Battery Life - How long does yours last?

[lank45]

How long does the battery last on your F800GS? Mines only lasting about 2weeks, it currently has a tracker on and I'm worried that this is the cause of the issue. As new batteries are an arm and a leg (and another arm!) I'd like to not have to fork out for another.

Is flattening the battery then charging it up bad for the battery?

 

[AberdeenAngus]

Is flattening the battery then charging it up bad for the battery?

Depends on how flat and for how long.
If you manage to get it down below 9-10volts and keep it there for a while, its fooked.

If it's just too flat to start the bike but you still get a flicker on the dash lights then should be no probs - just get it on charge sharpish.

Two weeks is very short. I suspect you might be right about the tracker.
If you can, why not put it on trickle when not using it?

 

[Dean]

have you tried Opti,

Mate

mines half full all the time with two green lights to boot

 

[bobbsy]

Well, I have had mine about 6 months now, and has sat for about 1 month without starting when all the snow was around...battery has never gone flat and starts first time.

 

[StumpyFingers]

I do not have power to my garage so I use a solarizer, it uses daylight to top up the battery.

 

[lank45]

It's in the shed, so no direct power supply but one could be fudged together. What's the best charger which will connect directly into the BMW aux socket?

 

[illumeo]

i think you need a can-bus one (bmw), unless you have a direct connection to the battery

 

[Greggers]

Mine's been ok for over 2 months before now... (but in my defence I'd been rather ill!)

but last week I (like a tw@t) left my little GPS switched on and it had sucked enough out of the battery in two days to just get the dreaded click click clickety click ....

Do you have an alarm fitted?

G

 

[Greg Masters]

Every second that your battery is less than 100% charged, its life is being shortened. The deeper the discharge, the quicker the battery's demise is.

As you have a tracker on your bike that's constantly draining some juice, your battery life is going to be quite short unless you also hook the bike up to an intelligent charger. An Optimate connected directly to the battery would be ideal.

Personally, I wouldn't bother with either a tracker or an alarm. There's plenty of threads on here with problems caused by alarms and such. Take reasonable physical precautions and get good insurance.

Greg

 

[Dave Ett]

Batteries aren't that expensive, provided you're not trying to buy one from BMW!

 

[StumpyFingers]

The solarizer comes with the connections to connect to the battery, it has crocodile clips, an accessory plug as well. I fitted the terminals direct to the battery and just plug in the solar cell when I put the bike away.

 

[TheJoker]

If you're asking "What's the approximate lifespan of a battery" then the answer should be something like "Around 4 years depending on use".

However, if you're asking "How long does your bike keep charge if left unused" then the answer should be something like "Almost forever". Unless the power is disappearing somehwere. A tracker for example. You could quite easily figure out how long the batter should last. The battery is classified by capacity "Ah", "Ampere hours", your tracker should have a sticker on it explaining how many Ah it draws. To simplify, if the battery is 11Ah, and your tracker would draw a hefty 1Ah, then it'd last approx 11h before it would be drained. If your tracker doesn't have this sticker, you can measure it with a multimeter.

BUT!
CrazyCaz's F800GS kept losing charge, but mine was fine. So I started investigating. It turns out that her bike shows 0.3V at the accessory socket when the power is turned off, whilst my bike shows a flat 0V. It's going into the garage for an investigation on Wednesday.

Might be worth a check!

PS, I don't use my car regularly so I bought a cheap solar panel to keep it topped up, but it turns out that the solar panel charge confuses the hell out of the electronics of the car resulting in a myriad of error codes.