Bmw r1200gs battery??

[Dodgy69]

On Sunday the might GS stopped. Dash went wierd, speedo stopped working. Pulled into lay-by and tried to re start but no. Mate got his trailer.

Rung around, googled and there is some scary potential like alternator being engine out job etc. I tested battery on optimate 4 and says OK, but ???

Think I'll try a new battery and take from there. Any recommendations, book just says says agm 12v 12ah.

If charging system knackered it's a 2k job.

[KungFooBob]

I've just replaced my battery.

The one I bought from Tayna wasn't the correct one, it was maybe an inch short. Still works fine, just wedged a bit of foam the under it.
The one I bought was...

PTZ14S Powerline Motorcycle Battery 12V

It was £32 delivered.

[Rockburner]

On Sunday the might GS stopped. Dash went wierd, speedo stopped working. Pulled into lay-by and tried to re start but no. Mate got his trailer.

Rung around, googled and there is some scary potential like alternator being engine out job etc. I tested battery on optimate 4 and says OK, but ???

Think I'll try a new battery and take from there. Any recommendations, book just says says agm 12v 12ah.

If charging system knackered it's a 2k job.

I don't know a huge amount about the 1200 series. Could be a duff wire in a loom? Have you checked out the bmw specific forums? There's generally a lot of knowledge there that you wouldn't necessarily pick up from googling.

[Dodgy69]

Just spoke to tech at work, he reckons it sound's more like a bad earth. Wouldn't start with jump leads. Dash doesn't work and headlight sometimes stays on when ignition off. My optimate 4 says battery good.

[Taipan]

Stick a jump lead on the negative terminal to a good earth point on the frame. That'll tell you if its an earth issue.

[Dodgy69]

Good earth points seem hard to find on first glance. Will give another go.

[Skub]

I'd try a new battery first before worrying about anything else. In my (limited) experience with boxer twins,they like a battery to be tip top condition and they used to be quite sore on batteries.

[mboy]

Don’t scrimp on batteries on big twins… need a lot of cold cranking amps to get them going! And a cheap battery will always be the first point of failure…

Genuine Yuasa and nothing less IMO… Think it’s a YTZ14S in that bike but double check first, I might be wrong…

[Dodgy69]

Update...battery is knackered 7.6 v. Put jump leads from car and now reads 13.8v. Dash all normal. Push starter and click coming from starter relay, no power to starter motor. Thinking is, relay is knackered aswel. Tomorrow gonna bridge black and red at relay, bypass relay switch and see if starter motor turns engine and fires up.

[KungFooBob]

Sometimes, just jumping it doesn't work if the battery is fubar. You need to give it a minute or two connected before trying and make sure the car is running!

[MrLongbeard]

Update...battery is knackered 7.6 v. Put jump leads from car and now reads 13.8v. Dash all normal. Push starter and click coming from starter relay, no power to starter motor. Thinking is, relay is knackered aswel. Tomorrow gonna bridge black and red at relay, bypass relay switch and see if starter motor turns engine and fires up.

Chuck a battery at it, this is my Striple hooked up to a running car, you can hear it running in the background and see the voltage as measured at the bike battery, won't even try and kick the starter motor in, 1 new battery later, job jobbed.

[Yorick]

Sometimes, just jumping it doesn't work if the battery is fubar. You need to give it a minute or two connected before trying and make sure the car is running!

No. No. No. Never with car engine running. Can blow the electrics on the bike.

[KungFooBob]

Sometimes, just jumping it doesn't work if the battery is fubar. You need to give it a minute or two connected before trying and make sure the car is running!

No. No. No. Never with car engine running. Can blow the electrics on the bike.

Why?

Maybe if your car alternator is over charging and your bike has no fuses.

[Yorick]

Sometimes, just jumping it doesn't work if the battery is fubar. You need to give it a minute or two connected before trying and make sure the car is running!

No. No. No. Never with car engine running. Can blow the electrics on the bike.

Why?

Maybe if your car alternator is over charging and your bike has no fuses.

Dunno. But seen it mentioned a million times before. I just assumed it was dangerous.

[Count Steer]

Sometimes, just jumping it doesn't work if the battery is fubar. You need to give it a minute or two connected before trying and make sure the car is running!

No. No. No. Never with car engine running. Can blow the electrics on the bike.

Why?

Maybe if your car alternator is over charging and your bike has no fuses.

Everything I've seen about using jump leads car to car says with engine running. Can't see why a bike should be different.

As mentioned above I reckon the battery is kaput.

[Dodgy69]

Same output so see no problem. Should know more tomorrow.

[Taipan]

I'm with Yorick here, never jump a bike from a running vehicle. A spike can kill your ecu.

[mboy]

Same output so see no problem. Should know more tomorrow.

Voltage...? Yes...

Current... Noooooooooo!

As others have already said... Should never jump start a bike off a running car battery or anything else with a much larger potential current spike. On your BMW GS the CANBUS system would probably save the ECU and just trip out, but you might not be so lucky. On most bikes a current spike could easily fry an ECU, or melt a regulator/rectifier or even burn a stator. Just not worth the risk IMO...

[Yorick]

I'm with Yorick here, never jump a bike from a running vehicle. A spike can kill your ecu.

Yeah. What Shandyman says

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[Count Steer]

I'm with Yorick here, never jump a bike from a running vehicle. A spike can kill your ecu.

Well, you live and learn eh?. (Not that I've ever tried to jump start a bike with a car, but have done car to car many times). Puzzled as to why a car on tick over would have an output spike and why this isn't a problem for a modern car on the receiving end too. (Our 'laptop on wheels' car instructs you to have the 'donor' car running).