battery tender question

[jbum]

i left my battery tender (schumacher SE-1-12S) attached to the battery of my nsx for 2+ months. I tried to start it and I just heard a bunch of rapid clicks. Well, the battery wasn't holding charge. I measured it immediately and it only registered 11.9V on my DMM.

When I took the battery out, I noticed a bulge on the side walls. The guy at Kragen noticed that and said it probably got overcharged.

At what voltage does the tender stop charging for a standard 12V car battery?
I noticed that the "charged" light was never on when I checked it in the last month or so...

Is it possible that the battery was just bad (it was drained a couple of times in the last 2+ years because I forgot to put the tender on then) and it just wasn't holding the charge?

Could the tender almost be bad? is there a good way to test for it?

Thanks,
jbum

 

[Briank]

Could the tender almost be bad? is there a good way to test for it?

Thanks,
jbum

I guess it could be bad, replace the battery and monitor the battery with a volt meter for a couple of days with the charger on. You should not see much more then 14.8v or so. It could also have a bad diode in the charger that is letting AC through to the battery and lead acid batterys don't like AC. You may be able to check for AC with your volt meter set to AC but a new battery may mask the problem.

 

[KooLaid]

Battery was probably bad before you even threw the charger on. I've had a battery buldge on my truck before and it never saw a charger in the years of it's life.

Then again I'm not sure what exactly causes the buldging and BrianK is the electronic whiz.

 

[Malibu Rapper]

Per the manual description below, it stops charging around 14v and starts charging when it drops down to 13v.

Red On Battery charger voltage is approximately 14 volts and charging has stopped.
Red Off Battery voltage has dropped one volt and the charging has resumed.

You will want to check the voltage at which the Schumacher charger stops charging as it could be overcharging the battery and causing it to gas.

A Battery Tender as your thread title specifies is a device made by Deltran Corp, something that a lot of us on Prime use and swear by. Ken, D'Ecosse turned me onto it and there is a good thread about it here. It charges the battery and then has a maintenance voltage at 13.2v that doesn't cycle. Here are a couple useful tidbits of information from their website.

4. How is the Battery Tender Plus battery charger different from a trickle charger?

The Battery Tender Plus battery charger delivers 1.25 amperes during bulk charge mode, holds the battery charge voltage constant at 14.4 VDC during absorption charge mode until the battery charge current drops to 0.1 amperes at which time it then automatically switches to a float charge mode. During float charge mode, the output voltage of the Battery Tender Plus battery charger is 13.2 VDC, which is well below the gassing voltage of a lead acid battery. This keeps the battery topped off, while minimizing any detrimental effects to do gassing. The Battery Tender Plus battery charger is able to perform these complex switching functions because its electronic circuitry is controlled by an on board microprocessor.
Although they often appear to be a better economic choice for the typical consumer, trickle chargers do not have the advantage of sophisticated electronic control. Therefore, as they allow the value of charge current to trickle down to what appears to be safe levels, the output voltage of the charger rises well above 15 VDC, sometimes even going higher that 16 VDC depending on the charger type and the battery that is connected to it. Either voltage is well above the gassing voltage of a lead acid battery. If the battery remains connected to this high level of voltage for an extended period of time, even less than 1 day, extreme damage can be done to the battery. What appears to be a cost savings for the charger may actually cost several times the charger price in replacement batteries.

6. What makes the Battery Tender Plus battery charger different from other automatic battery chargers?

Many automatic battery chargers turn off when the battery voltage rises or the charge current falls to a preset level. Then after a period of time, when the battery self discharge characteristics have reduced its terminal voltage significantly, sometimes to the point where the battery has given up almost 90% of its stored charge, the charger will turn on and recharge the battery. This type of cycling will dramatically reduce battery life. The Battery Tender Plus battery charger does not turn off. It automatically switches to a safe float voltage level that keeps the battery charged and yet does not do any harm to the battery or cause any reduction in its useful life.

 

[kreh]

Battery was bad. I have had similar experience.

 

[Acura NsX Pilot]

I would just check the voltage output of the battery tender before you but it on the new battery with the DMM.

 

[nsxtasy]

I've been using that same model of battery charger since 1991 (same unit, never replaced), for 4-6 months each winter and most of the rest of the year, and I have never had any problems whatsoever.

In fact, I replaced my battery twice during that period - the stock battery after 6 years and a lightweight Black Panther after 8 - not because either one died, but just as a preventive measure. For all I know, both could have lasted years longer.

