Test/review of Shockli 6x18650 7.4V 6600mAh

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HKJ
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Test/review of Shockli 6x18650 7.4V 6600mAh

Shockli 6×18650 7.4V 6600mAh
DSC_6462
Official specifications:


  • Rated capacity: 6600mAh
  • Rated voltage: 7.4V
  • Weight: 328g
  • Cable length: 55cm

Shockli%206x18650%207.4V%206600mAh-info
This is a 6 cell bicycle pack.
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DSC_6465 DSC_6466 DSC_6467
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The protection circuit looks like it is checking both cell groups, but without balancing.
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Shockli%206x18650%207.4V%206600mAh-Capacity
Capacity is considerable better than rated. The over current protection will trip at loads much above 5A (This is temperature depend).
The pack was up to about 51° during my test (Measured in the pouch).
Shockli%206x18650%207.4V%206600mAh-CapacityTimeHours
Shockli%206x18650%207.4V%206600mAh-CapacityTime
Shockli%206x18650%207.4V%206600mAh-Energy
Shockli%206x18650%207.4V%206600mAh-PowerLoadTime
The pack can easily drive a 10W load, but 30W is a bit much (25W would probably be fine).
Shockli%206x18650%207.4V%206600mAh-TripCurrent
Shockli%206x18650%207.4V%206600mAh-Charge
Conclusion
The pack works fine, but has a fairly low capacity (4 high capacity cells would give the same performance).
Notes and links
The battery was supplied by Shockli for review.
How is the test done and how to read the charts
How is a protected LiIon battery constructed
More about button top and flat top batteries

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

ferongr
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Is there any charger for these 2S packs you can recommend (outside of a hobby charger)? IIRC you have checked a couple of these in the past and none of these terminated. I don’t feel safe relying on the protection circuit to terminate on cell overvoltage.

HKJ
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ferongr wrote:
Is there any charger for these 2S packs you can recommend (outside of a hobby charger)? IIRC you have checked a couple of these in the past and none of these terminated.

I have not seen one yet.

ferongr wrote:
I don’t feel safe relying on the protection circuit to terminate on cell overvoltage.

They will not apply over voltage to the cells, they will “just” wear the cell down faster.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

ferongr
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I’m somewhat interested in putting a mosfet for termination in the enerpower one, with the gate controlled by the green LED.

ledoman
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HKJ where have you measured voltage, was it at protection circuit output (P+, P-), at cells side (B+, B-) or at connector?
It is strange to get so much more capacity than rated, specialy when brand is not known. At 5A it is obvious cells can stand only low current up to 1A/cell.

HKJ
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ledoman wrote:
HKJ where have you measured voltage, was it at protection circuit output (P+, P-), at cells side (B+, B-) or at connector? It is strange to get so much more capacity than rated, specialy when brand is not known. At 5A it is obvious cells can stand only low current up to 1A/cell.

All measurements are done at the end of my test cable that is plugged into the connector.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

ledoman
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Thanks, this might explain quite big voltage drop at higher currents or you think it is more cells related? Shurely there is some resistance in circuit and cables, still probably not that much.

HKJ
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ledoman wrote:
Thanks, this might explain quite big voltage drop at higher currents or you think it is more cells related? Shurely there is some resistance in circuit and cables, still probably not that much.

There is definitely some voltage drop in cables, connection and protection. I did not analyze exactly how much.

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/

Hobbyfotograaf
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All the bikelight batteries i used failed after time because there is no balancing circuit.
After a couple of months there is such a large unbalance between the two sets of parallel cells that the maximum useable capacity of the battery pack becomes very low.
When i connect such battery pack to the hobbycharger (cells connected directly to the charger) , the capacity gets back to “normal” (i never had a bikelight battery pack that delivered the promised capacity).

ledoman
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This is because you are buying to cheap packs with low quality cells.

Come over to MTBR and see this two threads:
http://forums.mtbr.com/lights-night-riding/battery-thread-2016-beyond-99...
http://forums.mtbr.com/lights-night-riding/quality-8-4v-6800mah-4-x-ncr1...