BMW R1200RT/R1250RT Forum

Hey guys,


Recently inherited a 2013 R1200RT from my dad.  It had sat for a while and the battery wouldn't take a charge or start the engine.  Got a replacement battery from the local autozone.  I assumed (first mistake) the positive and negative terminals would be on the same sides as the old battery, and didn't double check.  Positive went on first just fine, but got quite a few sparks trying to attach the negative cable.  I'm not a stranger to auto maintenance and wouldn't be concerned over a tiny spark attaching the negative lead, but this was not tiny.  I didn't try to force it and immediately stopped and disconnected everything.  Upon inspection, the new battery despite looking the same, had the positive/negative terminals on opposite sides as the old battery.  I felt stupid to put i mildly...


So my question for all you guys, what damage could this have caused?  It was connected for less than a second, but being computer controlled damage could happen that fast.  Would this have blown my ECU or other components?


All comments, advice and shame for my mistake are welcome!


Thanks!

You won't be able to assess for damage until the battery is connected, albeit back to front.
Only then will you be able to see what's working and diagnose what isn't.  Nothing wrong with having a diagnostic done, hopefully all will be well.

Connect it correctly and turn the key.  If you damaged anything it can't make it worse. If you haven't everything will work.

tintiviv wrote:Got a replacement battery from the local autozone. I assumed the positive and negative terminals would be on the same sides as the old battery.
Upon inspection, the new battery despite looking the same, had the positive/negative terminals on opposite sides as the old battery.

As the new battery terminals are on opposite sides, I'd be surprised if the original battery leads will reach the correct terminals.
Could you use some jump leads or extend the leads on the bike to test if it will work.
Looking at this photo, you might get away with just extending the -ve lead.

Thanks for the replies!


I used some jumpers and connected the battery with correct polarity this morning, and turned the key.  Computer seemed to boot up just fine, and I heard the little hiss of the fuel pump priming, just like how I remember it doing when I had it running before the winter.  No new warning lights or anything strange.  Tried to start it, but I just got the clicks I normally do when the battery didn't have a good charge.  Hooked it up to a battery tender and it only read about 10 volts, so I'll let it sit for a while and try again later.


I don't think I'll try to extend and cross the leads.  The new battery I got was a cheaper one, just to get the bike up and running around town while I looked around for a better, more permanent replacement.  I don't plan on riding much in the winter, so the bike will be sitting for a couple months at least.  I would like to get a battery more suited for that and better prepare for wintering the bike.  I've seen options for lithium and gel batteries (exide actual gel ones), that are lighter and hold a charge better over time, compared to the standard lead-acid.  I don't mind spending extra money to get something that will work right.


Whats your favorite battery?

To be honest, there's nothing wrong with lead acid batteries or gel, yes new technology is here, but at a premium cost. In relation to weight saving personally I don't believe that you will notice the difference, for example set off on a Sunday morning ride out, stop off at Ponderosa or some cafe, English breakfast, several cups of cha and Bob's your uncle, whatever you saved in weight is gone. Tried and trusted is best policy

tintiviv wrote:I would like to get a battery more suited for that and better prepare for wintering the bike.
Whats your favorite battery?

This thread on Replacement Batteries might be of interest, https://1200rt.com/index.php?topic=1165.0

My 2012 RT has the Exide GEL Battery fitted, the bike has been laid up for 5/6 months, will be hitting the starter button soon.

The RT has only ever been fitted with a heavy gel battery since 2015 I think they have been used on all variations  since the 1100 in 1996 They kill off cheap ones very quickly.. 

Looks like in 1996, the R1100RT used a "Flooded Serviceable" Battery,
http://www.realoem.com/bmw/enUS/showpar ... Id=61_0262
now ended.

You will note from the Real OEM list even though they show the battery its not listed.  The main dealer EPC shows a gel battery.  Think a few early ones might have had a lead acid in them but they haven't bothered to update Real OEM as it never seems to show alternative parts for superseded items. Go to a 2000 1150 and its showing gel.

tintiviv wrote: ...Hooked it up to a battery tender and it only read about 10 volts, so I'll let it sit for a while and try again later....Whats your favorite battery?...

A battery measuring 10V is dead. Fully charged it should show at least 12.6V. This all refers to a battery that has been standing for 12 hours without charge and without connection to the bike. For yours if you wish to test it, charge it up unconnected, assuming it takes the charge at all, then when fully charged disconnect the charger and let the battery stand for 12-24 hours. If after that time it measures at least 12.6V whilst continuing unconnected it should be ok. If it doesn't, it's scrap.

If you need a new one, then why not get the correct one for your bike as suggested by others in this thread, not just any old battery. That way it will fit in the space provided and the terminals will be in the correct location. Lead acid is fine they don't present any starting problems and will last for years if cared for. Gel and AGM are both based on lead acid technology. AGM is newer but I don't think it makes a lot of difference in practice.

If you don't use the bike too frequently then I'd advise you keep it on the smart charger (battery tender) but no need to disconnect the battery. Then you don't have to worry about a flat battery when you wish to ride.

I think there may be a misunderstanding as gel batteries are lead acid as are AGM, the main difference being the construction of the plates in AGM and the medium the acid is kept in with gel.
It is also worth noting for people who leave their batteries uncharged for over a month or longer, particularly when still connected to the bike that although the bike may start fine damage may have occurred internally to the plates that is irreversible! Which is the reason battery tenders are recommended for long term storage if the battery is not going to be charged for more than a month or so.