Jump to content
IGNORED

Discharged battery


Bob Boro

Recommended Posts

Hello All! If my 2003 R1150RT sits for a week or 2, the battery gets discharged. I charge the battery (BMW Gel, 4 yrs old) and it starts and runs fine. Once charged, the battery reads 12.5 v. At 3000 rpm, it reads 13.6v so it looks like the alternator is working. The charging warning light does not light. I've never gotten stranded, only it won't start if it sits for more than a week. Either the battery does not hold charge or there might be a slow battery drain somewhere. I am going to remove the battery and have it load tested. If it tests ok, then maybe I have a short somewhere that slowly drains the battery.

 

Am I on the right diagnostic track here? Something else to consider?

 

Thanks!

 

Bob

Link to comment
Mike Sawatske

Bob,

I had a similar problem, although I had left mine for a lot longer between uses. There is a drain continually on the battery even with ignition off, should be 2mA maximum or 0.002A on a digital meter.

At first my fancy floating charger wouldn't get anywhere with the battery, however, after a stint on an old time battery charger where there is very little control of charging current the battery responded to charging with the floating type modern charger.

That happened about 6 months ago and the battery is now going well. I am riding the bike a little more as well but I still use the floating charger when it is sitting in the garage to combat the constant drain supplying the Motronic unit. I had concluded originally that my battery was history - a nice surprise.

 

Helped a mate recently track down a reason for a new battery not holding charge for more than a day in a R1100RT. Turned out a simple one - his radio was constantly turned on!

 

Mike

 

Link to comment
Hello All! If my 2003 R1150RT sits for a week or 2, the battery gets discharged. I charge the battery (BMW Gel, 4 yrs old) and it starts and runs fine. Once charged, the battery reads 12.5 v. At 3000 rpm, it reads 13.6v so it looks like the alternator is working. The charging warning light does not light. I've never gotten stranded, only it won't start if it sits for more than a week. Either the battery does not hold charge or there might be a slow battery drain somewhere. I am going to remove the battery and have it load tested. If it tests ok, then maybe I have a short somewhere that slowly drains the battery.

 

Am I on the right diagnostic track here? Something else to consider?

 

Thanks!

 

Bob

 

Bob,

You're on the right track. Your alternator sounds fine. The battery may be bad but it sounds to me like a key-off drain.

 

Please tell us what you have connected to the battery other than stock equipment. Also, do you have a Kisan signal-minder?

Link to comment
Bob,

I had a similar problem, although I had left mine for a lot longer between uses. There is a drain continually on the battery even with ignition off, should be 2mA maximum or 0.002A on a digital meter.

At first my fancy floating charger wouldn't get anywhere with the battery, however, after a stint on an old time battery charger where there is very little control of charging current the battery responded to charging with the floating type modern charger.

That happened about 6 months ago and the battery is now going well. I am riding the bike a little more as well but I still use the floating charger when it is sitting in the garage to combat the constant drain supplying the Motronic unit. I had concluded originally that my battery was history - a nice surprise.

 

Helped a mate recently track down a reason for a new battery not holding charge for more than a day in a R1100RT. Turned out a simple one - his radio was constantly turned on!

 

Mike

 

Good advice. Just as a reference, my ‘01 GS draws 2.5 mA and my ‘04RT draws about the same. On a 16 amp-hour battery, up to 4 weeks will discharge the battery about 17% which should still allow you to start the bike.

 

One last thought, on a stock bike with no add ons, if you pull fuses 3 & 5, your drain drops to 0.5 mA. You can store for 6 months without a charger and have only discharged about 15% if you have an AGM battery.

 

Edited by roger 04 rt
Link to comment
Hello All! If my 2003 R1150RT sits for a week or 2, the battery gets discharged. I charge the battery (BMW Gel, 4 yrs old) and it starts and runs fine. Once charged, the battery reads 12.5 v. At 3000 rpm, it reads 13.6v so it looks like the alternator is working. The charging warning light does not light. I've never gotten stranded, only it won't start if it sits for more than a week. Either the battery does not hold charge or there might be a slow battery drain somewhere. I am going to remove the battery and have it load tested. If it tests ok, then maybe I have a short somewhere that slowly drains the battery.

 

Am I on the right diagnostic track here? Something else to consider?

 

 

Morning Bob

 

Does your bike have a kisan signalminder or ( sm-5)? --Those are noted for a pretty hefty parasitic drain on the battery (even with key-off).-- (I believe that Roger has modified this kisan to have a lower key-off patristic draw.

 

Otherwise you definitely need to have a battery load test done & also measure the bike's electrical system key-off patristic drain.

 

OR, do a home test by just disconnecting one of the battery cables & allowing the motorcycle to sit for the same time that it now takes for the battery to go dead. If the battery STILL goes dead even when disconnected then you either have a bad battery or the battery top is so covered with acid that the battery top is an electrical conductor.

 

If you measure the bike's electrical draw & find it excessive then look for an accessory not shutting down or look for signs of greenish oxidation in one of the accessory outlets (I have seen quite an electrical parasitic drain from power outlets with green oxidation in them, especially if damp or after washing the motorcycle).

 

Per BMW service bullitin-- On the 1150RT the parasitic drain with key-off should be at or under 2.6 mA & parasitic drain with key in ® position should be at or under 3.1 mA.

 

Are you turning the key to completely off & not to (P) parking or ® radio?

 

Added: I see you have a BMW Gel battery?- if you feel like digging then get the battery's manufacturing code off that battery & call your BMW dealer as BMW had a series of defective Gel batteries a few years back. ( Per BMW-- Locate the battery's manufacturing code. Batteries that have a code greater than 252 03 53 are not affected)

 

 

 

 

 

 

 

Edited by dirtrider
Link to comment

Thanks DR! I do not have a Kisan but I do have a few questions:

 

1) How do I measure parasitic drain? This would be handy for me to know.

 

2) Is 13.6 v adequate charging output?

 

Thanks so much for your help!!

Link to comment

Afternoon Bob

 

1) How do I measure parasitic drain? This would be handy for me to know.-- Just remove one of the battery cables from it's battery post, then put your multi-meter on the 10 amp scale (first), then place one multi-meter lead on the battery post & the other on the removed cable end (make darn sure your ign key is not on or you could blow the meter's internal fuse) . This will give you a rough idea. If the amperage shown is below 1 amp then reset your voltmeter to the mA scale & see what mA number shows. (this is your patristic draw)

 

Added: if you have more than one wire or cable attached to the battery post include all of them when testing between battery post & cable/wires (this gives you total patristic draw). If draw is high you can then test one at a time to isolate a specific circuit for high draw.

 

2) Is 13.6 v adequate charging output?-- Yes, well sort of, 12.6v is on the low side but is about all some 1100/1150 alternators are set at. That should keep a Gel battery up just fine for normal riding.

 

 

 

Edited by dirtrider
Link to comment

On my 1150RT, when it was new to me, and an old battery, I found that what I thought was OFF on the ignition switch was not entirely OFF and the radio was still powered. You might want to look into that.

 

.

Link to comment

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...