Mixed 18650 from batteryhookup

[lucasd05]

Do folks have any opinions/experience related to the mixed 10lb packs @ $17 from batteryhookup.com?

That works out to 29¢ per cell (including shipping to my address). That's pretty much the lowest price I've seen, which automatically makes me skeptical - - but this review of one of their previous mixed boxes looks fairly positive, though that was specifically medical packs whereas the current listing seems to be a total grab bag. I'm not sure if that makes a difference.

So... any thoughts or experience with these mixed bags of batteries? Are their IR and mAh ratings too varied? Or does the low price mean properly distributed Frankenstein packs are worth a try?

 

[OffGridInTheCity]

Over time, I found better results (packs in series don't need much capacity tweaking / stay balanced easily) by making each of my 14s batteries with the same cell type or at least even numbers of each type in each pack.

If you can buy enough so that each XsYP battery is the same cell type... OR you can evenly distribute the similar counts/capacity among the Xs packs... then it could work out fine.

 

[lucasd05]

Hmm, yeah. I see various people saying they get the most consistent, balanced packs when using all one variety of cell. That makes sense, as they'd all behave similarly.

I guess the strategy for using this kind of assortment effectively would have to be figured out once you had them in front of you and could see what sort of distribution there was. Batteries are just like anything I guess - you spend money or you spend time.

 

[OffGridInTheCity]

Hmm, yeah. I see various people saying they get the most consistent, balanced packs when using all one variety of cell. That makes sense, as they'd all behave similarly.

I guess the strategy for using this kind of assortment effectively would have to be figured out once you had them in front of you and could see what sort of distribution there was. Batteries are just like anything I guess - you spend money or you spend time.

Yes. But also there's a question of what the battery does. An EV battery vs powerwall vs UPS vs other - have different operating requirements.

For example, because I'm off-grid and heavily ATS'ed, I have a set of 3000w APC UPSs - each with their own dual 7s7p batteries. I was thinking of using all my left-overs (1000+ cells) to build a common 14sXXp to service all 3 of them. The 'battery' would basically just sit there at 3.94v all day.

 

[lucasd05]

Sure, different use cases have different demands.

For instance, I see a bunch of modem packs for sale that are primarily LGDAS31865 cells, and I've seen a few people on here say to steer clear of those due to relatively higher IR values. I've seen the same said about with laptop cells due to their relatively low C rates compared to other types. Still, those two (laptop and modem packs) seem to be some of the most reasonably priced and easily sourced salvage packs for cells, and I'm debating whether they'd really be that bad in a power wall where they're never going to see high discharge rates. -- "High" being a very relative term, of course.