Stromer ST2 Battery Upgrade (814WHr -> 983 WHr) Possible?

Rick Huizinga

Active Member
With the latest firmware in a 2015 ST2, is it possible to swap out a 814WHr battery for the higher capacity 983 WHr battery?
 

Geoph

New Member
I'm rebuilding my first 814 watt hour pack as of today. I have un-packed all the cells and have the caddy ready for the new ones on the way. (Samsung OEM) I have searched long and abroad for images of the actual ST2 pack removed from the casing, but had to revert to taking apart my own ro reveal the actual assembly. Once I am successful on a rebuild and testing on my own ST2 battery, I will help with those wondering how to re-power their own Stromer batteries. I am an ST 2 owner since 2015 and will be testing the rebuilt pack extensively in my own ST 2 here in Seattle Washington. Questions welcome.
 

Robie

Active Member
Looking forward to your results. I am sure your aware of Grin Technology.com if you need help in Vancouver.
 

JayVee

Well-Known Member
Not to be put into all hands. But providing you have some expertise with batteries, it should be possible. A 1010Wh refurb has been available in Switzerland from a 3rd party for quite some time.
 

iulianc

New Member
Hey @Geoph fellow Seattle guy here, waiting for my ST2 to arrive, bought it used off eBay. Can you share how the battery rebuilt worked? I am pretty handy, curious about the level of difficulty. Thanks
 

Chuck E. Cheese

Active Member
I'm rebuilding my first 814 watt hour pack as of today. I have un-packed all the cells and have the caddy ready for the new ones on the way. (Samsung OEM) I have searched long and abroad for images of the actual ST2 pack removed from the casing, but had to revert to taking apart my own ro reveal the actual assembly. Once I am successful on a rebuild and testing on my own ST2 battery, I will help with those wondering how to re-power their own Stromer batteries. I am an ST 2 owner since 2015 and will be testing the rebuilt pack extensively in my own ST 2 here in Seattle Washington. Questions welcome.
I bought a "not working or for parts" 814 Wh gold battery on eBay a few months ago for $150. I planned to have a friend who is in graduate school (and has access to the University's battery lab and spot-welder) rebuild it. When it arrived I found that it actually worked just fine. It has 75-80% the capacity of the original one I got with my ST2. At some point I will want to have it rebuilt, and my friend will be leaving his university post in December. I would love to hear how your rebuild goes. Please take lots of photos and chart your progress. Thanks in advance!
 

Geoph

New Member
Chuck... My rebuilt pack is done and working. I went through some pains to spot weld the cells. My welder overheated and provided less than satisfactory connections. I had to revert to solder and copper to salvage the pack. I have plenty of pictures of the re-pack and cell structure if you like. Cheers, Geoff.
 

Chuck E. Cheese

Active Member
Chuck... My rebuilt pack is done and working. I went through some pains to spot weld the cells. My welder overheated and provided less than satisfactory connections. I had to revert to solder and copper to salvage the pack. I have plenty of pictures of the re-pack and cell structure if you like. Cheers, Geoff.
Thanks for the update. I'd love to see some pics. Is solder sufficient for this kind of build? I though a weld was necessary to create a solid connection unable to be broken by heat or vibration and to minimize resistance.. I don't know how hot the individual cells get under heavy current draw, but on rough surface those cells are getting jostled around pretty good. was it easy to remove the old cells from the pack and insert the new ones? It seems like a pretty tight fit. Nice job. Hope it serves you well!
 

Charles Peck

New Member
I am very curious if those photos of the gold colored stromer battery rebuild are still available.

I will be needing to deal with my 2015 st2 battery some time coming up I am sure.
 

Charles Peck

New Member
Not to be put into all hands. But providing you have some expertise with batteries, it should be possible. A 1010Wh refurb has been available in Switzerland from a 3rd party for quite some time.
Would you be kind enough to provide some method of getting in touch with this 3rd party refurbishing or upgrading stromer st2 batteries to 1010 watt units kind sir?
 

Ravi Kempaiah

Well-Known Member