medusa569 said:
one pack measured 18.17 V and the other measured 290.24 volts.
I'm assuming that "290.24" volts is a a typo, and it's supposed to say 20.24. Otherwise something is probably wrong with your voltmeter.
For series wiring that should have given me 38.41 volts but that 's not what my meter is getting. It 's reading 20.62.... I don't get it. The connections look right so have I missed something?
Unless my eyes are just getting lost following the curlicues of the wires, I'm seeing the same thing.
both negatives (black wires) are tied together at the batteries.
the positive of the lower righthand pack is at the red anderson via the fuse, and the positive of the upper lefthand pack is at the black anderson.
Wired like that, measuring across the andersons you should get only about 2v, the difference between 20 and 18. If you're reading anything else, then either something is wrong with your meter or your connections/wires.
To get them in series for a 10s battery, you have to wire the positive of one pack to the negative of the other. Then the negative of the first pack becomes the main negative, and the positive of the second pack becomes the main positive.
Once that's done, you also have to charge up each cell individually so they're all the same, before you bulk charge the pack, or some will end up undercharged and some overcharged. If you are going to put a BMS on there to do teh balancing and prevent that issue, it'll still make it easier on teh BMS if you do this.
If you want them in parallel, for a 5s battery, then you'd wire both negatives together as you have, and then both positives together. Then run your red anderson via the fuse to the postives, and the black to the negatives.
BUT: before you connect them in parallel, you should charge each pack to the same voltage so you don't get currents flowing from one to the ohter, which might exceed the charging current limits for the cells (especially if they're old). Best to charge each cell to the same voltage, but at least each pack.