Chevy Volt Battery Install -> 2000 GEM 4 seater in San Diego

Well, here goes another Chevy Volt battery install thread… Feel like we have this pretty well covered in other places but wanted to try to contribute back to the community as I go through my install.

My setup -

2000 GEM 4 seater
Ride-4-Fun Motor
New T2 Controller
NEV Disk Brakes
14" wheels

I currently have some cheapo marine Duracell batteries installed that were great for about 9 months and then I just started getting crushed by voltage sag climbing the hills in my area. My goal is really hill climbing power and the ability to maintain 35 mph on the flats so I don’t get run over by traffic. I usually don’t go more than 10 miles without putting it on charge for the night.

I did the usually rookie mistake of replacing motor and batteries before going lithium. As I’ve learned through reading the posts, you should start with Lithium and then mess with other components after. About a year ago, I picked up 4x 48V 12S Chevy Volt batteries from Ebay and a Chargery Charger and BMS from @Inwo. Chalk it up to a number of things (our youngest is just about to turn 1 so we were dealing with that) and I’m just now getting around to dropping in the batteries.

First question for the group - What should I do for a charger?

Let me explain - the original owner put in 2 3 bank 12 volt battery chargers when the on-board charger crapped out. 1 is mounted under the dash and the other under the rear seat. I was thinking about leaving 2 wet cells in the front for weight and to power the accessories - light bar, radio etc. and then put the volt batteries under the rear seat. Should I just charge with the Chargery and not have an onboard charger? Should I get a Delta-Q with the Lithium profile and can I mount that under the seat without connecting it to the Controller? Best place to source a Delta-Q? Suggestions welcome

Next up, have to drill holes at the bottom of the battery for all-thread to hold the cells together and then I’ll saws-all off the water jackets. My plan for securing the batteries to the car was going to be to use an angled metal piece to marine starboard to the frame. Open to ideas though if any one has suggestions.

This will be a somewhat slow thread… I travel a ton for work and have a 4 and 1 year old… but I’ll try to document the process as I go. Appreciate the commentary and help along the way. And thank you to everyone that’s posted about their installs… I’ve read just about every lithium thread multiple times!!!

J Just a side note: Were the Duracell batteries AGM or flooded?

Flooded - these

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Thanks. I just bought a set of ATM Duracells and I’m hoping too get a few years service out of them before I go the lithium route. Good luck with your swap

When I saw the photo of your car I recognized a few thing’s. I guess your the Guy that bought them from me, and your light bar install is how I do them. Cheers !

It’s cool to see people getting use from Ideas & projects we share. :slight_smile: did you do the floor mounted “foot stomper switch” for the Light bar on and off ?

@grantwest - yup! That’s your mat. Part of the reason I bought it was that I wanted to check out the material for potentially putting in my boat so it was dual purpose. I think it’s a great look for the GEMs and I might go with another color once I’m done with my battery install. (want to do it in the boat but have been chasing some mechanical gremlins this summer). Since you sent me the original template drawings, I was able to email plasdeck and they could make up new mats with whatever colors I want using the work you’ve already done.

Funny you mention the foot switch, took a little head scratching to figure out what that was for and I connected the dots when I was doing the light bar install… and found your other post. That was super easy too.

This forum is great and the info you guys post is invaluable. GREAT way to learn about these cars and the things you can do to them.

Be careful drilling through bottom for bolts.
I also did the volt conversion. Went to drill bottom holes and ended up smoking a cell in the pack. You won’t need to drill them. I just used stainless hose clamp kits to hold the packs together. Some others have used either metal and nylon banding. You shouldn’t have to cut all water jackets on all batteries either. Should only have to cut both on the middle ones and none or just one on outside batteries. If using up front, maybe get away with no cuts. Be sure to measure your carts dims. They can vary quite a bit I’ve found.
One more thing, my buddy cut too much off the water jackets and actually exposed some black substance. Not sure what it is, but not energized and seems to not be a problem. I wouldn’t cut that far if I did it again, only about half way through the water jacket itself.

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I’m with Hbbill. Only cut what you have too. I cut mine even with the side of the battery. It worked but got a little close and I went the metal bands way and when I tightened them up the side cracked and the packs got a little close. Just be careful and take your time.

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I took the advice of @Hbbill and @BadBrad and decided not to drill holes at the bottom. I already had stainless hose clamps at the top and used bench clamps to secure the battery to the workbench while I did the cuts. My plan is to use a second set of hose clamps at the bottom once I get a chance to run out to the marine shop (only place I’ve been able to find that has stainless hose clams that big).

Let me start with tools -

Used a Milwaukee 6" Saw-all metal blade (new), a Ryobi corded reciprocal saw, and Irwin Quick-Grip clamps.

You guys got me super nervous about cutting too close so I marked a line down the bottom of my battery as my “do not cross”. I was pleasantly surprised how easy it was to make the cuts and my saw didn’t really wander at all. Feel like I over stressed on this one! No damaged cells, nothing exploded, and I still have all my fingers.

This now messes up my plan to secure the batteries to the car. I was going to use the bottom bolts to attach to a 90 degree piece of metal and the other side to a piece of starboard in the battery tray. What have you guys done to secure the batteries in a volt install?

Also wiring - I was planning to run new 4AWG battery cable. I’ve seen folks using 1AWG and a combination all over the place. I think 4AWG is what the car came with from the factory? Is that sufficient?

Next up - remove the old batteries and marine battery chargers, figure out where/how I want to mount the shunt, and figure out securing the batteries to the car.

IMO use two hose clamps with a worm screw on each long side for more tension.

