Backup Battery Power for a MotorBike

[kospap]

Hi all!

this question is about the needs of a friend of mine...

He has a year old bike (a BMW 600GS with the Rotax engine) and he is concerned with electrical power dependability....He uses his bike mainly for short excursions in our mountain, taking dirt roads that are most time passenger car capable too...

As I said he is scared of the battery failing (getting low) and having an immobilized bike... So he is searching for alternate ways to start the bike.

What I have said to him is that this is not a big concern..he sould be scared of total battery failure instead (broken elements connection).

So the best option – I feel – is a second battery carried in the luggage cases...
I forgot to tell that he already has a Genuine BMW Battery Charger/Analyzer (and an expensive one too)....So he can charge any stand alone battery too...

So what is left is to find a way to put the backup battery in....

1. the bike has an 12V outlet and I have seen car emergency chargers that use this, but can it handle the startup current? I know for a fact that the car circuit is spec’ed up to 10A, but something tells me that this is too low for startup.

2. Install both batteries and use a special switch...have seen them on jeeps and excursion vehicles. But this is difficult, expensive AND definitely violates the BMW policy and guarantee.

3. Learn to change the battery himself...the bike manual already furnishes instruction for it so this might save his guarantee too...

Then another issue arises...What battery?

Would he served by a SLA battery or he has to resort to a regular bike battery?

And at what Ah rating? He gave me the impression that the original batt is rather big for a motorbike, and will not fit in the cases....A smaller one means a lower rating and will that be enough for several tried at startup?

There must be experts here since we are an active lot, so what are your suggestions....

Also what other bike-related emergency items are usefull? I can cover him very well on personal kits but none on bike related...

thanks all, kostas

 

[kwild]

Re: Backup Battery Power for a MotorBike

If the bike does not have a kick start(buddy has a bmw but I dont remember) then he should be able to hold the clutch in, bike in second or maybe even third gear, start pushing it, jump on and pop the clutch. A hill works even better. Make sure the key and kill switch is on lol. Even on a newer bike with electronics this should still work. Old school stuff.

 

[Tough Guy]

Re: Backup Battery Power for a MotorBike

Tell him to sell that piece a junk and buy a dependable motorcycle.

 

[Switchblade]

Re: Backup Battery Power for a MotorBike

He should be able to mount a second battery under the rear fender(ala Buell Blast style) or down low by the swing arm. ANother place is across the frame in the front down in front of the engine. The new gel batteries are good for stuff like this. SImply put a race type switch on the circuits, wire in each batter so they can be switched OFF or ON. Then all he has to do is remember to change the switches when the one battery is charged to insure the second battery gets an equal charge. It's really a simple matter of mounting, wiring, and rolling on.

 

[Lindy]

Re: Backup Battery Power for a MotorBike

I put a quarter of a million miles total on two BMWs, one an R80 and the other a K75. Never had a battery failure. Tell your friend to find something else to worry about.

As someone else mentioned, though, they can be push-started. Starter or solenoid failure is more likely than battery failure, if you just keep water in the battery, and a spare battery won't help with those.

 

[The_Punisher]

Re: Backup Battery Power for a MotorBike

Just do good battery maintence, clean, dielectric grease, etc. Bike would push start with gravity, neutral get rolling (less resistance than in gear with clutch), once rolling along, pull clutch and pop into 2nd gear, release clutch all with ingition on!

 

[The Mechanic]

Re: Backup Battery Power for a MotorBike

park it on a hill. 2nd or 3rd gear start

 

[kospap]

Re: Backup Battery Power for a MotorBike

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: The Mechanic</div><div class="ubbcode-body">park it on a hill. 2nd or 3rd gear start </div></div>

wrll I know that trick from my old car (circa 1975!)
but with so many electronics I do not think it is wise...(like in cars)

He may have a good reason to worry..the next model out (a higher capacity GS with the boxer engine) was recalled fue to precisely repeated batt failures...(somehow they screwed up using chinese batts in the German masterpiece bike)
AND my latest experience with car batts is with a batt that got unsusable due to broken connection between two of the inner elements.
The shop we called hinded at this from moment one.

so I do have my worries too...

Switchblades solution is viable and reasonable and even a basic bike maintainer can do this, but as i said there may be warranty issues...

so for the time being I think a second batt unistalled is not a bad idea...so if so at what Ah?