How Not to Charge a Battery

[pglaves]

This sad tale of misadventure is only indirectly related to our BMW motorcycles but it is instructive nonetheless.

I have a Chevy Colorado pickup truck. In said truck I have mounted a GPS. The GPS is powered by a plug in to a cigarette lighter style outlet. This is not switched power. I only drive this pickup every two or three weeks, if that often. Normally we ride bikes or take the car.

So just the other day, after not using the truck for a couple of weeks, we were headed out to some 4WD, high clearance roads in the Big Bend National Park. I went out to start the truck. I turned the key: nothing, no ding, no gong, no instrument lights, and for darn sure no cranking the starter. I had left the GPS turned on and plugged in the last time I used the truck. The truck battery was pretty stone cold run down.

So, I went and got battery charger #1, a good "15 amp charge - 3 amp maintain" charger. The battery was sufficiently dead that this genius of a charger wouldn't start charging the battery. For all its little brain knew it was connected to a chunk of iron or a rock or fence post or something.

Next I went and got charger #2; my 30 year old 2 amp dumb charger. No sophistication here. Hook her up and let her charge. Make sure it is set on 12v and not 6v. I started in the early afternoon. By about 6:00pm I was seeing some sign of battery life: battery voltage was in the upper 10v range. I hooked up my bigger smarter charger #1 and it seemed to take off charging just fine. I decided to let it charge overnight.

In the morning the charger was found to have quit trying and battery voltage was down to 3 volts something. Oh, no, the battery is shot. Oh well, I'll get a new one in town next week. Live and learn I told myself.

After a while for a totally unrelated reason I needed but couldn't find my truck keys. When I looked in the truck the keys were there and the ignition key was in the TURNED ON position. I had been charging the battery with the ignition key in the "ON" position. During the day it gained some, but this truck also has "smart" headlights, and in the "Auto" setting the headlights and tail lights and such come on when it gets dark. Or at least they try to do so.

So voila - the genius owner is trying to charge a battery with the truck key on, and the automatic headlights trying to come on every now and then if the voltage got high enough. The end result is that the smart charger gave up and quit, and the key-on truck ran the battery back down even more.

I have a simple suggestion. Don't do this. Not on your car, your truck or your motorcycle.

After carefully analyzing the situation I retrieved my keys from the truck, thus leaving the things/stuff turned off. After several hours the charger dropped out of charging mode and lapsed into maintenance mode. Battery voltage one hour after I unhooked the charger was 12.9 volts. A couple of hours later the truck started just fine. Maybe the battery is going to survive its owner abuse. I hope.

All expressions of sincere sympathy, and even energetic guffaws are graciously accepted.

 

[52184]

Dang, I hate it when I do stuff like that!

Glad you got your battery revived! You are not alone in having that sort of “shoot yourself in the foot” experience. I’m betting we all have a tale or two like that in our past.

Best,
DeVern

 

[Omega Man]

Happy you found your keys
OM

 

[stevenrankin]

Yep

I won't throw a rock, but sorry, I can't help but laughing. Very glad you got things worked out. Remember it could have been worse. You could have had a BMW car instead of a GMC truck. At least on the truck you can see the battery, LOL. Merry Christmas Paul and Voni. St.

 

[langoptc]

On the plus side, you didn't incur any out of pocket expense!

 

[mikegalbicka]

My Duh! moments are getting more frequent but not any less surprising. Even if I anticipate them they can still happen because I didn’t follow the thought through with action quick enough.

Getting old is not for the faint of heart.

Always provides a good laugh though.

 

[brownie0486]

Leave the truck on trickle charge when not in use if it's not used for a length of time?

 

[rogerc60]

Uh oh

Uh oh, I chuckled at this. Now I wonder what brain-dead thing I'm going to do this week.

 

[riderr1150gsadv]

I think we all have those 'senior' moments in life.... At least you have your keys...

 

[pglaves]

Leave the truck on trickle charge when not in use if it's not used for a length of time?

I do when we leave for a month or two but not when I am driving it every two or three weeks. I just need to not leave the GPS plugged in.

 

[BC1100S]

That battery of yours seems to be able to absorb a lot of abuse. Who makes it?

 

[gregfeeler]

This sad tale of misadventure is only indirectly related to our BMW motorcycles but it is instructive nonetheless.

I have a Chevy Colorado pickup truck. In said truck I have mounted a GPS. The GPS is powered by a plug in to a cigarette lighter style outlet. This is not switched power. I only drive this pickup every two or three weeks, if that often. Normally we ride bikes or take the car.

So just the other day, after not using the truck for a couple of weeks, we were headed out to some 4WD, high clearance roads in the Big Bend National Park. I went out to start the truck. I turned the key: nothing, no ding, no gong, no instrument lights, and for darn sure no cranking the starter. I had left the GPS turned on and plugged in the last time I used the truck. The truck battery was pretty stone cold run down.

So, I went and got battery charger #1, a good "15 amp charge - 3 amp maintain" charger. The battery was sufficiently dead that this genius of a charger wouldn't start charging the battery. For all its little brain knew it was connected to a chunk of iron or a rock or fence post or something.

Next I went and got charger #2; my 30 year old 2 amp dumb charger. No sophistication here. Hook her up and let her charge. Make sure it is set on 12v and not 6v. I started in the early afternoon. By about 6:00pm I was seeing some sign of battery life: battery voltage was in the upper 10v range. I hooked up my bigger smarter charger #1 and it seemed to take off charging just fine. I decided to let it charge overnight.

