Bob Boro Posted October 11, 2017 Share Posted October 11, 2017 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
PAS Posted October 11, 2017 Share Posted October 11, 2017 I would fully charge the battery before having it load tested. 13.6v seems low for 3000 rpms. Sounds like a dead cell to me. Others will advise! Link to comment
Mike Sawatske Posted October 11, 2017 Share Posted October 11, 2017 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
Tri750 Posted October 11, 2017 Share Posted October 11, 2017 It's 4yr old. Please just replace the battery with a quality unit and use an automatic, maintenance type charger regularly. Link to comment
roger 04 rt Posted October 11, 2017 Share Posted October 11, 2017 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
roger 04 rt Posted October 11, 2017 Share Posted October 11, 2017 (edited) 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 October 11, 2017 by roger 04 rt Link to comment
dirtrider Posted October 11, 2017 Share Posted October 11, 2017 (edited) 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 October 11, 2017 by dirtrider Link to comment
Bob Boro Posted October 11, 2017 Author Share Posted October 11, 2017 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
dirtrider Posted October 11, 2017 Share Posted October 11, 2017 (edited) 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 October 11, 2017 by dirtrider Link to comment
Bob Boro Posted October 11, 2017 Author Share Posted October 11, 2017 Again, thanks so much! Link to comment
Redman Posted October 16, 2017 Share Posted October 16, 2017 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
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