DogDipstick said:
Yes, I do not discount building with good 21700 cells, for someone can build a 50Ah pack where my 25Ah pack fits.... and still be " strong enuf, long lasting, and reliable, with excellent energy density... "
But is the cost of a 50Ah 2170 Grade A pack
a fair comparison to Battery Hookup salvaged EV module Grade B 25Ah build that still has good usable life ? What's the cost differential ??
DogDipstick said:
Anything reasonable ebike size ( read, legal, as an ebike) really could use smaller cells, with a better energy density, that would take you father. I drain drain my 15Ah ( old, recently replaced, much older cell, 165wh/kG cell.. ) pack in 13 miles in 15 min. I would do this two or three times a day with only 1.2kWh capacity on my QS motor. ~100A load.
What about a 1st time KIS 12S2P 16Ah DIY pouch build (20A Controller and 350W hub) with these salavged cells from Battery Hookup ...
SPIM08HP 3.7V 16AH - THE BEST DIY VALUE! https://batteryhookup.com/products/2x-spim08hp-3-7v-8ah-cells-with-threaded-insert?pr_prod_strat=copurchase&pr_rec_id=0015a724f&pr_rec_pid=5823231361186&pr_ref_pid=5611830968482&pr_seq=uniform. Would likely involve the least amount of labor intensive effort of the EV module choices at BH (12 for $102 plus extras).
Less labor intensive DIY than a 12s, 13s or 14s DIY spot-welded build using Grade A Lishen LR2170SA (4000mAh 12A) cells ($3.50 in quantity).
CS was budgeting $170 for that EV pouch module, but only 5Ah as 1p, and not interested in 2p mod. Salvaged EV modules, even though Grade B, can still have a second life as a powerful e-bike battery ... room enuf permitting. With 2170s he'd need to invest in spot-welding equipment, accessories, etc.
Of the e-bike builds in BHs Customer Project Builds Blog the
SPIM08HP cells seemed to be popular choice (easy peasy) compared to the more time consuming DIY spot-welded build.
16s2p battery pack for an ebike using Battery Hookup's
SPIM08HP cells ...
https://batteryhookup.com/pages/customer-projects
14s1p 8ah battery upgrade for a electric pit bike using BH's
SPIM08HP cells
https://batteryhookup.com/products/spim08hp-3-7v-8ah-200a-lithium-ion-w-cell-holder?pr_prod_strat=copurchase&pr_rec_id=4cafd1c48&pr_rec_pid=4863652692100&pr_ref_pid=5823231361186&pr_seq=uniform
Like with all BH salvaged cells (Grade B) pre-testing is mandatory. Likely that a few cells may lack sufficient capacity. Maybe 10% don't pass pre-test so order extra EV pouches ...
https://www.youtube.com/watch?v=0nGUpzEPfl4
Being
CS had budgeted $170 for the other EV module would it be a good idea to buy at least 5 additional
SPIM08HP cells just in case? For example down the road he may find out one or more of the cells is underperforming and should be replaced or some didn't pass pre-testing.
ONE QUESTION: Spec says:
"Recommend Continuous Discharge Rate 400A" So what if the routine
average drain is 10amp for say: 12s2p, 13s2p or 14s2p with MCD only 20 amps and say only 20-30 percent of the time ??
(2-8Ah paralleled cells (16Ah) in each $8.50 enclosure)