Trickle charger overcharging battery?

[chrisntam]

While walking by my 1970 Deville, I noticed water atop the battery. Is this an indication that my charger is overcharging my battery?  Hadn’t noticed this before. Here’s a pic of the charger and of the water.  Car has been in the garage connected to it for prolly two weeks. And no, my roof is not leaking.  Battery is about a year old.

Thoughts?

[Eric DeVirgilis CLC# 8621]

According to an internet search, yes.

Overcharging your battery is another possible way you might cause it to leak. When you charge a battery well past the point required, gases can build up and the battery may burst. An exploding battery may be the worst possible scenario, but you may get leakage or even boil most of the acid out of the battery well.

This is why I do not use so-called "maintenance chargers".

[Lexi]

Eric is correct, but a properly running battery tender should not do that. Unlike regular trickle chargers, they meter what the battery receives based on the state of the battery. I have used a similar product by that same company for many years with never an issue. If they don't self regulate, then yes they will overcharge and boil the battery and cause damage. Sounds like your charger is not working properly. As good as battery tenders are, they still don't take the place of occasional running the car or putting a heavier charger on to keep sulphation levels low. Clay/Lexi

[The Tassie Devil(le)]

Plus, on another note, I see that your battery terminal clamps are not fully engaging the battery posts.

Is there a reason for that?   I always try and maintain full depth contact with battery terminals.

Bruce.

[Eric DeVirgilis CLC# 8621]

The question is when does it stop working correctly...and how long before it's realized so corrective action can be taken?

The possibility of extremely costly damage simply isn't worth the risk for preserving a relatively low cost replacement item in my book. I know of at least one case involving a "battery tender" resulting in a house fire. You couldn't pay me to use one.   

[bcroe]

The question is when does it stop working correctly...and how long before it's realized so corrective action can be taken?

The possibility of extremely costly damage simply isn't worth the risk for preserving a relatively low cost replacement item in my book. I know of at least one case involving a "battery tender" resulting in a house fire. You couldn't pay me to use one.

Trickle chargers not used here, mine have regulated cutoffs. 
Tell us how a battery maintainer could cause a house fire.  Bruce Roe

[Eric DeVirgilis CLC# 8621]

Trickle chargers not used here, mine have regulated cutoffs. 
Tell us how a battery maintainer could cause a house fire.  Bruce Roe

The regulator stopped regulating, overcharging the battery to the point it exploded.

[chrisntam]

Plus, on another note, I see that your battery terminal clamps are not fully engaging the battery posts.

Is there a reason for that?   I always try and maintain full depth contact with battery terminals.

Bruce.

That's about as far as I could get them on.  I suppose I should try again, after I remove the battery and clean up the (potential) mess.

So does everybody not use these?   I just looked up the warranty, 10 years, I have to send it to them for warranty work along with the original receipt, if I have it.

[Eric DeVirgilis CLC# 8621]

That's about as far as I could get them on.  I suppose I should try again, after I remove the battery and clean up the (potential) mess.

So does everybody not use these?   I just looked up the warranty, 10 years, I have to send it to them for warranty work along with the original receipt, if I have it.

You have the evidence before your very eyes of what should not be happening. Now, it's not uncommon for batteries to weep a bit through the vents when being charged (which normally occurs while the car is being driven). This is why it's common to see acid damage under the hoods of cars above and aft of the battery area where it has blown back while driving.

The difference is that air movement of being driven prevents highly explosive acid vapors from building up as would happen when parked- particularly in an enclosed area.

My own garage is an uninsulated pole building, 30x40 with 10.5 feet to the bottom of the rafters with another 4' to the roof peak. So there's plenty of space and ventilation - and even at that, I can still smell the acid vapor when I enter the garage where battery charging had been taking place.

A battery basically becomes a bomb should the conditions be just right. Many use and swear by these so-called battery tenders but ultimately it's up to the individual to weigh the benefits against the risks.



 

[The Tassie Devil(le)]

I use a Battery-Minder in each of my long-standing cars, and never had a problem.   

When using a Trickle Charger, I never leave them connected to a battery after the battery is charged as there is a difference between the two chargers.

Plus, I use the biggest battery that I can fit into the cradle in my cars.

Bruce.

[Mike Josephic CLC #3877]

Hello Chris:

There is something wrong with your Battery Tender.
They contain a microprocessor that is designed to
maintain the charge of your battery within a proper
range of voltage at a maximum charge rate of 3 amps.
It's what they call a "float" level.

Send it back under warranty.

When I worked in a garage many years ago we had
quick charge units that could go at an 80 ampere
rate.  Those you had to keep an eye on.  Yes, I've
seen batteries explode.

I have four Battery Tenders in use 24 / 7 to keep my
car batteries up to snuff.  In 30 years never a problem.

