BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

I emailed Deltran.

There has been much debate about using the Battery Tender Plus on gel batteries, specifically on a 2004 BMW R1150R motorcycle. I have a Battery Tender Plus that I purchased in January 2001. I am hesitant to use it on the gel battery because I am not sure if it is the right one. Are there any numbers of any sort on the charger to tell me if it is capable of doing the job?



This is what I got.

We recently came out with a new charger, the Battery Tender Plus for Gel Batteries, which was specifically designed for BMW gel batteries. The unit that you have is not the recommended charger for you type of application. The part number for this unit is 021-0156. You can purchase this unit from Battery Mart, for a discounted price. You can call them toll free at 800-405-2121, or online at http://www.batterymart.com.



Amanda Hester

Customer Service

Deltran Corp.

386-736-7900

I sent Deltran an email asking about a charger for a BMW gel battery. They said the Battery Tender Plus won't work. I would have to use the charger made specifically for the BMW gel battery. This charger is sold exclusively by BMW dealers.

So they said, "Don't use the one you have, buy a new one." What did you expect?

Here's is some technical info from several older (and possibly searchable) posts here and across the BMW fora.

Battery Tender and any other trickle charger with 2 stage logic, 1.5 peak amps, and peak charge cycle voltage below 15.5 volts -- can be used with gel chemistry batteries but not the best way to do it. Very good for lead acid, acceptable for AGM. Will shorten the deep cycle and the life of gel batteries.

Battery Tender Jr. - two stage charge cycle with peak 1.3 amps and 13.85 volts peak charge cycle. Can be used but not optimum choice for gel. Excellent for both lead acid and AGM.

Battery Tender Plus - three stage cycle charger with peak 1.5 amps, 14.85 volts, and good absorption phase for AGM batteries. Better choice for gel but still not best. Will not damage battery but can shorten life by a small (< 10%) amount over several years.

Battery Tender Plus (gel) - adjusted peak voltage and adsorption cycles to approach optimum gel battery needs. Still not best for BMW gel batteries (which have a unique chemistry from other gels).

BMW Advanced Charging System for Gel Batteries. Special Deltran product for BMW gel battery chemistry pre-2005 models.

Advanced Charging System for 2005 and later, CANBUS equipped BMW battery systems. Best of the best for chrge voltage, peak amps and cycle logic for BMW and is backward compatible to AGM, BMW gel, and lead acid types.

SO if you have a Battery Tender Jr or Battery Tender Plus, you can use it on either lead-acid or BMW gel batteries. It's just not the best version to use.

The single best decision you can make with your pre-2005 BMW is to refuse to let the dealer install a BMW gel battery. Insist on a lead-acid or an aftermarket (Odyssey PC680 or Westco/Panasonic) AGM. The cost is about the same as buying a new charger.

MikeCam wrote:So they said, "Don't use the one you have, buy a new one." What did you expect?


Battery Tender Plus (gel) - adjusted peak voltage and adsorption cycles to approach optimum gel battery needs. Still not best for BMW gel batteries (which have a unique chemistry from other gels).

As indicated by your own reply, the folks at Deltran weren't interested in selling me a charger as they were in preventing me from damaging my gel battery by charging it with a Battery Tender Plus. I appreciate their advice.

There are Battery Tender Plus and then there are Battery Tender Plus. If you have the old one that was made before the gel battery comes out, then how can you expect the thing to work with your battery? The new Battery Tender Plus not only charges gel but AGM batteries as well. How do I know? I called Deltran, got their advice and bought one for my friend who has a gel battery and his wife's bike has an AGM battery. The unit also says what it's capable of charging right on the box.

FWIW, I think Deltran is a good company based on my personal experience with them. They gave me a great deal on replacing an old Battery Tender Plus that had been zapped by lightning and was out of warranty. I don't remember exactly, but I think they sent me a new one for something like $25.

fnfalman wrote:There are Battery Tender Plus and then there are Battery Tender Plus. If you have the old one that was made before the gel battery comes out, then how can you expect the thing to work with your battery? The new Battery Tender Plus not only charges gel but AGM batteries as well. How do I know? I called Deltran, got their advice and bought one for my friend who has a gel battery and his wife's bike has an AGM battery. The unit also says what it's capable of charging right on the box.

In a reply email, the folks at Deltran told me the Battery Tender Plus will not work with the BMW Excide battery. They advised me to purchase the charger made specifically for BMW gel batteries.