[derf]

So my battery is dead, very dead. I left the key on for 3 weeks plus super cold and my trickle charger wasnt connected. Totally my fault. The bat is showing 2.5 v, so I'm sure I need a new one.

So I jump the bike today, runs fine and rides fine, but every once in a while the gauges flip out on me . The temp gauge jumps from 170 something to 288 and blinks, high beam indicator blinks and fizzles, and the speedo and tach jump around all over the place.

Just checking the gauges aren't a symptom of any other problem is it?

BTW, the bike is a 99 cbr900

 

[Busted9R]

sounds like the power is surging like the neg. is not grounding out. or positive touching frame?

i dont see why it would just start doin that,

try riding it all day then leave it on the trickle till it comes back up and holds

 

[RICK-ITFC]

If your ridding with you lights on and breaking a lot, on low revs, then they will muck about. You would be better of leaving bike on trickle charge over night.If you do i recon it will be fine on next ride.:thumb:

 

[Reaper1999]

What did you jump it off of, not a car right?

 

[Busted9R]

What did you jump it off of, not a car right?

if so not while the car is running

 

[derf]

Yeh I hooked it up to my car, car was off.

And I had it on the trickle charger since saturday. Was gonna go for a ride hen, but I found the battery was dead

 

[Reaper1999]

Cause jumping from a car can destroy the alternator and Regulator/Rectifier

 

[denzee]

Cause jumping from a car can destroy the alternator and Regulator/Rectifier

Both are 12V systems so it's ok to boost if done correctly.

Your battery may have froze and broke plates inside. Does your battery charger indicate good? Test battery voltage after charging and it should be above 12.5V.

With a bad battery, many strange things can happen when running engine.

 

[derf]

Cause jumping from a car can destroy the alternator and Regulator/Rectifier

Not worried about it, jumped plenty of bikes from non running cars before. As long as the car isn't running the battery itself won't spike like an altenator can.

 

[Jason-K]

That has to be the biggest myth around....There is absolutely NO difference jumping a car with another car, to jumping a bike with a car.

The same risks apply to both situations. Just beware of transient voltage spikes that could damage sensitive electronic components, like ECM.
Try and use jump leads with inductive surge protector integrated and you will be fine.

When testing the battery, you should leave it for 20 minutes or so after removing from the charger to test voltage. After charging, there can be an artificially high surface charge that you are measuring, that dissipates after about 20 minutes.

 

[denzee]

When testing the battery, you should leave it for 20 minutes or so after removing from the charger to test voltage. After charging, there can be an artificially high surface charge that you are measuring, that dissipates after about 20 minutes.

Very true or put on your headlight for a minute or so.