New Battery Pack in My CuMoCo C124

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PJD
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Joined: Wednesday, November 22, 2006 - 05:44
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New Battery Pack in My CuMoCo C124

I just completed an installation of 24 new 60AH GBS cells in my 7 year old C124 and it is running fine. The old cells were still serviceable but power and range was suffering.

The cell replacement was bigger than the big job I thought it was going to be - between getting all the cells charged and balanced on the bench-top and shuffled onto the battery tray. Then there were the estimated 400 screw removal and replacements with those 4-screw cell terminals and BMS connections. At least GBS now uses Torx-head screws. I also rigged a much improved syatem of restraint straps for both the 12-cell rows. CuMoCo did not restrain the cells well at all against swelling and so most of the old cells were visibly bulging.

I had only one glitch - after the first ride with the new cells last week, bad weather kept it in the garage, then yesterday evening, I attempted a trip out to the pub, but the scooter would, on any amount of slope, go 2-3 meters then shut off, to be repeated when the throttle was returned to zero and twisted again. The light on the Kelly was green, so I figured that it was another case of the BCU over-reacting to a minor condition. Fortunately, I have the BCU Access software and hardware which can do an OBD-style scan, configure, or-flash the BCU**. So I was able to immediately diagnose it as a open battery pack temperature sensor circuit at the connector to the BCU - which I was able to fix.

Why John and Eric programmed all these ways to leave a rider stranded over the most trivial detected faults is something I will never figure out. Could you imagine owning a car that shuts down every time a CEL code is thrown?

And while the big front fairing piece was off the scooter, I put LED headlight lamps in it - 50% more light at 25% of the power consumption!

The only thing left is to figure something useful to do with the old cells. I'm thinking of using them to build a UPS for my house - I figure they still have enough capacity to keep the refrigerator and (now all LED) lighting going for two days, - or in winter, the gas furnace and refrigerator and lighting going for one day.

Anybody else out there with a CuMoCo scooter still running?

------------------------

**Only a few owners were able to get the BCU access and the BCU firmware before the "angel investors" of CuMoCo put a kibosh on it becasue they thought John Harding's programming, even just the compiled firmware code, was some kind of valuable intellectual property - which also went a long way to assure the failure of CuMoCO (and their investment).

LCJUTILA
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Re: New Battery Pack in My CuMoCo C124

My C-130 still works great!

LCJUTILA

PJD
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Re: New Battery Pack in My CuMoCo C124

You may be the only other owner of a CuMoCo Scooter still running!

LCJUTILA
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Last seen: 1 month 4 weeks ago
Joined: Monday, May 21, 2012 - 07:23
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Re: New Battery Pack in My CuMoCo C124

I think what saved my bike is I had an early problem with the BCU and they sent me a new one.
They blamed the problem on the 12 vdc power converter getting too hot and frying the BCU.
I switched out a bunch of incandescent lights to LED to lessen the load and keep the BCU cooler.....Seemed to solve the problem.
I also do NOT keep the battery topped up.
If I fully charge the bike, it is right before I am going to ride it.
Then, after I knock off ten miles or so of charge I leave the bike in a slight state of discharge until I am going to ride it again. Only then do I top it up, if necessary.
At one point I was riding the bike 47 miles (both ways) to work, 94 total. I'd charge it up for the ride home while working.
I like the scooter but it was rather expensive.
Best of luck with yours!

LCJUTILA

PJD
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Joined: Wednesday, November 22, 2006 - 05:44
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Re: New Battery Pack in My CuMoCo C124

Yes, the mounting of the 12V (actually 13.5V if I recall) DC-DC converter in the same box as the BCU was a design disaster and the cause of most scooters being retired. My switch to LED's (even the headlights) is why mine is still running. And yes, keeping the pack less than full is important - charging full only occasionally to balance the cells. I learned that a bit late. I even practice it on my Smart ED car.

The other items that have kept my ED running is the hardware and software to configure and re-flash the BCU. Wiring up voltage check points for each cell using the BMS wiring has been very useful. For example In the past couple months, the BMS has stopped balancing cell no. 1 but I was able to discover the problem before this cell was getting way overcharged and now I simply discharge this cell a bit (through a string of taillight bulbs) every few times that it is charged full.

I'm still hoping that there is still a cache of old C-124/C130 parts in Ann Arbor somewhere. I have been unsuccessful at contacting any former CuMoCo engineers.

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