Submitted 1 month ago by sobchak@programming.dev to askelectronics@discuss.tchncs.de
I’m wondering how practical it would be to drill and tap terminals to add posts to batteries like this: batteryhookup.com/…/2x-sunwoda-lf314-314ah-lfp-pr…
The description says that you can only drill 5mm at most. Anybody do something like this before? I do have a shitty Harbor Freight drill press and couple hand tap wrenches.
It can be done, but I would suggest doing it outside to be safe. Set the depth stop on your drill press so you can’t go too deep.
You will need a normal tap to get started and a bottoming tap to finish threading the hole all the way to the bottom. 5mm is not a lot of thread to work with in soft aluminum. Those terminals are intended to have bus bars laser welded to them.
5mm is tiny
I’d sooner invest in the spot welding tools.
NaibofTabr@infosec.pub 1 month ago
You can get handheld spot welders intended specifically for battery terminals for US$30-50. Spot welding is a lot less likely to damage the cell or risk puncturing it. Here’s an example:
ebay.us/m/adsJwa
sobchak@programming.dev 1 month ago
I don’t think those would work for these large batteries. I have one that I use for small cells though (i.e. 18650/21700).
NaibofTabr@infosec.pub 1 month ago
OK, I’m no expert but it says this at the end of that product listing:
Are you saying they need a heavier gauge bus bar for the current, something too thick for a small spot welder? Would you MIG/TIG weld a battery contact?