Yet another battery.

JJH said:

Like a couple of previous posters I’m not a fan of battery tenders. Never used one. Never replaced a battery on any of the modern bikes I’ve had since 2000. JJH

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Regardless of the battery maintainer. The bike ran perfectly 5 weeks ago on an all day ride. Is it normal for a battery to completely discharge on bike? With ignition off what kind of leakage would be expected. I have no sat nav or any other equipment fitted.

Or is 5 weeks unused normal to have to recharge?

Danny88 said:

Regardless of the battery maintainer. The bike ran perfectly 5 weeks ago on an all day ride. Is it normal for a battery to completely discharge on bike? With ignition off what kind of leakage would be expected. I have no sat nav or any other equipment fitted.

Or is 5 weeks unused normal to have to recharge?

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Over the winter I put mine on charge for 24 hours, if bike has not been ridden for a month, using Optimate 4 and directly connected to the battery, I do not use that weird canbus plug, otherwise no charger needed when bike is ridden, however my bike is a GS LC

JJH said:

Do you use any kind of charger when not riding? JJH

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Yes I’ve always used an optimiser or similar. First battery lasted circa 3 years (decent enough life), second was an Odyssey which after about 3 months generated a fault which put the bike into some sort of emergency mode of operation, 3rd was a motobatt which wrapped its hand in a week before its warranty expired. Now on a BMW (extortionate price) battery. Watch this space!!

I think the longest I’ve left my bike is 3 weeks without use. I have an alarm. Bike is kept in a block built garage. I cannot see why 5 weeks would be a problem for a healthy battery. The only comparable example I have is my lawnmower which lies idle from now till March. I will give it 24 hours on a ordinary 12 volt charger around Christmas. The last one lasted 13 years. Now I like to make the comparison of a 1200cc twin cylinder high compression bike engine and a 4 cylinder fairly high performance car. Very few car engines have a compression ratio as high as the bmw engine. When you press the button/turn the key by far the greatest resistance the battery and starter motor has to overcome is pushing that piston up or along that bore against the compression. On a 4 cylinder car engine you still only have 1 cylinder on the compression stroke. Also you usually have a much bigger battery. That is why I liken starting a bmw is like starting a 2.4 liter car but you also have a higher compression ratio to contend with. The battery must be in tip top condition. JJH

DaddyPaddy said:

Yes I’ve always used an optimiser or similar. First battery lasted circa 3 years (decent enough life), second was an Odyssey which after about 3 months generated a fault which put the bike into some sort of emergency mode of operation, 3rd was a motobatt which wrapped its hand in a week before its warranty expired. Now on a BMW (extortionate price) battery. Watch this space!!

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The R1150 does not fully charge an AGM battery. I’ve had an ‘01 and an ‘04 and in each cash I modded the vreg to boost the alternator to charge at a higher (correct) voltage. I also use a charger designed for AGM. When I realized the AGM batteries needed a higher charging voltage, I reconditioned both PC680s by discharging them to 10 volts and then fully recharging them, 5 times.

The battery on the ‘04 is now 7 years old and good as new and the battery on the ‘01 is at least 6 years old and in great shape. Both hold a full charge.