RE: Borderline Capacity Finding - Interim - 272AH (0.5C) and 276 AH (0.3C)
Leaning toward "Accepting" this as "Close Enough" - even though part of me think 1C 280AH factory spec should be met.
HARDWARE: EVE 280 AH - x8 as 24V system.
-Stated as A - and factory matched/binned set.
-Stated as 280AH Model N x 8 in sales order. Actual received goods: 2x Type 66 (280 w/o N) and 6x Type 71 (280 w/ N)
-Charge BMS600T base with DCC_300 Common DCC
TEST PARAMETER
1. Original Top-Balanced 3.65V parallel set until < 1 A consumed
2. 1-Hour Settle Time given - running down first cell to hit 2.5V as endpoint.
3. 0.5C Test
A) 2x Electric Heater and Tesla charging at 11A/120V
0.3C Test
B) Electric heaters only
4. After several fails to reach 280AH - when LVD triggered at 2.5, some other cells at 2.6 - 2.7 range.
5. Terminals and Busbars: Re-Sanded (2000 grit), Re-Cleaned Isopropyl 70%. Minor amount of NoAlox/barely visible.
6. DMM vs. Chargery V variable w/o load - 3 - 7 mV observed. Chargery notes IR < 0.1mohm (0.7 or 0.8 for each cell).
7. Repeats Top Balance and terminal cleaning to see if it would improve yield - and did so only modestly.
8. Capacity rating measured with VICTRON 500A BT Shunt and Chargery Shunt. (Chargery 1st in line). Victron shows slightly lower figures than Chargery.
The Top-of-Mind item for me is to ORDER Chargery Power cable and draw external power from full battery instead of lead 1 - or with a separate external LiFEPO4 system. Wondering if the last 3% is the 2.5 vs 2.6 window being lost from chargery pulling power from cell 1.
Good news being - I think this is close enough capacity wise.
Bad news being - I feel jaded about ordering and paying for LF280N and getting 6x N and 2 x LF280 (non-N) with what appear to be different manufacture dates. Still wondering if the Type 66 vs 71 will manifest in 1 - 2 years as "runner" or higher IR.
Plenty of photos on request. Either way - happy to have 7.5kWH of hobbying capacity.
AND KUDOS to this Board - I greatly appreciate the wealth of knowledge and experience shared!
Leaning toward "Accepting" this as "Close Enough" - even though part of me think 1C 280AH factory spec should be met.
HARDWARE: EVE 280 AH - x8 as 24V system.
-Stated as A - and factory matched/binned set.
-Stated as 280AH Model N x 8 in sales order. Actual received goods: 2x Type 66 (280 w/o N) and 6x Type 71 (280 w/ N)
-Charge BMS600T base with DCC_300 Common DCC
TEST PARAMETER
1. Original Top-Balanced 3.65V parallel set until < 1 A consumed
2. 1-Hour Settle Time given - running down first cell to hit 2.5V as endpoint.
3. 0.5C Test
A) 2x Electric Heater and Tesla charging at 11A/120V
0.3C Test
B) Electric heaters only
4. After several fails to reach 280AH - when LVD triggered at 2.5, some other cells at 2.6 - 2.7 range.
5. Terminals and Busbars: Re-Sanded (2000 grit), Re-Cleaned Isopropyl 70%. Minor amount of NoAlox/barely visible.
6. DMM vs. Chargery V variable w/o load - 3 - 7 mV observed. Chargery notes IR < 0.1mohm (0.7 or 0.8 for each cell).
7. Repeats Top Balance and terminal cleaning to see if it would improve yield - and did so only modestly.
8. Capacity rating measured with VICTRON 500A BT Shunt and Chargery Shunt. (Chargery 1st in line). Victron shows slightly lower figures than Chargery.
The Top-of-Mind item for me is to ORDER Chargery Power cable and draw external power from full battery instead of lead 1 - or with a separate external LiFEPO4 system. Wondering if the last 3% is the 2.5 vs 2.6 window being lost from chargery pulling power from cell 1.
Good news being - I think this is close enough capacity wise.
Bad news being - I feel jaded about ordering and paying for LF280N and getting 6x N and 2 x LF280 (non-N) with what appear to be different manufacture dates. Still wondering if the Type 66 vs 71 will manifest in 1 - 2 years as "runner" or higher IR.
Plenty of photos on request. Either way - happy to have 7.5kWH of hobbying capacity.
AND KUDOS to this Board - I greatly appreciate the wealth of knowledge and experience shared!
