Building a custom Lithium pack for a 2018 E4. David Bissen and I sold dozens of Samsung lithium packs for Gems. Great batteries. Dave went out and imported pallets of Samsung 94ah cells, same as in the packs. This gives everyone the ability to build a custom pack for their application. The Samsung packs didn’t fit in the pre 2005 Gem’s. Now you can build the same power pack but configure it to the shape that will fit. So I bought 15 of them for a custom 2018 pack. 14 would be equivalent to stock voltage but I’m raising the voltage over stock. So building a 15s, 60v pack. This is 15 cells and a BMS being fit into a waterproof case. Hope to have it installed tomorrow to start testing.
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Nicely done Michael…
How are you securing the cells in the box? as shown the first six cells (depending on your view) will surely shift during driving?
I can’t tell what the separate material is, looks like foam?
it is a plastic kind of foam( I think closed cell). Thin pieces between each cell. thicker stuff where possible. Rows are pretty tight. But once finished will put in more foam to hold BMS and rest of cells.
I guess depending on how you run your bus bars you can hold the primary pack in place as one unit and that would keep it from shifting.
Looks great!! What kind of box is that?
Finished. Everything pretty tight. Got case on Amazon Monoprice pure outdoor $89.
They are soo tight I couldn’t move them. They sit on foam that compresses around the bottoms and the lid also has the egg crate foam in it, which forms around the top of each cell and bms. They are not going anywhere.
First test, put new battery pack on the floor of the Gem. Kept the lead batteries hooked up(fully charged) and did a 0-26mph test. 10.5 seconds. So this is the base. Time to install new battery and continue testing.
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Nice build, these cells are solid!!
Im finishing the big brother for a 2022 gem
Same cells you’re using, same voltage but double the capacity 14s 2p. (28cells total)
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that thing is a monster!
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installed lithium pack, set voltage to same as fully charged lead. left lead in the Gem to keep weight the same. Only a 1/2 second increase. Removed lead batteries, 320 lb reduction and ran it again. Time dropped to 7.9 seconds, diffidently quicker. Plugged in charger, charged to 56v and shut off. Watched it on the bms and it went from full output to shutoff, no tapering. This makes me believe the BMC is controlling charging and shutting off charger. Need to find a way to bypass it or increase it’s voltage output. Want to get this pack to 60v.
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Charger is controlled by the BMC, and also the SOC in the dashboard.
I think you’ll need to reprogram the Charger to get it to 60v
The BMC can be reprogrammed with Digital wrench for Long distance batteries but it won’t change the voltage.
Do you have a schematic wiring diagram for newer Gems?
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Yes, I have a book. Some people have it in pdf
LG the schematic wiring diagram is at the end of the service manual I just sent you. I prefer the PDF style manual over hard copy manuals since you can Zoom in. Zoom feature is almost required for schematics.
Got it John, thank you. Found what I was looking for. Hope this works.
How much would one of those set ups cost and what else would need to be changed in my cart. 2006 e-4
Thanks for sharing all of this by the way !
Inwo sales the cells for $100 ea with hardware. For a 2006 you would need 20-24 cells depending on what speed and range you want. BMS is 250
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2006 charger may not be programmable. Using 20 or 21 cells will charge ok with original lead profiles.
I have cells snd kits in Fl., or I can Fedex a drop in 20s Samsung battery that is ready to go now.
$2500.
I also have a Goliath battery that is over double capacity and less than twice the cost.
@LithiumGods may have smaller less costly batteries in Fl. Very soon.
And @djgabriel2004 is working on a Tesla powered version of Goliath.
The Samsung module is the most tested and simplest to date for 2005 to 2015 Gems.
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