I can’t find a picture with sawed jackets. It works the same way.
Use all thread to clamp. And the bottom flange of aluminum angle to screw to frame.
Picture is a formed piece. Later I used 1" x 2" angle from frame to frame.


Good idea… I don’t know why I had in my head it had to be 1 big hose clamp vs. 2 combined. I’ll do that

Looking good. I mounted my shunt opposite the fuse on the other side. Worked out nice with the cabling.

Do not let the shunt short to ground.
Do not let bms-24t case contact metal. It is poorly isolated from internal electronics.

You can get a steel band kit that will allow you to make any size clamps you want. Much cheaper than buying individual clamps and putting them together. I’ll try to get a picture of the box. Had enough for two gem conversions.
I used most of the original battery wires with two from the volt pack. I really liked their cables and would always try to get the entire module just for those and all the stainless hardware if nothing else.
Still just using a cheap ratchet strap from harbor freight and some wood blocking to hold everything down. Seems to be working fine. Nothing is moving, But thankfully, I haven’t ever rolled my Gem! I will get something better installed eventually.
Enjoy your newfound power and post some pix.

Breeze Make-a-Clamp Kits. I think the 4000 has 8’ of strap and a couple of screws.

I’m overdue to post an update. The wife was out of town (which never happens) and I was homebound with the kiddos. Figured I’d take a couple of days off to spend in the garage and work on the GEM.

For strapping the batteries, I liked the idea of using steel straps but the kits were pretty pricy so I decided to go with poly. Got a setup off Amazon for around $180. Ended up putting 2 straps around each battery. I made them pretty snug. Not sure how tight you can go on these things and if there is a too tight? The corners seems to be bending so I figured that was good enough and didn’t want to crank anymore.

Next up was to strip the car of the stuff I didn’t need. Pulled the batteries, removed the old battery wiring, removed the 2 marine chargers, etc.

Out with the old and starting to put in the new stuff -

Connected the spoof… that was pretty straightforward when you get the wiring harness out of the controller. FYI - I’ve been following a bunch from this thread which is a very similar setup to what I have in terms of year GEM, Charger, BMS, and batteries.

Now it’s time to figure out the shunt mounting. I bought a block of UHMW Poly off ebay. Cut it down to the right size with a combination of my tablesaw and chop saw. Then it was time to put the dress press to work.

Counter sunk the bolts so the shunt bolts wouldn’t touch the frame… and the screws attaching the shunt mount won’t touch any metal. Think it came out pretty clean but I’ll let you guys be the judge.

Now it was time to dry fit the batteries and figure out which way to position them. Fit easily with the water jackets off but I’ll have to come up with some blocks to secure them and keep them from moving around. that will be one of my last steps

I’ve had a battery lug crimper hiding in my garage from boat projects a while ago, so I used that to make custom fit battery cables using marine grade 4g wire. Used red and black heat shrink to help me keep things straight when I’m hooking everything up.

Ended the day wiring up most of the batteries. Have the packs paralleled and the cables run from the controller B- to the shunt and the battery disconnect switch to the fuse.

Goal for tomorrow is to at least get a test drive in; stretch goal will be to get the delta-q mounted. I’d like to get the BMS in but let’s see how far I get. Figure I could always use the chargery charger and the BMS in the interim, Delta-Q last.

If you see I’m doing something screwy or have suggestions, I’m certainly open to them!

Will get another update out in a day or so.

I ran out of battery lugs for making cables so I figured I’d work on the install of the Delta-q. I did a mock up just holding the charger against the firewall and realized there wasn’t enough aluminum vertically to meet the top and bottom mounts. I’d have to figure out a way to extend the aluminum firewall and get the 1 inch spacing so the cooling fins weren’t hitting the components on the left and right side.

Went to the hardware store with the charger in hand and some pictures to see what I could come up with. Ended finding some square 1x1 aluminum. Figured I could cut these to length and use them as rails to mount the charger to the firewall.

I used bolts to go through the rails and into the firewall. Used self-tapping metal screws to mount the charger to the rails. As other’s before me have noted, it’s a snug fit. A little worried that heat might be an issue when charging. I’ll have to do more research on what someone (a think Dave @Inwo) suggested about putting the charger on a timer to cycle on and off.

One other thing I did and changed. One of the threads had the charger with the DC side facing down so I followed that. Then read the installation manual and it said it’s recommended to have the DC side facing up so I spun it around. Wondering if it matters or there’s a reason for going DC side down. Guess I’ll find out when I wire it up if there are issues with space.

pic of the charger flipped with the DC up

one bone head move when drilling one of the holes… let the AC side insulation rub against my drill chuck and it wore some of the insulation away. Can’t see any of the cables so hoping this is fine. Someone smarter than me let me know. Just sucks screwing up something that’s brand new!

Error code 77… that’s where I’m at right now.

Got all the batteries wired up, double checked, crossed my fingers and threw the disconnect switch. Nothing sparked or set on fire so that was good :). Dropped the parking brake and the solenoid clunked, a little accelerator and I get error 77.

Checked the voltage from the batteries and I was at 96.5. Have had the headlights on for 3-4 hours now and am reading 95.7. Still getting the error (mind you, I have an inexpensive multimeter that I got off Amazon so who knows how accurate +/- .X it is .) . Pretty sure I read that 96 was the hard limit for the T2s so I’m guessing I just have too much voltage.

Did I miss a step somewhere to get this going? Is there a controller setting I need to adjust on the T2? I have the spoof installed in Pin 1. In the meantime, figure I’ll leave the lights on until it gets down to 95.0v.

code 16 is the high voltage error code and 77 is over speed so that’s interesting you get that sitting still.
Have you tried unplugging the motor speed sensor? My T1 will still move and gives no error when I unplug the motor sensor.