18650 fire cases & 18650 vs 21700 comparison
- Thread starter batteryGOLD
- Start date
eMark
100 kW
Not always ...
13s4p = 52 18650 30Q 3000mAh 15A cells - 12Ah capacity ... $286 ... Samsung 30Q 18650 3000mAh 15A
13s3p = 39 21700 BAK 5000mAh 15A cells - 15Ah capacity .. $225 ... BAK 21700 5000mAh 15A Battery (N21700CG)
You can cause just as big of an explosion by accidently overcharging an 18650 battery with 52 cells as a 21700 battery with 39 cells.
The newer 30Q 6-T or 30Q 6-150-T aren't as plagued by high self-discharge as were the 30Q 136 & 141.
batteryGOLD
100 W
30Q is trustable? maybe yes/no --> yno, bacauseee I've seen many cases(+100 in 1year time frame) of 30Q leaking voltage, used at some onewhells's (onehell or onepleasure) plus a 10KW ebike battery 10P20S 30Q and arround 30% cells with problems.. some voltage leak (soo battery useless..)
200cells tested and about 30% considered trash and other 70% maybe OK..
70% of 2 hundered is 140cells maybe ok
the best way to test all new/used 30Q is to charge those at 4,23V and let those rest for a week or more
than after rest time, you measure those. if all keep aprox initial voltage (down to 4,15V-4,10V) is acceptable after one week
but some could go to 4.05V , 3.79V , 3,45V . soo carefull with those.. maybe you'r lucky and it never happens
should I built a new battery using 30Q cells or should I quit 30Q? (should I stay or should I go Clash song..)
and about BAK, thats a new emerging brand. seems promising lithium tech.. but for trusted brand, any product needs at some years of customers usage and good feedback. Anyone tested those BAK?? please report results
*outoftopic*
would you buy a original class A limousine Mercedes or a identical CN copy, almost "same performance" at 1/3 of price? driving a "Mercedes class A limousine" copy at 1/3 of price with same look Would you accept that?
Same happens with MATE ebike and engwe ebike (almost identical but 1/3 price difference )
personally, I prefer the most expensive stuff with tha best look & style
Hillhater
100 TW
That would depend on how much you could afford ?
batteryGOLD
100 W
batteryGOLD
100 W
x50 difference: Is better a 20cents 1L water bottle or a special water 1L 10euro?
x100 difference: Is better a $100 chocolate tablet or a $1 chocolate tablet?
x5000 difference: Is better a $2 wine bottle or a $10.000 wine bottle? (taste & alcohol effect variables)
personally, I prefer tha $100 chocolate tablet (a box with 50units = $5000) and tha 10eur 1L water bottle. but thats just me. so final pack cost will be $5000 and 10euro plus expensive toilet paper ($50 per roll?! for chocolate after digest..)
x100 difference: Is better a $100 chocolate tablet or a $1 chocolate tablet?
x5000 difference: Is better a $2 wine bottle or a $10.000 wine bottle? (taste & alcohol effect variables)
personally, I prefer tha $100 chocolate tablet (a box with 50units = $5000) and tha 10eur 1L water bottle. but thats just me. so final pack cost will be $5000 and 10euro plus expensive toilet paper ($50 per roll?! for chocolate after digest..)
eMark
100 kW
Were the 30Q cells you reference (tested) and those in that "10P20S" 30Q "136" or "141" cells?
Have you yet tested any 30Q 6-T or 6-150-T cells using your following test parameter ...
"charge those at 4,23V and let those rest for a week or more
than after rest time, you measure those. if all keep aprox initial voltage (down to 4,15V-4,10V) is acceptable after one week."
According to my initial test both the 6-T and 6-150-T are acceptable, so far. Will know more as more cycles accumulate this year and when disassembling experimental pack for further testing this winter.
NOTE: Although IMR shows a "141" (30Q cell) they may no longer stock 141. I received 6-T in 11/21 and 6-150-T in 1/23. At the time i was rather upset, but IMR would never tell me why they shipped me "6-T" in 11/21 instead of "141". Now i'm glad they sent me both "6-T"(11/21) and "6-150-T"(1/23) instead of "141" cells ...
Samsung 30Q 18650 3000mAh 15A Battery
With an energy capacity of 3,000 mAh and an uninterrupted maximum continuous discharge/drain rating of 15 amps, this cell delivers exceptional performance. Its remarkable cycle life is another crucial factor to consider in your purchase decision, alongside its other features. This cell runs with...
eMark
100 kW
Also see posts (30Q) by Pajda cz at ... BAK released the new N21700CD 5300mah battery
batteryGOLD
100 W
series are 136
soo, seem's to be a potential problem
this cells should be considered half current 7,5A instead of 15A
passing 15A on it, maybe drives it crazy sooner..
eMark
100 kW
Whenever marketing lingo (IMO) claims say 15A Maximum Continuous Discharge with 500 cycles possible it is so much BS (IMO).series are 136
soo, seem's to be a potential problem
this cells should be considered half current 7,5A instead of 15A
passing 15A on it, maybe drives it crazy sooner..
The continuous discharge rating of 15A for the BAK 21700 in actuality should be 10A for cycle life longevity. The following review was by Mooch (2021) ... published in reddit and elsewhere ... Bench Test Results: BAK N21700CG-50 – 15A 5000mAh 21700…decent performer, equal to Samsung 50E3
"This BAK [21700] performs a little better than the Molicel M50A (but the BAK runs a few degrees hotter) and about the same as the Samsung 50E3. It doesn’t perform as well as the Samsung 50S but that cell is very expensive and hard to find.
The datasheet rates this cell at 15A but notes that this affects cycle life. I recommend staying below 10A to reduce risk, increase overall cell life, and increase performance.
The two cells I tested delivered 4987mAh and 5020mAh. This is decent consistency for a cell from one of the large, established China factories. Both cells tested above their 4900mAh minimum capacity rating and essentially at their 5000mAh typical rating.
Two cells were donated for testing by 18650BatteryStore. Thank you!"
