moshe_levy Posted July 5, 2006 Share Posted July 5, 2006 Hello Fellow Oilheads- Some background, as this is my first post here: This weekend, my girlfriend and I both purchased some pristine '04 Oilheads. Hers, an R1150R and mine, an R1150RT. Both are like new, and we're going to get used to them before taking them cross-country next spring. I'm attempting a crash course in Oilhead basics, and do not yet have the owner's manual and service manual in hand yet (they're coming, though!) Here's my question: On my other bikes (two airheads and a Harley Sportster) I have a standard fused connector that runs from the battery directly out - from there, I can connect to the usual Deltran type "battery tender" trickle charger. I have two accessory outlets on the RT - if I can get the Deltran to BMW type connector, can I plug the battery tender right into those sockets to charge, or do I need to hook a pigtail up right to the battery like all the other bikes? I ask, because I saw that some sell a BMW to BMW connector where you plug into the accessory outlets to recharge a dead BMW from a live one (so to speak). Thanks in advance for all your help - I hope to learn alot here in the coming months. -MKL '04 R1150RT / '73 R75/5 / '74 R90/6 / '98 HD 1200C PS - As luck would have it, here in NJ, the government is on shutdown due to some bogus budget crisis. That means I can't register my RT, so for now I just get to stare at it in the garage! My luck..... Link to comment
Edgar Posted July 5, 2006 Share Posted July 5, 2006 Attach the BMW plug to business end of the charger, paying attention to + and -, and plug it in to the power socket of your choice. Simple as that Link to comment
RFW Posted July 5, 2006 Share Posted July 5, 2006 Why do you need to charge the battery? Unless you intend to leave the bike unused for more than a month or so, there is no point whatsoever in charging the battery. All excess charging does is increase plate erosion, and boil off water. A lead-acid battery of any type (flooded cell, AGM or gel) is perfectly "happy" to sit for a month of 6 weeks, and still start the bike just fine. Link to comment
DavidEBSmith Posted July 5, 2006 Share Posted July 5, 2006 There's some parasitic drain from the clock, and a Battery Tender-type "smart" maintenance charger won't appreciably boil off battery water. Link to comment
moshe_levy Posted July 5, 2006 Author Share Posted July 5, 2006 All- I am aware of the effects of charging and discharging batteries. I sell UPSs (Uninterruptible Power Supplies) to the defense industry for a living. I don't plan to let the bike sit for long - I was just curious if the sockets that are already on the bike could be used for the purpose of charging. -MKL Link to comment
PoPo Posted July 5, 2006 Share Posted July 5, 2006 I do just that to my '01 (S). I put a BMW socket on the end of the Battery tender and just plug it in. I have noticed no problems. To my knowlage there is no diode in that circut on any of the bikes. No reason it shouldn't work! My .02 PoPo Link to comment
RFW Posted July 5, 2006 Share Posted July 5, 2006 There's some parasitic drain from the clock, and a Battery Tender-type "smart" maintenance charger won't appreciably boil off battery water. The parasitic drain is on the order of a few milliamps only, and not enough to be significant inless the bike sits for a month of 6 weeks (a constant 10mA drain, results in only about 7mA-H of capacity loss ...less, actually, since the battery's ampere-hour rating is determined at a much higher drain. Extremely low discharge rates result in an apparent increase in the battery's A-H rating. As for a battery tender not boiling off water, it all depends on WHAT battery tender. To achieve this, the charger must float the battery at a very accurate, temperature compensated voltage, and it must be designed for the specific battery type (flooded cell, AGM or Gel). In particular, Gel cells are extremely sensitive to float voltage and overcharge. Not all float chargers or battery tended are accurate enough. Link to comment
philbytx Posted July 6, 2006 Share Posted July 6, 2006 What Edgar said As far as Battery Tender's go...I use them on 3 of my vehicles. One on the bike and 1 ea on Deb's Subie and the other on the GQ (my 95 E34 Bimmer). I keep them on BT's all the time.... I use the BMW adapter on one and I put pigtails on the auto batteries and just hook them up, takes about 30 secs. Now, I use the E34 about once or twice a week and Deb uses her Subie daily. The E34 battery is 6 years old and in great shape, my RT battery is 4 years old and in great shape. There is no issue with hooking your bikes up to a BT on a daily basis if you want to.... Link to comment
RFW Posted July 6, 2006 Share Posted July 6, 2006 There is no issue with hooking your bikes up to a BT on a daily basis if you want to.... But what on earth is the benefit? Link to comment
Hedge36 Posted July 6, 2006 Share Posted July 6, 2006 There is no issue with hooking your bikes up to a BT on a daily basis if you want to.... But what on earth is the benefit? Lack of surpising and irritating ABS failure light sequence, for one. A lot of people don't ride that often, so "tending" the battery is a good idea. Link to comment
Hedge36 Posted July 6, 2006 Share Posted July 6, 2006 Oh, and RFW: you'll know the battery has gone flat on your bike when the starter relay welds itself together. That'll happen before you notice a lack of cranking power. DAMHIK. Link to comment
RFW Posted July 7, 2006 Share Posted July 7, 2006 Oh, and RFW: you'll know the battery has gone flat on your bike when the starter relay welds itself together. That'll happen before you notice a lack of cranking power. No it won't. Contact welding (like any sort of spot welding process) requires high current to pass, for a finite time to generate enough heat. Heat can not be created instantly!. Typically it requires at least a second or two of attempting to crank with a low battery, before enough heat can be generated to cause contact welding. Long before this occurs, it will be obvious that the motor is cranking dangerously slowly, and any sensible rider will release the starter button rather than continuing, knowing damage may result. But that isn't the real point. The point is that I stated that a battery, left unattended for a month or so, STILL has not been discharged enough that it cannot easily start the bike. If only 3-4 weeks elapses between the time the bike is started, I was simply stating that there is no benefit in keeping the battery on constant charge, because it will ALREADY be in a good enough state of charge to start the bike just fine. If it isn't, then the problem is the battery is shot, and the solution is to replace the battery, not to bandage the situation by putting a defective battery on charge all the time. For longer periods of inactivity than 3-4 weeks, then I agree....put the battery on charge. Link to comment
BMT Posted July 7, 2006 Share Posted July 7, 2006 No it won't. Oh, yes it will. It's because the coil is under-excited, so the relay contacts are not fully together. The resulting arcing welds them together. It must be one of the most common 'gotchas' on a BMW. Link to comment
Hedge36 Posted July 7, 2006 Share Posted July 7, 2006 Did you skip the voltage/amperage equation in BEE? Link to comment
GordonB Posted July 8, 2006 Share Posted July 8, 2006 Best solution....Don't let the bike sit for 3-4 weeks Link to comment
BMT Posted July 8, 2006 Share Posted July 8, 2006 Did you skip the voltage/amperage equation in BEE? No, it was after that. DC circuits containing large inductive loads. Link to comment
Hedge36 Posted July 8, 2006 Share Posted July 8, 2006 Did you skip the voltage/amperage equation in BEE? No, it was after that. DC circuits containing large inductive loads. Link to comment
Recommended Posts
Archived
This topic is now archived and is closed to further replies.