Guru
Joined: 13/10/2014
Location: AustraliaPosts: 2193
| Posted: 09:01am 18 Dec 2023 |
Hi Klaus, they looked even worse when I first extracted the cells from of the case. I will be making my own to replace all of these. The two Links I made and tested the other day work beautifully.
All four batteries were assembled the same, it looks like a supply shortage for that batch of batteries back then.
The other sets were bought about 2 months later and use the same thick high current solid links, but correctly sized. I think the hump in the links are also there for the expected dimensional changes in the Prismatic cell Posts and case swelling, more or less over their life time, I think most of the initial swelling happens at the factory from the initial charge discharge cycles for grading etc, if not abused they appear to have little change after that.
I guess it also depend on the quality of the cells and other environmental / load / charge conditions.
None of these cells were clamped and I'm not doing that now in light of the way I use them, I leave about 4mm space between all cells when I assemble the cells into the desired configuration.
I also have a 48V 16 cell EVE bank which uses the copper links you describe, these are two layer links with some flex, very nice units and the cells have solid meaty quality terminals.
EDIT: Also looking at the picture notice the mismatch of washers and spring washers, along with only partial contact with the full cell terminal surface due to the hacking of the links.
.
Edited 2023-12-18 19:04 by KeepIS