Decided to document my conversion in the hopes it will help someone in the future.
I have a 72 volt 2002 Ford Think that I’m installing three 16s Chevy Spark batteries into. Chevy Volt batteries are similar. Gem’s are also very similar to the Ford Think except for battery placement.
First I decided to remove the cooling system elbow, hoses and brackets to trim down the size. I removed the four nuts and four long bolts and took the brackets and hoses off.
I had to stand the packs on end and stand on them with one foot while reinstalling the bolts. The pack separates a little when the bolts are removed.
Now the packs were trimmed down enough where I would have plenty of room to make them fit into the battery tray. Picture showing one pack done and one not yet.
Because the packs are 16s each I needed to convert them to 8s each so when I hook them all up in series I would have a 24s pack. My goal is to have 96 volts max when the batteries are charged to 4 volts per cell.
I first drilled out the bms rivet that goes to the cell I was separating. Make sure to drill deep enough or the cells will not be separated.
Next take an ohm meter and make sure you have an open circuit between the two cells you just separated. If you do not you must drill or cut some more until you have an open circuit.
Then holes must be drill into the two tabs so jumper cables can be installed.
Always take a volt meter and check for voltage between terminals you intend to connect. You should have NO voltage.
Test fit the batteries in the battery tray. I have a two inch gap on one side that I will have to figure out how to fill to keep the batteries secure… Other than that they fit perfectly. Thinking I will add a strap or two when I’m done just to make sure they don’t go anywhere.
Next I started the bms wiring. I decided I will mount the bms on top of the passenger battery. Because I split the battery packs I have duplicate cells so I have to run a jumper wire between each cell.
You can test bms and communicate with it by connecting B- and 1 jst pin to B+.
If anyone wishes to duplicate this Spark conversion, there is a low cost spark battery listed in Ca. right now. 2015. Not 100% sure about 2015 specs, but it’s less than 1/2 what I pay for 2016 + 2017.
Also a cheap 2016 in Ca., but they won’t ship it.
One Spark will do two 110ah Gem conversions. 6 16s modules as shown.
2015 and newer. 2014 uses different chemistry. However there are some 2014 28s 90v modules listed on ebay.
Grant tested a lot of batteries. The spark is his fav.
Well now Bolt, but can’t find another.
Fuse is shown to feed bms and lcd.
I would like to get you everything you might need so I don’t nickel and dime you.
Say $40 + $10 shipping.
I’ll accept an offer if that’s too much. Mostly for my time. I pulled it all out of my junk box.
So if you want extra parts let me know. I’ll add an extra short bar to be safe.
I’m working on getting another Spark pack. (that I don’t need)
It will do two high mileage conversions.
Same price.
$450 x 3 (1/2 full Spark pack)
88v 120ah
