Is it really the battery?

[leinsterrugby]

I know GS's have a rep for been fitted with a crap stock battery and granted they are.

BUT and here is my question - is it really the battery that is the problem or is it actuall the alternator?

The battery starts the bike and powers the eletrics while the engine is off, but while the engine is running the alternator should develop a constant voltage powering the engine and all eletrics and charging the battery.

SO is it really the battery that's sh*t or is it the alternator that's just not up to the job?

Maybe it is just that the draw can be so heavy on the alternator that the stock cranking battery justed get a chance to properly charge if the bike is only used for short rides...

Just a question....

 

[Trevor Phillips]

Got it.
High compression twin needs a lot of cranking. Takes about 10 miles running to replace charge lost starting each time. If you flit between friends/acquatainces/mistresses a couple of miles apart it will soon run down. Proper lights & GPS don't help either.
Take it for a good long run or get an Optimate - or both.
I'm still on original battery after nearly 4 years, despite having found all this out the hard way.
S**t. Is it that late?

 

[EggChaser]

Hasn't the '08 GS got the same alternator as the GSA - where the pre '08 GS models had a less powerful version

 

[cookie]

the battery is very small. when new it has the power to start your bike, but the safety margin is rather small, and it doesn't take much a of a drop in it's ability to hold a charge to make starting difficult.

the alternator has plenty of output for any normal use, including accessories. if you get a flat battery it is caused by one of three things:

1. failed charging system. rare, never heard of it on a 1200. usually a snapped alternator belt on 11s.

2. drain on the battery when parked. more likely. early bmw ecu software, aftermarket alarms, and garmin zumos amongst causes implicated.

3. battery's ability to hold a charge falling below required level. by far the most common problem.
symptoms will be masked by continuous use of optimate etc. so bike will start fine at home, but might leave you stranded after overnighting further away than the lead can reach.

 

[BeemerBaz]

I know GS's have a rep for been fitted with a crap stock battery and granted they are.

If I had my way I would be on my 3rd or 4th BMW Battery in 6mths. The first time it failed me was the morning after a 400 mile ride. I dare not leave it for more than 3 or 4 days without putting it on charge to garauntee it starting when I need it.

When in scotland a couple of weeks ago when tempretures dropped to freezing overnight it was touch and go when that button was pressed, it was quite a slow whirrrrrrrrr.

I am guessing its a particular batch that are crap.

Pidcocks stated that they ran tests etc during last service and said it was performing as it should !!

The last time I cleaned it is when I returned from Scotland and had to give the neg terminal nut a slight tweak (1/8th of a turn) as it had worked lose, doubt that was fully to blame tho.

 

[Pukmeister]

When I suffered from FPC failure, I was amazed how quickly my Hawker Odyssey battery became drained through trying to crank over that big thumping lump of an engine. I had little option but to pray for a start as I was just behind the back of beyond here in Australia at the time. Luckily it can take a full charge/discharge cycle or two.

The stock battery would stand no chance, delivering that many amps that quickly would probably fry the plates.

IMHO on the standard 1200 models both the standard Yuasa lead-acid battery and the alternator are too small for the bike.

 

[Chris Terry]

My 05GS maintains the battery above 12volts with every thing on including grips servos & GPS at tick over.

 

[Thunder]

Hasn't the '08 GS got the same alternator as the GSA - where the pre '08 GS models had a less powerful version

Yes on the 2008 version the alternator was upgraded and is now the same as the GSA.

As far as it goes I don't believe there is an issue with the alternator but would agree with Cookies thoughts on the subject.

Big believer in the benefits of Odessey batteries with big twins, one of the first additions I made to the 1150 GSA

 

[Engineer]

My 05 1200 has done 34,500 miles in 3.5 years - never had a problem with the battery. From this simple evidence I conclude that the standard battery is NOT crap.

All you need to do is ride the bike and everything will be fine.

 

[davedyer]

Also pull in the clutch when starting. Esp when cold - the gearbox oil will pull on the starter.

 

[neilhayes@hotmail.co.uk]

battery

had my bike 3 weeks, done 400 miles, rode home monday morn, went to go out to day and flat battery, no extras added, not good me thinks,didnt think I need to trickle charge it 3 weeks after picking it up from a dealer

 

[cookie]

didnt think I need to trickle charge it 3 weeks after picking it up from a dealer

you don't, there's a fault somewhere. you need to get the dealer to sort it.

