Reprogrammed my T1 controller using my Windows 8.1 laptop with a USB dongle made by Inwo

I recently resurrected my 2002 GEM car with a lithium ion pack from Hybrid Auto Center, and was looking to get rid of the jerky regenerative braking that kicks in at the speed limit. Forklift-electronics no longer makes the dongle for the T1 controller, but I found a post here where Inwo was making and selling them, so I ordered one. He shipped it right away, and my laptop with Windows 8.1 recognized it without installation of any drivers. Programming was pretty easy once I figured out that the red wire on the dongle with the pin had to be stuck into the unplugged cable in order for it to work. Once I did that, I was able to read from and write to the controller.


Thank you for the plug. I know some have reported not being able to use sentry sw with T1 controllers.
I will soon have a T1 again, so I will be able to test cables before shipping.
There is another way of connecting to the T1. It involves adding a couple pins to the 23p plug. The adapter
then stays with the car.
It makes it easier to connect computer without removing the plug each time. Also allows sentry to monitor while motoring.

I am very interested in your experience.

For one, the 23p plug does not look full populated. T3?
Theoretically the T1 dangle should not work with a T3.

What package Lithium?
Leaf cells? How Many?
Bms supplied by Hybrid?
Charger Choice? DQ Mod?

I just grabbed this pic from the internet to show connection of the red wire. It is not my controller, which is definitely a T1. The pic is accurate with regard to the population of the plug though.

I bought a 50ah 20 cell pack from Hybrid Auto Center, which uses LiTec modules. I got a BMS from Hybrid, along with a charger. The pack was $820, the BMS was $235, and the charger $225. With shipping, the whole conversion was a little over $1300. Range is a bit over 15 miles (I have 14 miles on the current charge, and its showing 30% left). Attached are some pics. Overall I’m pretty happy with the conversion. The lithium batteries drop a ton of weight, and their voltage output is pretty flat under load. A hill I used to crawl up at 5 mph I now cruise up at 20 mph. If I had to do it over, I’d go with 22 cells, assuming the controller can handle the additional voltage, just to give a bit more range.

1 Like

That’s the nicest I’ve seen.
With the bms and charger, a super deal.
How much work to connect it all?
So many are looking for this. A thread on it will get a lot of attention.
I only get a little over 12 miles on my Volt 24s pack. So I just added another in parallel this week.
I run at 100 volts. The controllers seem to take it fine. I believe they use same parts as 96v ones. You just need to spoof the controller into seeing 15v less.
I’m going to invite Rodney. His buddy is looking for drop in Lithium. This is close. He would use two packs. Is there room?

It was pretty easy to set it all up. I put the charger and battery in the same spots, and was able to utilize the existing cabling, etc. I had to run one wire from the charger to the BMS, drill a few holes, and bolt everything up. You can’t really tell from the pic, but the pack has an aluminum frame with places to put bolts. If fit the center of the battery bay perfectly, and the mount points were above aluminum plates welded to the frame. If I added two cells I don’t think it would fit in the same space, and would probably mount it in the front. The hardest part was soldering the BMS wires to the cell. My 40W soldering iron was insufficient, and I had to get a heavy duty iron to get the tabs hot enough to melt the solder.

As wired the BMS only provides balancing and overcharge protection. To add overdischarge protection I would have had to buy a contactor to disconnect the pack and wire it tot he C- lead of the BMS. I was told by Nick at Hybrid Auto that most people don’t bother with the contactor setup. He also told me that this battery could provide up to 200A for 30 sec, which would limit me to a motor with a peak draw of 14kW or 19HP. I’m currently running the stock 5hp motor and I’m fairly happy with it, so I’m not too worried about exceeding the 200A limit.

The charger does not have the NC contact for the interlock, so I initially just connected the interlock wires together and made sure to unplug the car before I drive off. I have since installed a 120vac relay with NC contact, and connected it in between the charger and power cord with a little dongle I made. When the car is plugged in, the NC contact opens, and the controller will not engage the main contactor.

As far as room for 2 packs, you could put one under the seat and one up front. I don’t think you could easily put 2 under the seat though, as it is too big for the outboard slots.

1 Like

I don’t see the 20s pack on there site. Also the 48v pack is about what you paid. Did you get special pricing?

At the bottom of this page it says “Could be made with 12-31 cells - contact us.” I contacted them, stating what I needed, and I was given a few different options for battery packs, along with quotes. This was the most economical option that fit my needs. I’m not aware of any special pricing.

I’m having good luck with 24s.
Works good with this BMS-24

That is an impressive display!