charging problem

[754144]

The battery on my 600v transalp will not hold a charge despite being only 5 weeks old.
I try and start the bike in the morning but will not fire due to very weak spark but bike will start no problem when jumped off another battery.

Take bike for a ride to charge battery and check with voltmeter.
Charging current is 16.2 v with bike running so battry must be charging.

1 hour later and battery has drained flat again. no lighs or ignition have been left on.

Can anyone help

[alpslapper]

Have you an alarm on the bike, or anything else that might be tking a current? Duff battery?

Some other ideas here:

Battery Draining

[Orinoco]

Take bike for a ride to charge battery and check with voltmeter.
Charging current is 16.2 v with bike running so battery must be charging.

When you measure the voltage across the terminals with the engine/ignition off it should be somewhere around 12V - 13.2V. If it's less [say 10V] then it's likely that there is a dead cell in the battery. At 5 weeks old I'd take it back and get a replacement. Bikes are generally sensitive to voltage at starting, a battery with a dead cell can still start a bike if it's fully charged, but drop the level of charge and it won't.

When the engine is running the battery should be charging at a higher voltage, but 16.2V seems very high. What should happen is that as the engine revs rise the voltage should go up too, but it should stop around the 15V - 15.5V mark. The fact that the voltage is that high suggests a fault in the regulator/rectifier unit. That in turn suggests that the battery may well be damaged by the overcharging it has been getting.

[FatFergie]

That voltage does sound very high. Are the cells full or have you needed to top it up?
If they're empty or even low you'll not get a charge. You may have a faulty regulator/rectifer which has meant the higher charge rate has evaporated the water out of your battery.
Maybe?

[Lutin]

754144

In another thread, asking about battery charging on an AT, I went out and measured the voltages under various conditions - engine off, running etc. It is here -

Dead bike

What do you get on your TA?

The 16.2 Volts does seem rather excessive to me, and does suggest a regulator/rectifier fault.

[Lumiya]

From a fully functional reg/rect you should get an output of between 14.4v and 14.8v with the engine running and above about 2000rpm.

Also remember that voltage isn;t the only thing needed to charge the battery, current (amps) is also handy

Kymmy

[Lutin]

From a fully functional reg/rect you should get an output of between 14.4v and 14.8v with the engine running and above about 2000rpm.

Also remember that voltage isn;t the only thing needed to charge the battery, current (amps) is also handy

Kymmy

This is very true, but I believe that some people would find it difficult to measure the charging current. It's not difficult at all, but some folks have, how shall I put it?, an aversion to anything electrical.

[gravelrash]

hey mate i hasd exactly the same trouble mate and start your bike go for a spin and feel your battery if it feels very hot after say a 15 min journey your rectifier is shagged mate and boiling yer battery once bioled its goosed as i had 2 buy another again when i got it sorted ,and any rectifier doesnt work as on most bikes its got bto be the proper one mate i also found this out and i was over the moon once id sorted it , if the battery feels very very warm or hotish thats whats happening mate good luck mate gravel

[AlanH]

Yep. 16.2v is waaaay too high. It should max out at around 14.7 volts measured across the battery terminals at over 5000rpm. The regulator portion of your regulator/rectifier is goosed. High voltages can blow the CDI, rev counter etc as well as boiling the battery.

[754144]

funny you should ay that coz my rev counter packed up about 6 weeks ago for no apparent reason.
Are forks an easy job to change or can i expect to be reaching for my lump hammer.

thanks everyne for all the asvice