eMark
100 kW
A couple reasons i went with 30Q 15A even with my "conservative" etriking ...
1) With it's low IR wanted to see if i could get 500 cycles from my 10S3P 30Q 141 pack over 3-4 years by charging to only 4.1V and discharging to only 3.5V. Hopefully, maintaining enough capacity for a 5-6 mile round trip with minimal pedal assist through 500 cycles.
(2) Also hoping my TLC "conservative" (non-raw performance) would negate any eventual high self-discharge tendency that has been reported by others using the 30Q "136" cells.
My 10S3P is wired with two 5S balance leads for cell logger alarms. When split into two 5S3P sub-packs for bottom balancing before straight charging the two 5S3P packs paralleled together for 1.5A (0.5C) straight charging. Then reconnecting again as one 10S3P 30Q 141 pack.
This was the pack's first winter rest having accumulated 170 charge/discharge cycles from mid-March thru mid-November of 2020. So, I'd hoped that my TLC would've yielded favorable good news when recently testing the 30Q 141 cells for any self-discharge.
On January 2nd I charged (balanced) all 30 cells with each cell at 3.75V. Sadly my "conservative" etriking with the newer (2019) Samsung 30Q "141" cells still resulted in some of the 30Q "141" cells suffering from self-discharge. Five of the cells suffered from what i'd consider high self-discharge. This self-discharge was first evident after three days on 1/5/21 then more so on 1/10/21, and even more so on 1/15/21. Of the thirty 10S3P Samsung 30Q 141 cells twenty-one still remained at 3.74-3.75V on 1/15/21. However, nine of the thirty cells suffered from self-discharge ranging from 3.72V to as low as 3.43V on 1/15/21. Following are the self-discharge voltages of nine cells, five of which i'd consider high self-discharge.
5S1 Sub-Pack
1s1p/3.66V; 2s3p/3.43V; 4s2p/3.70V
5S2 Sub-Pack
1s1p/3.72V; 1s2p/3.68V; 4s2p/3.72V; 5s2p/3.70V; 3s3p/3.62V; 5s3p/3.57V
On average i recharged my 10S3P 30Q 141 pack every 1½ days so any self-discharge wasn't apparent or problematic for my etriking enjoyment.
1) With it's low IR wanted to see if i could get 500 cycles from my 10S3P 30Q 141 pack over 3-4 years by charging to only 4.1V and discharging to only 3.5V. Hopefully, maintaining enough capacity for a 5-6 mile round trip with minimal pedal assist through 500 cycles.
(2) Also hoping my TLC "conservative" (non-raw performance) would negate any eventual high self-discharge tendency that has been reported by others using the 30Q "136" cells.
My 10S3P is wired with two 5S balance leads for cell logger alarms. When split into two 5S3P sub-packs for bottom balancing before straight charging the two 5S3P packs paralleled together for 1.5A (0.5C) straight charging. Then reconnecting again as one 10S3P 30Q 141 pack.
This was the pack's first winter rest having accumulated 170 charge/discharge cycles from mid-March thru mid-November of 2020. So, I'd hoped that my TLC would've yielded favorable good news when recently testing the 30Q 141 cells for any self-discharge.
On January 2nd I charged (balanced) all 30 cells with each cell at 3.75V. Sadly my "conservative" etriking with the newer (2019) Samsung 30Q "141" cells still resulted in some of the 30Q "141" cells suffering from self-discharge. Five of the cells suffered from what i'd consider high self-discharge. This self-discharge was first evident after three days on 1/5/21 then more so on 1/10/21, and even more so on 1/15/21. Of the thirty 10S3P Samsung 30Q 141 cells twenty-one still remained at 3.74-3.75V on 1/15/21. However, nine of the thirty cells suffered from self-discharge ranging from 3.72V to as low as 3.43V on 1/15/21. Following are the self-discharge voltages of nine cells, five of which i'd consider high self-discharge.
5S1 Sub-Pack
1s1p/3.66V; 2s3p/3.43V; 4s2p/3.70V
5S2 Sub-Pack
1s1p/3.72V; 1s2p/3.68V; 4s2p/3.72V; 5s2p/3.70V; 3s3p/3.62V; 5s3p/3.57V
On average i recharged my 10S3P 30Q 141 pack every 1½ days so any self-discharge wasn't apparent or problematic for my etriking enjoyment.