I keep a voltage meter programmed for 6s voltage and a low voltage alarm together to alarm when one P group goes below some threshold or the entire packs voltage gets too low to let me know it’s time to unplug… they usually alarm at the exact same time. It gets balance charged via charge only BMS.
6S power tool packs are great with their little built in BMSs, they automatically cut off when empty.
6S batteries --> boost converter --> watt meter works great. Boost converter limits the amp draw (mines set to 4A). Hills and acceleration don’t make a difference on amp draw with this setup, constant amp draw, remains stable regardless of load. I just notice 4A worth less voltage sag on my saggy 25rs
Thanks so much for explaining the entire project. You are very patient with me. I get it now. I thought Bacon was building a custom 6s3p while attempting to burn his place down. So I was like why not a 10s2p without all the toys?..
I love this boost converter. If you take it on a board, be sure to pot the components with some e6000 or silicone or something to help resist vibrations. I did this, but missed a single mosfet, and when it failed a few months in it was that mosfet that I didn’t glob e6000 around.
I don’t know exactly, it’s clear, goopy, dries into a slightly flexible putty, and it’s sold in fabric stores and Walmart but the name is from something about being able to withstand 6000 volts of electricity or something, I guess it was originally designed for electronics?
I may be wrong, but in my search for neutral cure silicone locally, e6000 came up a lot on the Google…
And I may have misused the term potting but a quick Google said potting was for helping electronics withstand vibration so it seems like the right word to use in this case.
And you have never heard of e6000 for real?
I’ve never used it as conformal coating. It’s way too globby and thick, I wouldn’t use it for conformal coating.
Be careful with that converter, if it doesn’t have a fan to cool the heat sink it will over heat at higher than 4A. I burnt my hands on it last time lol. After adding a fan I can push 8a with a holdable heat sink
Did a first charge with my portable charger, battery 10s2p samsung 22p with bms, 15A 900w voltage boost module, watt meter on boosted side, tiny charge bms and cell checker.
I set the unloaded voltage to 50.4, when I started charging the charger was giving out 1A then adjusted it to 3.5A output. the charging slowed down and finished at 49.8v 4.15v/cell not sure why? checked later with my Icharger and the cells where balanced within 10mv.
Everything stayed very cool during charging.
Just read all this, great idea, went to my box of bits and pulled out this boost converter I had used in the past as an led driver, looks like I’ll be making a portable charger as well😊
Sometimes it will stop a little early if the current drops below about 60mA. You can just set it a little bit above your actual pack full charge voltage to get the last little bit of charge. Eg. I set my 12s to 50.5 and it usually charges to 50.3
Loop key to power up and a separate key to connect the charge port. It mounts straight onto my charge port and charges my 12s4p at 4 amps. It adds a little over half of my standard range so a nice little boost.
I checked out this thread a while ago and also wanted to go down the charging route at first. However, after thinking about it, and taking into account that charging batteries while they’re warm isn’t ideal, I decided to try a different way.
I’m currently working on finishing up the build and taking some pictures, but basically I’ve added a port to my board which connects to the output of my antispark switch. When I want to use the external pack, I turn the antispark off, cutting flow from the main pack, and I plug in the external pack which then connects directly to my vescs. This allows me to use each pack independently and prevent unnecessary wear on the cells, or any energy loss due to the use of a converter. Current limitation is the 30A continues rating of the port I’m using. Haven’t had time to extensively stress test it yet, but it seems it can handle regular cruising totally fine. I’d use this dual pack setup for long trips regardless with the intent of distance rather than crazy shredding. Even then, the external pack can be used for distance, and I can switch to the onboard pack when I want to dial up the amps.
