Hot swappable battery packs

My goal is to design a cheap and easily replaceable battery solution. I created a bracket that accepts a GreenWorks 40V 6Ah battery. So far it works pretty well. This 10S2P battery pack is $43 on eBay. I would love to hear other’s thoughts and share my files if anyone wants them to duplicate or improve them. I think it would be cool to have a backpack full of extra batteries and see how far I can go.


Firstly, have to say, love this you’ve done really nice with this.

Secondly, does it work, and how well?

Do you have a maximum current rating of this battery pack? Is it fused or protected in any way internally?

We tend to use only high-discharge cells for esk8 batteries, unless you have enough in parallel to share the load then you can get away with lower current models.

I cannot find anything on what current this is rated to, If these were 10Amp cells, then you have 10Amp (400W) per wheel you can discharge safely.

Before you go an buy a whole collection of these, probably best to check they aren’t really crappy cells in there. Or at least investigate the limit so you can set your VESC accordingly

It does work, but I’ve only ridden it once for about 20 minutes. It can go faster than I’m willing to ride. I cut one of my two packs open but did not recognize the cells. I added a 7A fuse while building it and swapped it out for a 30A fuse for my first test ride. The 30A fuse popped when I was testing out the acceleration uphill. I almost fell off, so I replaced the fuse with a direct connection. I rather fry my battery than fall off my board. I rode it for 20 minutes without the fuse in a hilly neighborhood, and the pack didn’t get hot. The pack is wired 10 series 2 parallel. I’ll open the pack up tonight and post some pictures. If I can get away with only running one pack, that would be great. Eventually, I would like to create two more battery pack bays for an extended range. Three packs will give me 12Ah and around a 15-20 mile range. Even if the cells are crappy, it will be 6x the amperage of a cell.

Would be good to know what cells are in it. Also if it is wired through a BMS/cut-off or if those terminals are direct from the cells.

Yeah more in parallel will spread the load better. The more current you pull from the batteries the less capacity they give you, so it’ll go further if you have them all connected rather than swap out one at a time.

Also, you can limit the VESC to maximum battery current for motoring & regen, that’ll be better than having a fuse blow on you, and keep you from skating into meltdown.

I went for a 5mile ride and tested the battery along the way. The total trip lasted 24minutes. I started with 40.8v. 1.3miles 38.1v 2.1miles 35.6v 4.2miles 34.5v 4.8miles 30.0v After I past 4 mile mark I could tell it was slowing down. It started to get hot and once I hit 4.8 miles the battery went into an over temp mode and started flashing. So, it seems this battery is only good for about 4 miles. I opened the battery and didn’t recognize the cells. I did a continuity test on both positive and negative clip with the cells and it seems like there’s a direct connection that shorts the BMS.