Battery Charger Experiment

[Semper_Fi]

Did a very loose experiment the last couple of days.

 

I have been putting the bike on charge at the end of the day (using the front accesory socket)

 

I am following the BMW Charger instructions and the lights blink accordingly - on the following morning it is all green - life is good.

 

Wednesday - I set it up to charge as always and intentionlly left the grips on high (i have been diligent in shutting down the seat and grips if used). When I checked the bike Thursday morning the charger only registered to yellow (2/3) - bike fired up fine and off to work

 

Thursday night I set the bike to charge and this time all was off again and in the morning the charger showed green.

 

Question - why would the bike not charge all the way if the grips were on? I may try this again with the grips and seat on to see if it even makes it to 2/3's - I did not notice if the grips were warm.

 

Curious

[smiller]

The battery charger probably can't generate enough current to operate the heated grips and charge the battery, maybe not even enough for the grips alone. If so, with the grips turned on your battery would have eventually gone completely flat even with the charger attached.

[Semper_Fi]

smiller - are you saying that if i leave the grips on, for example, and the bike off and leave it like that for a week (hypothetical time frame) the battery will be flat?

 

Or that with the charger and the magical CANBUS the grips are turned on?

[krussell]

I don't get this. At first glance I would say that leaving the grips on means nothing. I assume grips on = grip heat switch on, key off. The grips would actually not heat. Are you saying with the grip switch on, key off, that the grips are actually drawing current. My take is that is a defect.

 

If you are saying grips on, key on, then I would expect that the charger would not be able to keep up with the current draw of the grips.

 

I don't have a charger, I haven't seen a need yet. I typically ride weekly, and often am riding with grips and seats on. The bike seems to keep the battery well enough to endure the breaks between riding. The longest I've gone without riding is about two weeks, it ran just fine. I am only at 3500 mi, so I may just be lucky.

[smiller]

If you leave the grips turned on for a week then you will kill the battery for sure. I don't understand the second question, and I would also question whether CANBUS would allow you to have the grips on when the ignition is off? Not sure I understand that part either.

 

BTW leaving a significant load on while charging the battery will create problems even if the charger has adequate power to run everything because a modern 3-stage charger is also monitoring current draw to determine when the battery is reaching a specific charge level. If you have some accessory on at the same time drawing a lot of current the charger will likely be fooled and stay in the absorbtion charge mode too long, overcharging the battery.

[Semper_Fi]

Sorry for not explaing correctly.

 

Charger on, Key off, Grips left on - charger light yellow

- is this because with charger on it "sees" the grip load and tries to support?

 

Charger on, Key off, Grips off - charger light green

- no question understood

 

Question

 

No charger, Key off, Grips on or seat on - will the battery be discharged in a short period of time

 

Luis

[R4ND0M_AX3]

I thought I read something about the magic charger simulating use or something. I've seen it green for several days in a row then have seen it drop to 2/3 yellow.

[Semper_Fi]

...the magic charger .....

 

too funny

 

don't mean to start a potential "oil" thread with the charger - just was curious on the actions it does.

 

Will charge with everything off - seems to be the best solution

[krussell]

No charger, Key off, Grips on or seat on - will the battery be discharged in a short period of time

 

Ok, this one I understand. :-)

 

For the first 60 days and 2500 miles of owning my RT I never turned off the seat or the grips while the bike was off, or on for that matter. My battery was fine. I don't know the current draw of either, but suspect if they stayed on it would not last overnight.

[Semper_Fi]

From my very limited knowledge of the RT - the grips and the seat do not actually warm up unless the bike is running.

 

For charging that appears to be a different subject.....

[Boffin]

With the "magic charger" connected using the correct sequence, the ZFE module leaves the accessory sockets switched on, allowing charging to take place. I suspect, from your description of the symptoms, that this causes power to be available for the heated grips as well. If that is the case, then it is at the very least an oversight in the manual to not tell the owners about it.

I wonder how many of the "failure to charge the battery" issues we have seen here are related to this?

 

Andy

[tallman]

Andy,

Certainly you're not suggesting that it is possible for a user generated error to occur.

It has to be the bike's fault.

[99Roadster]

As mentioned the charger will cycle through all phases of charging on occassion.

 

My RT has been on the charger since late December (when will this snow ever melt ) and in that time I have seen it cycle three times at different phases eventually returning to 3/3. It may have been more without me noticing.

 

I don't know about the heated grips but if they are able to stay on with the charger connected this would be bad. Are they actually heating?

[Semper_Fi]

As mentioned the charger will cycle through all phases of charging on occassion.

 

My RT has been on the charger since late December (when will this snow ever melt ) and in that time I have seen it cycle three times at different phases eventually returning to 3/3. It may have been more without me noticing.

 

I don't know about the heated grips but if they are able to stay on with the charger connected this would be bad. Are they actually heating?

 

When I noticed the 2/3's light i did not check the grips.

 

For sh$ts and grins I can try tonight and see what happens?

[Semper_Fi]

[For sh$ts and grins I can try tonight and see what happens?

 

I just set the bike up for charge with the grips on max, left it like that for about 15 minutes - grips were at ambient - shut off the grips and put her to bed.

[VinnyR11]

If you leave the grips turned on for a week then you will kill the battery for sure.

 

Not sure this is always correct. On my bike, R11RT, when the key is off the grips don't draw nor get warm. I can leave them on with the key off and the battery will not drain. Similar to a radio, heater fan motor, etc. on a car. Seems to me that the design should be key off, accessories off. (Other than very low draw clock or others). Maybe it's different on the newer bikes, but I don't know why BMW would do that.

[99Roadster]

Sounds like you should see 3/3 soon if not already.

[steveknapp]

With the "magic charger" connected using the correct sequence, the ZFE module leaves the accessory sockets switched on, allowing charging to take place. I suspect, from your description of the symptoms, that this causes power to be available for the heated grips as well. If that is the case, then it is at the very least an oversight in the manual to not tell the owners about it.

I wonder how many of the "failure to charge the battery" issues we have seen here are related to this?

 

Andy

 

Bingo. The "magic" CANBus and ZFE is really nothing more than a high-tech relay/fuse box and wiring harness.

 

The bike turns the circuit with the power outlets off when the bike is off. UNLESS the charger is connected, then that whole circuit is left on. Sounds like the heated grips are left on, or at least something in the ZFE remains more active in that state.

 

I'm not sure why BMW is playing all the games to allow the charger to charge via the accessory socket. It's like some junior member of the staff got the spec and said "OK" ignoring how absurd it is (Stonehenge, Spinal Tap..) then went off to create what you've got now.

 

The bike only needs the charger for extended storage (weeks), and any battery charger keeps it happy if connected directly to the battery. Well, any but the BMW charger which had issues charging the battery outside the bike for me.

 

Put the BMW charger up for sale, buy a Battery Tender.