Theories....

[franklin2]

Each cell is around 2v. They must have read the voltage on the battery and it was 10v. Even a good dead battery will read close to 12v just sitting there. When you put a load on a good dead battery, that's when the voltage will drop.

That's why you can't really tell the condition of a battery with a regular voltmeter, digital or analog. The meters that will give useful info on a battery's condition are the big chrome ones with the large load resistors inside them.

 

[MIDNIGHT RIDER]

Could I have discovered that myself?

Cells are checked one at a time with a hydrometer and the readings noted and compared.

A difference of ?X? amount in one cell compared to the rest means that is a dead cell.

I don't know the numbers, but every cell must read within a certain range according to the actual temperature at the time.

A hydrometer is that long glass tube gizmo that has a rubber bulb on top and a small hose on the bottom, with a graduated "floater" gizmo inside the clear tube.

You squeeze the bulb and hold it, submerge the hose in the electrolyte, release the bulb, and the chamber fills with electrolyte.

You hold the clear tube vertical and read the number at the "water line".

Squirt the juice back into the exact same hole it came from and test the next one, writing down your findings as you go along.


Why, I do not know; but, it is very important that the juice is never squirted in a cell that it didn't come out of.


When you finish, purge/rinse out the acid with distilled water.


A fully charged battery should yield 2.1-volts per cell; six cells times 2.1-volts = 12.6-volts.

Depending on the alternator/regulator, a battery can read as much as 14- or so volts when first the engine is shut down.

 

[Agnem]

OK well I have one of those hydrometers, but I didn't check every cell. That's good to know. For some reason I was thinking the acid was free to move about in there. NAPA replaced the battery with the bad cell, and so now I have a new one. The other one is being charged, and I will find out today if they think it is salvageable or if that one too shall be replaced. I'm hoping so, because unless I get a new pair, I can't use them in one of my trucks.

 

[f-two-fiddy]

Although this wont help much with Your new batteries, You should do little research on battery desulfating. Seeing as You store Your truck. I do the same, and have found that desufating the batteries gives them a lot longer life.

http://hackaday.com/2009/07/05/battery-desulfator/

 

[WrickM]

Although this wont help much with Your new batteries, You should do little research on battery desulfating. Seeing as You store Your truck. I do the same, and have found that desufating the batteries gives them a lot longer life.

http://hackaday.com/2009/07/05/battery-desulfator/

Mel, actually has a thread about desulfating from years ago, so i am pretty sure he is aware of it at least.

 

[Agnem]

That's correct. Interestingly, the desulfator is one of the ways I can tell my battery tender is working. It runs whenever there is a charge going, so I can actually hear the high frequency noise of the little box under the hood if I tune my ear into it. I just got my 2nd battery back from the NAPA store that was testing it for me. They said it would only hold 2/3 the charge it should have. About 400 amps worth. They said to try and get it replaced which I will do, but due to a screwy situation I have to take it back to the same NAPA I bought them from, which I don't have a problem with since they know me there and can pull up my invoice on the computer. So with any luck, after all this effort I'll have two new batteries. Not sure what I'll put them in right now, but they will end up in something.

 

[MIDNIGHT RIDER]

So far as mixing up batteries of varying ages, brands, and even sizes, I know that it is not recommended, yet I have been doing it for years with no negative issues that I have noticed.

My Ford currently has three batteries all connected, three different brands, varying ages, two are Group-31S and one is an odd-ball of unknown heritage that is too wide to fit in anything else around here; I keep wishing it would give it up so I could get rid of it, yet at over seven years old it keeps going strong.

Sometimes, one battery will go bad and dis-charge the rest.

Once the cables are all off, it is a simple matter to discern which one is the dead soldier; I replace it with a new one and the rest come back to full charge and keep going strong.

 

[franklin2]

Once the cables are all off, it is a simple matter to discern which one is the dead soldier; I replace it with a new one and the rest come back to full charge and keep going strong.

You have to do what's necessary to keep it going, but it's not ideal. The problem is the new battery will never reach it's full potiential because of the older batteries tied to it.

 

[timothyr1014]

x2 on franklins remarks....there are alot of "best practices" which will yeild better results. truth be told, from all of the research I have done the only "real" issues are having one bad cell (think older battery) that takes out others in the bank, the other is if one is grossly undersized, the cabling is not on par for the load and distribution, and the little one gets a sucker punch each time load is applied....

In the cars I am **** stupid about battery maintenance as I dont want the wife stranded somewhere...on the farm equipment, as long as they are within a year of each other I usually call it good.

 

[Titojeep]

Did you check with deltran on your problem? I've been a tender user for years now with no problems. Haveing read your post, I realized that I have yet to use the tender on my truck. I've used it alot over the last few months of ownership, but you bring up a good point. I checked their website, and there's instructions for how to use the battery tender with series or parallel hook up. Just food for thought?

 

[junior20762003]

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".

lmao i just left napa

 

[ericboutin]

I know I'm a day late but I found this very interesting Mel. I was having the same issues with mine. I actually posted about it awhile back. In my case I was actually using the Harbor Freight tenders...I'm glad someone else has had good luck with them......which I can't really say I've had bad luck with them....I am now using it on the TT battery where it is a star! I think the problem lies with the dual batteries. At least that is the conclusion I came up with. I went out and bought one of those "smart" chargers; it's like a tender except it can charge a dead battery also then it becomes a maintainer.....anyway it is bigger but it works much better. I used it on the Dewey this winter and it worked much much better, keeping both batteries charged and ready to go. It has worked much better than the little tenders. I still don't know if it was the dual batts but that was what I came up with or the batteries need to be at absolute full charge before putting a tender on them....I got nothin......

 

[towtruckdave]

Are you sure that desulfater thing is not causing an issue?

 

[MIDNIGHT RIDER]

I think the problem lies with the dual batteries. At least that is the conclusion I came up with.

With anything electronic, weird stuff will sooner or later happen; just ask Toyota.


I have had no issues using a single tender on multiple batteries.

Voltage is voltage; so, the tender sees the whole string of batteries as just one battery.

I could see where if one or more of the paralleled batteries was somewhat under-charged, that a small tender might possibly over-heat during the struggle and burn something out; then, being thus short-circuited, possibly dis-charge the batteries.

Then, on the other hand, I have used a H-F tender to resurrect batteries from the dead and get several more months service from them, with seemingly no harm to the tender.

 

[Willie Two]

Have any of you tried taking a 10 amp or so charger and connecting the positive lead in series with an 1156 light bulb and then to the batteries ? I've been storing my truck all winter long for the past many years using this hook up on the batteries. The 1156 will go brighter and dimmer depending on the required charging rate of the day. 1157 running lite will also work. You can walk by and look at the bulb and it gives you a visual idea of how much of a trickle charge is going into the battery. Batteries never boil and mine have lasted for years. This trick was shown to me by a battery shop years ago.