Theories....

[Agnem]

So I woke the Moose Truck up from its winter slumber last weekend, to take a 2 hour drive to a funeral. I figured it was such a nice day, and a funeral is a drag to go to, that I might as well enjoy the drive as much as possible. So I diconnect the Battery Tender Plus from it, and go to crank it. The dome light was nice and bright when I got in, but as the glow plugs warmed up, the light quickly became dull and by the time they kicked off, there wasn't enough juice to do anything more than engage the starter. That was odd, I thought, since the battery tender had a green light, indicating full charge. Still, I was in my suit and not wanting to take anything else to the funeral, so I jump started it and away we went. I figured something must have been wrong with the battery tender, and the 2 hour drive would charge them up. Not a chance. After the service, I had my own funeral to attend to. A dead Moose, in a parking spot not conducive to jump starting. I noticed on the trip that the volt meter showed a good solid 14 volts, but that the amp meter (which works on my truck) wasn't really showing much of a draw. So after 3 people pushed the truck out into the street, I was able to drift start it and make my way home. On the way home, I stopped and picked up 2 group 31 Interstates and now have them installed. I reflected on the series of events that led up to this. When we went to the rally last year in Bowling Green, I bought the Battery Tender Plus at the Corvette museum gift shop. I had done a lot of reading about batteries and how if they sit a lot it is a real problem, and that keeping one of these on it should fix it up. So I got home, hooked it up and all was good for about a month. Then I noticed a bad smell, and that the tender had died. So I sent it back and got a replacement. While that was happening, I put in a brand new pair of NAPA (Exide brand) batts, figuring that my old Interstates had had enough. "Now..." I thought "with new batts, and a fresh battery tender, these puppies should last a long long time". Not so. The SECOND battery tender also failed (although in a different way... it appeared to be working), and when I got in to crank it, it was dead dead deader than a doornail dead. Soooo... off to Deltran went the second bad battery tender, and it got replaced. I put the NAPA's on life support with a 10 amp charger until I got a full charge indication, and I disconnected that and put the third battery tender on, which brings us up to last weekend. The battery tender had a green light, and by my volt meter indication the batts had a full charge. Obviously though, the battery tender judges charge state by current draw at a certain voltage. The NAPA's were able to fool this battery tender into thinking they were fully charged, and they probably were... but they had no current carrying capacity. This same battery tender is on the new Interstates, and I had a red light for about a day as they brought the new batts up to full charge. I will be taking the NAPA's back for warranty service. I'm befuddled why the NAPA's died in the way they did, and why they would not hold a charge from either the battery tender, or my 130 amp Leece-Neville alternator. I'm going to pop the lids and do a fluid check on them and see what that looks like. I'm open to other ideas, as I would like to know what went wrong. As an aside, if any of you have Superduties, I could use some help here.

 

[WrickM]

sounds to me like the battery tenders are pieces of crap, and that is were i would look for the issue. I mean the batteries are really pretty straight forward and with two known failure of the tenders i would just be strongly inclined to believe the answer lies within that mechanism. I am wondering if the tender didn't tend the batteries as much as just constantly charge them so that overtime the they burn out the batteries. Most batteries like to have some "exercise". Varying volt/amp draws and charges. (though never bringing an auto battery down to zero.) That is just an uneducated guess, but you asked for theories

 

[towtruckdave]

I would junk the tender. D/C the batteries if the truck will be sitting.

As for the fragile batteries, dontcha know NAPA means "need another part already".

 

[dave186]

We have been installing "deadman" switches on all of our farm trucks and have been getting about 3 years out of the batteries in them when they are switched off during the winter. without the switches its new batts every year.

 

[BioFarmer93]

Mel,
You have a current drain somewhere. I'm not positive but I believe it was in a previous post of yours several weeks ago... Didn't you write something about reconnecting the battery and seeing a little spark on contact? If this is the case then something is drawing current. You could go on safari looking for the culprit, or you can just install two disconnects. As far as keeping your batts up, a 5 watt/12V (nominal) solar panel leaning back on the windshield of the Moosetruck with Mr. Moose pointed due south will keep them up to ***** if it's finished snowing up there and you install (and use) the disconnects.

