperature: -40 - +50°C
• Storage conditions: -40 - +80°C
• Short-circuit protection: Trigger condition: External load shorted. Release condition: disconnect the load.
• Size: 56*48*4.0mm

Wired the packs in series and then in parallel for ~24v & ~10Ah.

Here is the individual cell:

 

[ESR_RSE]

I originally used the K2 BMS but later swapped to these 12V BMS since the max operating current was higher.

Let me know if you find a better 24V with even better specs to the K2 cells.