Supercapacitor Battery Replacement

[Ecky]

For whatever reason, supercapacitors seem to be harder to find now than they were 5 years ago. However, lithium has come a long way. Granted it can still melt down, but LiFePO4 is much less likely to.

I took a chance on some $12usd shipped AliExpress 20Ah cylindrical cells, and assembled a pack out of them. So far, they appear to exceed their rated specifications.

[redpoint5]

Originally Posted by Ecky

I took a chance on some $12usd shipped AliExpress 20Ah cylindrical cells, and assembled a pack out of them. So far, they appear to exceed their rated specifications.

$12 each cell? What is the size, because the biggest I could ever find is 32700 at 7.2Ah. I paid something like $4/cell, but that was before the WuFlu.

Where did the case come from?

The problem I'm having is that the wiring for balance circuits is the opposite polarity of balance leads for external chargers. I have to decide to either wire it for a balance board, or wire it for external charging/cell voltage output, but not both.

I just got a UPS for myself, for Christmas, and am looking to replace the lead acid battery with LiFePO4.

[Ecky]

Originally Posted by redpoint5

$12 each cell? What is the size, because the biggest I could ever find is 32700 at 7.2Ah. I paid something like $4/cell, but that was before the WuFlu.

Where did the case come from?

The problem I'm having is that the wiring for balance circuits is the opposite polarity of balance leads for external chargers. I have to decide to either wire it for a balance board, or wire it for external charging/cell voltage output, but not both.

I just got a UPS for myself, for Christmas, and am looking to replace the lead acid battery with LiFePO4.

Search for "Soshine 40135". I would have gone for the Liitokala cells, which are reputedly legitimate and come with threaded posts, but none of them were available with reasonable shipping to New Zealand. The Soshine cells so far appear legit but you need to use either a (strong) tap welder, or use the cells in a lower current application where it's acceptable to use spring contacts to connect them.

The case is one I'm reusing. I had a powersports battery which failed when I left my Miata with a body shop for a few weeks. They ran it dead and jump started it multiple times, which eventually cooked the cells.

[Ecky]

These are the cells I used:

https://www.aliexpress.com/item/1005...21431802QENEyV

Were I to do it again, I might give these a try, simply for ease of assembly:

https://www.aliexpress.com/item/1005...KRbXKRbO8&mp=1

You may be able to find a better deal on the Liitokala cells. I can't easily see the shipping rate to the US.

[redpoint5]

Originally Posted by Ecky

These are the cells I used:

https://www.aliexpress.com/item/1005...21431802QENEyV

Were I to do it again, I might give these a try, simply for ease of assembly:

https://www.aliexpress.com/item/1005...KRbXKRbO8&mp=1

You may be able to find a better deal on the Liitokala cells. I can't easily see the shipping rate to the US.

Must be new formfactors, as a Brave search says that 32900 are the largest cell sizes available.

The 46135 (25Ah) looks to be the perfect size to replace motorcycle batteries, and the stud posts makes it simple to assemble.

I had no idea there were better options available. I'll have to stock up now before tariffs hit.

EDIT: I've got an order in for the 46135 even though I can't find any info on these things. Found a few results for 40135, but I figured I'd take a gamble on the more unknown thing and report back here.

Here's what I ordered;

https://www.aliexpress.us/item/32568...Cquery_from%3A