 

[Pukmeister]

My 05 1200 has done 34,500 miles in 3.5 years - never had a problem with the battery. From this simple evidence I conclude that the standard battery is NOT crap.

All you need to do is ride the bike and everything will be fine.

Crap is not the word I would use, the charging circuit is 'adequate for purpose' with regular use. Having watched my headlamp dim considerably with servos applied and having a fully charged Odyssey fitted, I'd say a few more watts of output from the standard 2004 models alternator is definitely desirable.

The stock battery's reputation for failure on early models tempted me to fit the Odyssey in the interest of cold weather dependability, a move I don't regret even living in the warmer climate now. The standard battery which I retainined (now a spare) still needs a top up charge from the optimate every three months.

 

[Deleted account 211025001]

I think the standard alternator is fine - I remember doing the maths when I first bought the bike and it's more than up to running my fogs, rider and pillion heated grips, GPS and heated jacket plus all the stuff it's 'supposed' to do.

Andres

 

[Brian ROSEN]

Forthe record

I note that from 2004 until this year the alternator was 600W. On the 2008 model it is 720W. I have to say that I never had any problem on my 2004 model in 4 years - but it was used daily.

 

[Engineer]

Crap is not the word I would use, the charging circuit is 'adequate for purpose' with regular use. Having watched my headlamp dim considerably with servos applied and having a fully charged Odyssey fitted, I'd say a few more watts of output from the standard 2004 models alternator is definitely desirable.

The stock battery's reputation for failure on early models tempted me to fit the Odyssey in the interest of cold weather dependability, a move I don't regret even living in the warmer climate now. The standard battery which I retainined (now a spare) still needs a top up charge from the optimate every three months.

Just a thought - my bike does not have those horrible servo brakes - so perhaps that is why the battery has never let me down.

 

[Pukmeister]

That's quite likely the case. The servos are very power-hungry especially the front brake assistance. Coupled with the engine at idle hence low alternator output, it's no surprise that the battery voltage takes a hit. Despite being rated at 600 watts output, I doubt your alternator is making 600 watts at 12 volts @ 1000 engine RPM.

I noticed that when stopped with front brakes applied my servos run continuously, whereas with the rear brake only applied, they build pressure, cut out, and then pulse every few mins to restore braking force. It feels odd like a small rear end shunt as the servos pulse, but it saves battery drain when at the traffic lights etc.

My advice (based on 4yrs ownership) for R1200GS 'servo' bike owners: If you are stopped at junctions etc, hold the bike on the rear brake only and not the front.

 

[MattW]

There's a pretty much inviolable fact with lead acid batteries (whatever their type - gell / AGM / wet cell etc, etc) - once you've flattened a LA battery to below ~ 50% of it's capacity, you've started to knacker it. By knacker, I mean you've significantly reduced it's capacity. Once you've flattened it completely, the uncomfortable truth is that you will soon have a new battery in your future.

Any amount of tricky chargers / desulphators etc will not restore this capacity - it's gone. They can give the illusion of having fixed things by maintaining the battery at its maximum (reduced) capacity, which might appear to fix things as long as you aren't using too many accessories / lights, but as soon as things get cold and dark, it's toast.

The trouble is that there isn't the space on a bike to fit a really appropriate battery so you're stuck with one on a knife edge of having adequate capacity to handle lots of starting / high running loads. Throw cold weather into the mix (cold temps significantly reduce capacity) and it gets even worse. The best / only solution is to try and maintain your battery at it's maximum rated capacity by using a trickle charger and if you're doing lots of short runs, reduce the number of peripheral loads (extra lights / heated grips etc).

Or you could put a truck battery in yer top box.....

Matt

 

[Brian ROSEN]

Just a thought - my bike does not have those horrible servo brakes - so perhaps that is why the battery has never let me down.

Well my previous GS did have the servo brakes and I have to say tha I was very impressed with them....and in four years I had no battery problems at all.
I must add that the (servoless) brakes on my 2008 model also feel very light and responsive so I think that other improvements (to pads/discs/system?) have ruled the servo unnecessary.

 

[Budweiser]

I was told that you should'nt use an Optimate on a GSA, only BMW's own make