In the morning the charger was found to have quit trying and battery voltage was down to 3 volts something. Oh, no, the battery is shot. Oh well, I'll get a new one in town next week. Live and learn I told myself.

After a while for a totally unrelated reason I needed but couldn't find my truck keys. When I looked in the truck the keys were there and the ignition key was in the TURNED ON position. I had been charging the battery with the ignition key in the "ON" position. During the day it gained some, but this truck also has "smart" headlights, and in the "Auto" setting the headlights and tail lights and such come on when it gets dark. Or at least they try to do so.

So voila - the genius owner is trying to charge a battery with the truck key on, and the automatic headlights trying to come on every now and then if the voltage got high enough. The end result is that the smart charger gave up and quit, and the key-on truck ran the battery back down even more.

I have a simple suggestion. Don't do this. Not on your car, your truck or your motorcycle.

After carefully analyzing the situation I retrieved my keys from the truck, thus leaving the things/stuff turned off. After several hours the charger dropped out of charging mode and lapsed into maintenance mode. Battery voltage one hour after I unhooked the charger was 12.9 volts. A couple of hours later the truck started just fine. Maybe the battery is going to survive its owner abuse. I hope.

All expressions of sincere sympathy, and even energetic guffaws are graciously accepted.

Paul,
I can't beat that story, but can come close. My fiancé has a Subaru Forester which has a fore/aft rocker switch for the parking lights on the top of the steering column. It's very hard to see, and it seems the people at the car wash she goes to inevitably turn it on by accident when wiping down the inside of the car. These lights stay on with the key off, so the first time this happened the battery was stone dead the next morning. I put on the big charger and after what seemed like a long time it did complete and all seemed well. She drives the car that day just fine, but the next morning the battery is dead. Now I either have a very bad battery or some other problem, and after a search found this GD switch. It's now the first thing she checks after the car wash.

 

[brownie0486]

I do when we leave for a month or two but not when I am driving it every two or three weeks. I just need to not leave the GPS plugged in.

 

[pglaves]

That battery of yours seems to be able to absorb a lot of abuse. Who makes it?

It is a Duralast which is a house brand at Auto Zone.

 

[gregfeeler]

It is a Duralast which is a house brand at Auto Zone.

Back to my fiancé's Forester, it had a year old Duralast Gold battery as of Saturday. In the dark months here, she has left a map light on twice in the last two months. The second time was the past Friday night and even after a good, long charge process which showed as being completed, the battery didn't hold a bit of charge after a couple of hours. AutoZone was good about honoring the 3-year warranty. However, when there was still a Sears store here I used Diehard batteries in that vehicle and they just would not die. I know that one was run flat by the parking light/map light trick at least four times and it still lasted almost eight years. Not data, but personal experience.

 

[pglaves]

Back to my fiancé's Forester, it had a year old Duralast Gold battery as of Saturday. In the dark months here, she has left a map light on twice in the last two months. The second time was the past Friday night and even after a good, long charge process which showed as being completed, the battery didn't hold a bit of charge after a couple of hours. AutoZone was good about honoring the 3-year warranty. However, when there was still a Sears store here I used Diehard batteries in that vehicle and they just would not die. I know that one was run flat by the parking light/map light trick at least four times and it still lasted almost eight years. Not data, but personal experience.

Most car/truck batteries are not deep cycle batteries, and don't appreciate being abused the way I did it. I think I lucked out (so far).

 

[gregfeeler]

Most car/truck batteries are not deep cycle batteries, and don't appreciate being abused the way I did it. I think I lucked out (so far).

Agreed. In fact, on last Saturday morning after removing the charger, I wondered how much longer that bettery would last. I didn't have to wait long to find out.

 

[stevenrankin]

At least

Look at it also Paul, you had a good charger on hand, things might have been different with a cheap one. St.

 

[senseamidmadness]

Definitely a relatable story.

One of the biggest reasons I opted to spend more money on my Oilhead heated grip system by buying OEM was because of idiot-proofing. My last bike, a 2002 Kawasaki Concours, had a pair of typical wired-straight-to-the-battery grip heaters with only a small rocker switch to control them. So as long as the switch was on and the battery had juice they'd try to get hot.
In the four months I owned that bike I killed the battery two separate times by forgetting to turn the grips off after a ride. Having a spare battery around for that thing was really useful.
I am so happy that the BMW grip heaters on my bike will not turn on unless the bike is on. One less potentially frustrating thing to forget!

 

[akbeemer]

Here’s how I see it, or at least how I would try to sell this set of circumstances to Annie:

1. Conducted long-term test of GPS. All okay.
3. Conducted field test of “Genius” charger to establish the limits of said genius. Limits established; no longer referred to as Genius.
5. Conducted second field test of charger number 2 and confirmed genius is not all it is cracked up to be: sometimes a dumb guy with a hammer gets the job done.
7. Tested the light control system of the truck in a long-term simulated operational test. Established that the system got its brains the same place as the genius charger.
9. Ran rigorous operational test of the truck battery by putting it through multiple total loss scenarios. Battery performed well, although life expectancy is now suspect, and the test continues.

I see a return to the Owner’s News for a guest article recounting tour exploits.