batHot and power loss. Options?

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12lee
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batHot and power loss. Options?

Hi All

For the past week my 2007/2008 Vectrix VX-1 has been giving the battery warning light, then the battery temp light and batHot message about 5 miles into a 10 mile ride. Today it lost power. I managed to nurse the machine to its destination. I have some questions...

1. What's the likely cause? Bad temp sensor? Bad battery (individual)? Bad batteries (collectively) :S
2. How to best diagnose?
3. What are my options for fixing? I'm mindful of the cost of a new battery pack vs the value of the machine :(

Thx

Lee.

ofx210p
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Re: batHot and power loss. Options?

How many Kms do you have on it. What is your normal range for discharge. How long ago did you ride it regularly ? (or do you ride it regularly?)

Sorry for all the questions but i am sure they are pertinant.

12lee
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Last seen: 12 years 1 week ago
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Re: batHot and power loss. Options?

10,000 Kms
Ridden virtually every weekday on a 40km round trip. Regen is used during the trip and average speed is around 50kph.
It gets recharged (fully) daily.
The normal indicated range is around 60km and it's generally charged up from showing 2-5 bars capacity until a full charge.

Symptoms started to show after 3-4 days of not having been used. Prior to that period of non-use it had never shown bathot.

Rgds

Lee.

marylandbob
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Re: batHot and power loss. Options?

What VOLTAGE does your battery charge up to? (Is it at least 142 volts?)

Robert M. Curry

12lee
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Last seen: 12 years 1 week ago
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Re: batHot and power loss. Options?

Given that the bike is now showing 0 range and no battery bars, I'm nervous to plug it in to charge.

I am certain that over the past week I have been seeing around 152cp while charging. Does this sound plausible?

L.

antiscab
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Last seen: 10 months 1 day ago
Joined: Saturday, July 7, 2007 - 23:55
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Re: batHot and power loss. Options?

Hi Lee,

For the past week my 2007/2008 Vectrix VX-1 has been giving the battery warning light, then the battery temp light and batHot message about 5 miles into a 10 mile ride. Today it lost power. I managed to nurse the machine to its destination. I have some questions...

1. What's the likely cause? Bad temp sensor? Bad battery (individual)? Bad batteries (collectively) :S
2. How to best diagnose?
3. What are my options for fixing? I'm mindful of the cost of a new battery pack vs the value of the machine :(

You almost certainly have a bad cell.
At present its lost most of its capacity
Its probably also directly under a temp sensor (which is why you are getting a battery temp error message)

A bad temp sensor will just cause the error, but doesn't affect the way the bike rides at all

If you keep riding it as is, the cell will go short circuit, and the bike will actually be rideable again
The cell will still get hot though

keep going long enough and it will send smoke signals
8 or 9 cell blocks with a dead cell don't cost much to replace

I can sell and ship one over for 150E (shipping is the killer for me, I'm fairly far away from most people)
The guy from Italy who has been doing conversions has lots of nimh batteries

easiest way to check for bad cells is to ride until your bike stops (or sends smoke signals)
if the temp warning comes on, you should probably stop for a bit
if you don't the cell will eventually vent and get a bit smokey (I was in a hurry and didn't stop)

then pull the battery apart
replace all 8 or 9 cells blocks with a bulged cell
replace any where a cell falls to ~0V or reverses while the 8 or 9 cell block is supplying more than 1A of load (car headlights make good loads)

make sure all cells are near the same state of charge (1 Ohm across each cell for 30 hours will do that easily)

Given that the bike is now showing 0 range and no battery bars, I'm nervous to plug it in to charge.

I am certain that over the past week I have been seeing around 152cp while charging. Does this sound plausible?

the 152CP where your odo normally is is just the target voltage

The actual voltage is displayed in the left display, where the est range value normally is

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km

12lee
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Last seen: 12 years 1 week ago
Joined: Wednesday, February 17, 2010 - 02:22
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Re: batHot and power loss. Options?

Thanks Matt. Sounds like I have nothing to lose by:

1. taking a look at the battery to see if anything's obviously dead
2. charging the bike and using it
3. being prepared for some tinkering/battery replacement

Was trying to avoid getting too hands on with this thing :(

12lee
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Last seen: 12 years 1 week ago
Joined: Wednesday, February 17, 2010 - 02:22
Points: 20
Re: batHot and power loss. Options?

I can now report that the bike charges to around 146V. At that point it shows bathot with the temperature and battery tell tails illuminated. Is 'use it until the bad cell shorts out' the way to go?

antiscab
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Last seen: 10 months 1 day ago
Joined: Saturday, July 7, 2007 - 23:55
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Re: batHot and power loss. Options?

I can now report that the bike charges to around 146V. At that point it shows bathot with the temperature and battery tell tails illuminated. Is 'use it until the bad cell shorts out' the way to go?

not if it can be avoided - every time the fuel gauge gets reset because one cell is empty, the rest of the cells get overcharged.

Riding it until the bike stops just means the bad cells are easier to identify

BTW - if you only have one or two bad cells, you don't have to replace them, you can get away with just shunting them out. Use at least 25mm2 cable to do it, or equivalent. (5 x 6mm2 with soldered on yellow crimp eye terminals will work)

Matt

Daily Ride:
2007 Vectrix, modified with 42 x Thundersky 60Ah in July 2010. Done 194'000km

R
R's picture
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Re: batHot and power loss. Options?

you can get away with just shunting them out.

Certainly, the cheapest way is to shunt the death cell. Remember there's 102 cells in 3 layers.
12lee
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Last seen: 12 years 1 week ago
Joined: Wednesday, February 17, 2010 - 02:22
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Re: batHot and power loss. Options?

Thanks both. Is there documentation anywhere on how to shunt out the dead cell? I have a degree of mechanical and electrical competence but I'd prefer to follow some instructions! Thanks, Lee.

Cor
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Joined: Sunday, February 12, 2012 - 22:18
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Re: batHot and power loss. Options?

Thanks both. Is there documentation anywhere on how to shunt out the dead cell? I have a degree of mechanical and electrical competence but I'd prefer to follow some instructions! Thanks, Lee.

Bolt a strip of copper from one terminal to the other of the same battery, after you measure that this is the cell with no voltage or too high drop.

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