Battery / charger weirdness?

abraxas

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Hi all.

This is not really a F800GS question, but no idea where else to post.

I recently bought a new Yuasa battery for my F800GS. It is exactly the same as the old Yuasa battery it replaced. I also have one. of the CANBUS BMW chargers with 4 LEDs indicating RED for 0 amber for 1/3 and 2/3 and green for 3/3.

Genuine-BMW-Motorrad-Motorcycle-Battery-Charger-Maintainer-Conditioner.jpg


The old battery would always be on green 3/3 after being left on the charger for a while [but was 5yr old and would discharge a bit too quickly, hence the change]. Now the kicker : The brand new battery never goes past the amber 2/3 amber LED. ?! Even after days on the charger. Bike runs and starts normally, no issues. Anyone seen this? Any ideas?

Cheers.
 
Maybe the charger is duff hence your first battery being weak?
 
If you have a good quality test meter:-

State of Charge Sealed or Flooded Lead Acid battery voltage. Gel battery voltage. AGM battery voltage
100.00% 12.7 12.85 12.8
75.00% 12.4 12.65 12.6
50.00% 12.2 12.35 12.3
25.00% 12 12 12
0.00% 11.8 11.8 11.8

The charger should put out over 13 volts up to as much as 14.5 volts

Edit. Sorry the formatting didn't transfer over.
 
Thanks for the ideas guys. I do have a decent multimeter and will have a look at the voltages next. I was just puzzled how the same type battery and the same charger get different behaviour. I still have the old battery but it is a real pain in the butt to take the plastics off... The old F650GS had a "jump lead terminal" under the seat which made voltage measuring a doddle...
 


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