R1200RT Battery type and charger

[SeattleVic]

I just realized that I posted this on the oilhead section, so re-posted it here:

 

So, I'm a new member, and I really did read all the other posts I could find on gel vs AGM vs lead acid, and Battery Tender Plus vs BTP Gel vs BMW Gel charger vs BMW AGM charger.

 

I feel like I've been on acid.

 

So, I called my service department, and they said the R1200RT's do NOT come with gel's. They're either sealed AGM's or lead acid.

 

Has anybody with an RT actually pulled their battery and checked? I guess I'll do so this weekend.

 

Here's how I see the equation. If this is not correct, I'd appreciate comments:

 

1. If gel, use BTP gel (021-0156) or the BMW advanced charging system (about $80). The BMW version will work with the bike thru the socket, the BTP will not, and may zap the fragile electronics.

 

2. If AGM (or lead acid) use the regular BTP or the BMW gray 6-led unit (about $120). The BMW will again work thru the socket.

 

Using the BTP should be via a pigtail to the battery (with a fuse of course). BMW recommends you disconnect the battery from the bike.

 

If you do use a BMW charger through the accessory socket, you have to turn the key on, plug in the charger and then turn the key off.

 

Why they made it this difficult is beyond me. I'm tempted to bypass the electronics and wire the accessory socket directly to the battery (and fuse), but I probably won't.

 

Does anybody actually own the pricey little gray AGM unit? Does it really work thru the accessory as advertised?

[JamesB]

I had heard that the R12RT only comes with the AGP sealed battery. Yes the grey charger works through the front accessory socket. (Currently have one.)

 

What is not clear (to me) at this moment is if it does a proper job of maintaining the battery in this mode. The directions imply that the led's cycle from red up to green (showing full charge). All BMW chargers I've had before, stop at green & maintain a charge. This one cycles back down to the primary red charge led -- which then blinks slowly (which implies it is performing an "anti-sulphate" operation -- but this doesn't actually make sense for a long time with a new battery). Have been trying to check if this is proper. No firm answer yet.

 

One thing you might consider, however, is that if you ever want to have an electric load larger than minimal amps, the stock front outlet is limited.

 

Rather than get the $120 charger consider adding a relay controlled accessory bus to the battery, a rear socket wired to the bus (which will then handle more amps) and use a cheaper (gel) charger. The net difference may not be all that great and give you greater versatility.

 

Other threads discuss this.

 

Good luck.

[ShovelStrokeEd]

Why they made it this difficult is beyond me. I'm tempted to bypass the electronics and wire the accessory socket directly to the battery (and fuse), but I probably won't.

 

Why not wire it directly, fuse protected of course, and eliminate all the hoops BMW is putting you through.

 

As to charger type vs battery type, the charging system on your motorcycle makes no distinction, why, so long as you are only doing maintenance charging, should you? I'm pretty sure the only time you would need a special charger is if you were dealing with a fully discharged battery or the initial charge on one of the battery types.

[MarshMan]

I have the grey $120 charger on my ST. It performs the same cycle as was previously mentioned. My dealer would not sell me any other charger, and I'm pretty sure the 12RT has the same setup. BTW, this setup is purely a maintenance situation. If your battery is DEAD I believe you cannot use the jack because of the CANBUS so you need to access the battery directly and I'm pretty sure the little grey charger won't do squat.

[Ken H.]

What Ed said. BMW is making it difficult, but you don't have to keep it that way. Wire a external connection (even if it's a modified accessory socket) directly from the battery and use any 'smart' "tender" type charger you have. The battery, the bike, and your pocketbook will be fine.

[SeattleVic]

What Ed said. BMW is making it difficult, but you don't have to keep it that way. Wire a external connection (even if it's a modified accessory socket) directly from the battery and use any 'smart' "tender" type charger you have. The battery, the bike, and your pocketbook will be fine.

 

I'll probably just do that, like I did on the Harley, and assume that BMW's scare tactics about disconnecting the battery first are bogus

[gjnockie]

Just thought I would chime in about what I did regarding battery charging.

 

I purchased a Black & Decker Smart Charger for $17.44 at Walmart, it works with all types of batteries, Gel, AGP, Deep Cycle, etc. It has a 5 year warranty and it has 2 power levels too. (1 to 2 amps).

 

The downside is that the pigtail that it comes with is very short so you need to make it longer. I bought some 18 guage lamp cord, soldered the wires and finished them off with shrink wrap tubing. Total cost $2.00.

 

The unit is wired directly to the battery and I used cable ties to neatly route the wire to the frame rail in front of the right bag. When not in use I simply tuck the wire up behind the fairing.

 

Bottom line the charger works great and is very cost effective!

 

2005 RT1200 RT

2005 Harley Road King Classic

[JayW]

My R1200RT came with its own charger at no extra charge - its called an alternator. I plan to run it at least monthly all year and not bother with the plug in chargers. I figure I can bundle up enough for a 20-30 minute ride even in the coldest TN months.

 

Jay

[Brimoon]

FWIW, here's the official word from the Blue & White god:

[dwayrider]

I installed a Powerlet covered socket in the fairing where the radio controls would go and wired it directly to the battery. I plug a Battery Tender directly into it. It works the way I want it to work, maintaining the battery.

 

Obviously, my solution would not work for RTs with radios.

[eddiea]

I had my dealer run an external connection directly from the battery and use my smart tender (gel type from my now gone LT)it works fine, I was told by my dealer that "I do have a gel type in my RT? I'm comfused.

[dwayrider]

You can mount Motolights on the 12RT, and someone posted photos here some months ago of PIAAs (1100x?) hung simply upside down under the front part of the rear view mirror housings.