 

[PhiAlpha44]

I swear by Battery Tenders too. I keep one on both my motorcycles, My Fiero GT, my NSX and my Riding Mower all winter long, and also plug in my pick up truck at times just to keep her good and "juiced" up. I've never had a problem with any of them, I've been doing it for 3 years.

 

[jbum]

I tihnk just to be safe, I'm going to keep it on only for a few days... and hopefully drive the car once a week.

Been neglecting it cuz of possibilities of rain...

 

[OLDMNSX]

Just a side note here, if you need to replace the battery and don't want a lightweight/high tech battery buy a INTERSTATE battery. They have a 18 month FREE replacement, none of that prorated stuff. I stay away from Exide batteries. I have had bad luck with them, many times.

If you want to see what the manufacturer thinks of their batteries, just look at their warranty. That tells the story.

Brad

 

[Malibu Rapper]

Just a side note here, if you need to replace the battery and don't want a lightweight/high tech battery buy a INTERSTATE battery. They have a 18 month FREE replacement, none of that prorated stuff. I stay away from Exide batteries. I have had bad luck with them, many times.

If you want to see what the manufacturer thinks of their batteries, just look at their warranty. That tells the story.

This is true about the warranties. Exide actually has their Marathon and Nascar batteries that come with a 40 month free replacement, 108 month prorated. The Orbital Select and XCDs all come with 18 month free replacement as well.

 

[Joe Gliksman]

I had the same thing this weekend. Even with the charger, the battery would not hold a charge. Took it back to Wal-mart and got another free one--this one was 28 months old. THey have free replacement for 36 months--which is amazing to me. I only started using the battery tender when it the old battery started giving me problems.

 

[kaz1116]

I tihnk just to be safe, I'm going to keep it on only for a few days... and hopefully drive the car once a week.

Been neglecting it cuz of possibilities of rain...

i wish i had that option
its all snow on the ground here and it doesnt look like ill have a chance to drive it anywhere soon

mine just did the same thing as well and about an hour ago i hooked up a trickle charger to it
ill leave it for a few days then what can i do in my case to see if its holding charge , without overcharging it?

 

[nsxtasy]

Just a side note here, if you need to replace the battery and don't want a lightweight/high tech battery buy a INTERSTATE battery. They have a 18 month FREE replacement, none of that prorated stuff. I stay away from Exide batteries. I have had bad luck with them, many times.

If you want to see what the manufacturer thinks of their batteries, just look at their warranty. That tells the story.

You can do better. Most of the top-of-the-line batteries offer longer batteries than that, usually 24-36 months of free replacement, along with the longer pro-rated period. MR mentioned one with 40 months.

The best deal in a conventional size battery is at Costco. Their batteries are sold under their Kirkland house brand and are made by Johnson Controls, one of the top battery manufacturers. They have lots of cold cranking amps and come with a warranty with 36 months free replacement and 100 months pro-rated. If you shop around, you'll find that they're substantially lower in cost than similar batteries anywhere else (even Sam's Club and Wal-Mart).

 

[COS91BB]

Sorry for this late reply but I have a question about the Deltran Battery Tender Plus. The install instructions wants the (-) negative ring terminal attached to a chassis ground and not the negative terminal on the battery. Has anyone found a good chassis ground for this terminal? The jumper harness isn’t very long so the options are limited.

Found this thread on a search and decided to try this thread instead of starting a similar one.

Any help would be appreciated.

Thanks

Dave

 

[TyraNSX]

Post #61 here

I have mine set up this way. Neg ring terminal to bolt on outboard side of fuse panel, pos. ring terminal carefully follows the cable coming into the fuse panel from the pos. battery cable and attaches to the same terminal. Looks factory if you route it neatly. The pigtail is short. I slide the cable from Batt. Tender under the car so I can see it by lower radiator hose, then reach down & pull it up to plug in. I don't advise doing this when car is hot. Ask me why. Only down side is you need to pop the hood to connect/disconnect, but I consider it a small price to pay for not having a dead battery in 4-5 wks. Be sure to tuck the pigtail out of way behind wires by fuse panel before driving so it doesn't end up in the fan or something else moving.

 

[COS91BB]

Thanks TyraNSX for the suggestion and link to the other post. I’ll give that a try.
Colorado Springs usually prides itself on mild winters and short snow cover so the battery has never been a problem. This winter is by far the exception. The snow is finally gone but now we are pothole city. I’m not sure when I’ll risk getting the car out again.

Dave