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203K views 437 replies 177 participants last post by  pettefar 
#1 ·
I tried charging my R9T battery using a cheap battery tender with a adaptor plug into the aux socket, it wouldn't work, I tried turn on the ignition and off, it worked for 5 min then off, then I found this charger on the website TecMate OptiMate 4 Dual Program Battery Charger for BMW CANbus - RevZilla.
It seems that the charger must be compatible with the can bus system, is this the right charger? Do I have to buy one from the dealer? Any one has a good suggestion, thanks
 
#2 ·
Many people, including myself, avoid this issue and purchase the relatively inexpensive Deltran Battery Tender charger. Deltran includes the necessary direct to battery 'pigtail' to plug in the charger with the standard SAE plug.

And, while the BMW manual states disconnecting the battery terminals, that is pure phooey as I, among others, of course have used these chargers on all BMW's with no concern for many years, and more likely the prohibition based upon the notion that there are some pretty 'dirty' chargers out there.

I currently have three Deltran Batter Tender chargers, charging three BMW cycles with CAN-bus technology with these chargers. I hedge my bets a bit by putting them on an inexpensive light timer so that they charge for only one hour per day.

Good luck!
 
#97 ·
Many people, including myself, avoid this issue and purchase the relatively inexpensive Deltran Battery Tender charger. Deltran includes the necessary direct to battery 'pigtail' to plug in the charger with the standard SAE plug.


I have a four bank Deltran charger; two dedicated to Harleys, one dedicated to the 9T and one spare. Connected the positive lead to the positive battery connection under the 9T seat and the negative lead under that bar that the OEM battery terminals are connected to. The Deltran will not work if the positive and negative leads are connected directly to the to battery posts under the seat. The negative lead needs to be connected to ground.
 
#5 ·
I happened to ask my BMW dealer about battery chargers today and he wanted to sell me the Optimate 4 with CANbus over the BMW charger.
 
#8 ·
What is it that makes a CanBus charger special? Limitation of current? Special Voltage?

I could see how a high amperage charger would be really tough on some wires and circuits if they were not heavy enough and that seems to be a problem because you can't have more than a 5 amp draw on the accessory plug.
 
#13 ·
I've got a CTEK MXS4CA charger and was told by my bmw dealer that it would be ok to use this hard wired to the battery and not go through the socket on the side of the bike as long as i dont turn the key on. Anyone got step by step on how to hook up a pigtail connection to these bikes. I've found the obvious red positive post under the seat but was wondering where is an easy and suitable spot for the negative if it's suppost to be hard wired onto the battery. I can't see the battery as yet and that could be another thing if someone has a method to get to it. Wasn't too keen to rip apart a new bike without knowing what i'm doing first.

Any help is good help. Thanks.
 
#14 ·
I use a CTEK 0.8, positive wired to the positive post terminal and the negative under the screw holding the piece that holds the positive terminals. (Does that even make sense to anyone other than me?). Compared resistance at that point and at the negative post on the right throttle body (jump start point) and it measured fine, It's not my preferred arrangement and I will connect directly to the battery once I figure out how to take the tank off...
 
#15 ·
Hey Jugg, you won't need a step by step as you are already half way there.
Attach your (+) to either one of the red positive posts that you have found; they are connected so doesn't matter which one.
The motor and frame are both grounded to the negative side of the battery, so any point direct to motor/frame is ok; (beware of plastic guards and spacers though).
I have my (-) under one of the screws just towards the rear of the ECU box. The lead follows the upper frame tube and it all tucks away neatly. The screws are either side about where the back of the rider's seat is.

I have the SAE connector poking out on the RHS to the side of the plastic airbox. And when I'm not using it, I tuck it into the slot down the side of the same plastic airbox; don't know why the gap is there, but is handy for this.

Hope this is all clear. ;)
 
#16 ·
Thanks for the advice guys. I hooked it up as you suggested and left the charging plug sitting behind the air box in the little gap that's there. Quite handy indeed. I've not used the charger yet but multimeter testing suggests it should be all hooked up correctly. I ended up hooking the positive to the positive jump post and the negative through the right hand bolt that holds the bracket where the 2 positive terminals are. This offered 0.00ohms resistance to the negative jump point on the engine. I'll probably hook the charger up this weekend to give it a run and fingers crossed nothing blows up...lol.
 
#200 ·
Thanks for the advice guys......I ended up hooking the positive to the positive jump post and the negative through the right hand bolt that holds the bracket where the 2 positive terminals are. This offered 0.00ohms resistance to the negative jump point on the engine.
Hi all,

Did the above with my trusty Halfords 2/4A motorcycle battery tender/charger which I used on my previous Honda Crosstourer for years. Connected the pigtail to one of the red posts under the plastic cover and the other to frame, on the RHS screw under the plastic carrier for the two Battery +ve terminals just behind the tank under the seat.

My bike is 5 days old and the battery seemed a little low on switch on at 11.9v. A few days commuting a short distance to work and it was 12.9 at rest. Plugging in the charger after coming home with heated grips on, the battery took about 20-30mins of charge then the charger went into trickle mode. On switching on after removing the charger, display shows immediate battery volts at 13.2. The reg/rec seems to provide a constant 14.4v when engine running so everything seems to be OK... ?
 
#20 ·
Here's some pretty good advice. Yuasa Batteries -

Jussi is right about the alarm, K1600 manual has something about how long you can park with an alarm. It's not very long. If your battery goes flat, you shorten its life. I'm not looking forward to replacing mine. Looks like the tank and airbox come off first.
 
#23 ·
Battery Charging 9T

The 9T can have its battery charge maintained by plugging in a charger into the on-board socket. Many chargers have this featured plug and can be used in this manner which creates quite a convenience and eliminates the need for adding wires to the batter for plugging in such a unit.alexford
 
#27 ·
Battery charge


I don't know. Rider's Manual suggests using a BMW unit. An educated guess is that any system that monitors full charge, which is known to it, will work. I already have an over-priced Porsche unit which has a motorcycle setting. It monitors the battery's output and automatically stops to keep the plates in prime condition. There are American units that do this, often sold by the various battery stores around the country. alexford
 
#59 ·
Think a LONG extension cord :) Or hold off on new carbon, and get a plug run in there. Tried to do that in my brother in law's barn which was built in 1883. Electrician wouldn't do it. Said the building was below code LOL. Bought a cheap honda generator at a flea market to power some lights when I'm working on old cars out there.
 
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