 

[Agnem]

The draw I investigated last year. It's just the stereo equipment and the alarm system. The subwoofer will power up until it notices there is no audio, then it shuts off. After that happens, the draw is at an acceptable level. Disconnecting is not a good option for me. Too much crap to have to set up (clocks... settings...etc). And since I'm in a garage, the sun don't shine there. I have the same product connected to the Lady Moose. I'm keeping an eye on her too. The company that makes the battery tenders has a good reputation, and they stand behind the product. You can't do that for too long if all you make is crap.

 

[BioFarmer93]

Oh.... Never mind.

 

[jperecko]

But I am also thinking that maybe the tenders are not liking that there are 2 batteries... they charge to what they think is full for one battery but there are actually 2

edit- nm on the current draw... maybe the dual batts?... get 2 tenders and hook them up to the batteries after you isolate them?

 

[nyteshades]

With 2 batteries and 1 tender, I would think the opposing battery is drawing power from the battery with tender and the tender can't keep up. Having my bike on a tender when I don't ride, I can say I don't think they do much more than keep the battery topped off. I've had the "green" light on before...and still had trouble cranking the bike.

Not sure how you've wired accessories, but is it possible to deadman the driver side battery and leave the pass battery hooked up to the tender, plus power the clocks, etc?

 

[jim_22]

I think you analyzed it all yourself, you just need the conclusion. Battery tenders nos. 1 and 2 in the process of failing also toasted your batteries (both sets), either by extreme discharge (my guess) or overcharge. Battery tender no, 3 and your truck alternator charged the Napas fully but having already been destroyed they had no capacity (little energy storage). What to do? I don't like to see anything connected to a stored battery, not even a solar charger, because it is a recipe for discharge. If disconnected, the batteries may discharge a few per cent per month. This should be no problem for winter storage to disconnect and do nothing.

 

[timothyr1014]

you said theories...
Thoughts on the first scenario - when I used to build competition audio systems I would see cases all the time where older batteries sat on tenders and would have no problem dealing with a light load over an extended period, but a surge load would knock it to its knees, putting the batteries to actual use seemed to resolve this...make sure that there is some actual fluctuation of voltage & current.

The second time around my money is one battery had a bad cell and took the other with it....faked out the charger and you got a neat chain reaction.

Also, FWIW, keep an eye on your sub, I have seen several that monitor the audio channel (vs remote turn on) that act as you describe...but also will occasionally cycle for no reason...we actually set one car under our time lapse security camera to watch it over night...all told it ran for about an hour in 10 min increments with no one around

 

[sootman73]

You always could just rotate batteries between vehicles that you are driving during the winter and so there would be good loads and re-charging on them...... and if you only disconnect one battery at a time on the Moose truck you wouldn't lose your settings....

just my $.02

 

[jwalterus]

if disconnecting the batteries is not an option simply because you don't want to reset clocks....

why not pull the neg off the pass side battery and leave the drivers side connected?

that way it'll keep everything set, and your drivers side should have enough juice to get you started each spring??

 

[icanfixall]

My wag is the battery tenders are the problem... Its kinda funny how they continue to fail on you... About driving the rig and using the alternater to "charge up" dead batteries... Thats a good way to ruin the alternater... They aren't designed for that. About all they do is recharge the battery after a start and then they power all the accesseries that are running. You might want to run a load test on the alternater just to see if its still operating properly. Was the battery acid level down in any of the dead batteries... If so then I would feel the tender has boiled out the water by overcharging them... Just a theory.....

 

[Agnem]

All good thoughts. Yea, I will be looking at the acid level. My hope is that it is low, and this would confirm the battery tender death idea. Disconnecting one negative is a possibility, but when batteries are in parrallel it is best if their lives mirror each other, which is why they say don't mix old and new. I think if I have to go one more round with this, I'm going to move the batteries to the bed and get some custom cables made. Then I will come up with a way to use a disconnect switch and impliment some kind of off-board based power supply to keep things running. Maybe I should just build a start-cart like the tractor pullers have.