By the way, it's not "explosive acid vapors" that are
the issue.  When a lead / acid battery is charged, the
chemical reaction generates hydrogen gas which can
be explosive under the right conditions (non ventilated
area, source of ignition, etc.).

I'm a retired chemist.

Mike

[dadscad]

I have experienced over charging issues with battery tender products. I usually check the charging voltage every day or so when I have Battery maintainers connected for extended periods. By doing this I found out the battery tender was maintaining at 18+ volts. It should have been 13.4 volts. I have had two deltran battery tenders fail in the same manner.  I have since switched to the battery minder charger/maintainer. I've been using these for several years with reliable performance. I still perform the periodic charging voltage monitor check, just to be sure all is well.

[Glen]

My knee jerk reaction is that 3 amps is way too much for a tender connected for more than a few hours.  But the real concern is the open circuit voltage. 
Open circuit voltage is measured when not connected to anything but the VOM. 

The battery maintainer I have used has an open circuit voltage of 13 volts and short circuit current of 39 mA.

[J. Gomez]

Chris,

I would asked what are the indicators showing while the charger is plug in on the A/C line and the battery?

Have you notice the unit LED indicator cycling while charging and when is fully charge?

These units (at least the good brands) would have safety circuits to detect a minimum voltage at the connection before they will turn-on so there should be no voltage on an open connection or a battery that is below the voltage threshold for the unit to turn-on. They may and could apply maximum power it the voltage is below the normal range to bring it to fully charge and may bring it down to reduced charging once it reaches a full charge.

Discharge of acid water from the battery may be cause by the unit supplying full charge on a full battery, water level on any of the cells banks is too high spilling over while charging, pressure while charging is not properly ventilate forcing the water to spill, etc. etc. 

I have trickle/battery tender charger on my car and occasionally do see small drops of water on top, I just leave the caps on the cells slightly loose if the charger is applying full charge and close them while in the trickle mode, not a problem.

I have the Junior that I use on my wife second car which has the battery on the trunk (it has a vent tube that connects outside) and have had no problems.

Good luck..!

[jdemerson]

Hello Chris:

There is something wrong with your Battery Tender.
They contain a microprocessor that is designed to
maintain the charge of your battery within a proper
range of voltage at a maximum charge rate of 3 amps.
It's what they call a "float" level.

...

I have four Battery Tenders in use 24 / 7 to keep my
car batteries up to snuff.  In 30 years never a problem.

Mike

I have used Battery Tenders  (Deltran brand 12-volt and only 0.75 amp; and VDC brand 6-volt and just 1 amp) for over 25 years on three cars. But my situation may be different from others:

• The batteries are sealed gel-type -- Optima brand inside a Delco case with the Cadillac.
• VDC Battery Minder used on Cadillac for over six years without problems
• Deltran Battery Tender used on other car for over 25 years without problems
• For reasons related to Eric's comments, for the past few years I have only run the Tender and Minder once every four or five weeks (for 24 hours or so) throughout the winter months. The rest of the time it is unplugged and the battery is disconnected. I have an attached garage, so doing it this way has minimal inconvenience.
• My Optima battery in the Cadillac is over nine years old and working fine. In the other car, the batteries have generally lasted five of six years, although the original Panasonic battery lasted eight years.

With our heavily-salted roads, I do not even start the cars from when they are stored until they come out in April. The experiences of other old car owners here in Vermont are generally similar, although most of them leave the Tender connected throughout the winter. I'm perhaps overly cautious, and so Eric's concerns influence my thinking. In any event, over 25 years I've never had a problem, though I know that any product can have a defect.

John Emerson
Middlebury, VT

[cadillac ken]

Eric is correct

I know of two incidents (personally) of faulty battery chargers causing a garage fire.  In one instance the gentleman lost his restored '58 Corvette-- and his garage.

I confess to using the "trickle chargers" but never when I am not home and can check on them.

Regards, Ken

[Lexi]

We are driving cars that if they were people they would be senior citizens with one foot in the grave, or worse. There are risks inherent in all aspects of life and more so with vintage cars when compared to new vehicles. That doesn't stop us from driving them. Everything comes with risks, so our job is to avoid them if possible or at least to mitigate them. Living after all, is dangerous to your health.

The only thing I would add to my earlier post is that if at all possible bring your battery indoors for winter storage, and monitor and maintain it there. In some cases you have to leave the battery in the car as it may have to be started and/or it is stored in such a way that the engine compartment is not accessible in storage, (mine). In that event, using a battery tender is recommended. My car has a traditional wet cell, 3EE 12 v battery, which I have connected to a Deltran 12 v, 1.25 amp Battery Tender Plus. That unit is about 8 years old and was even left under the hood for a season when I had charging issues and was plugging her in each night. So it was subjected to a lot of road shock. It has fell a couple of times onto concrete, (has the dents to show), and it still runs beautifully.

This morning I went out and plugged a voltmeter into the cigarette lighter to see the voltage, (can't open hood as where stored), and found it to be at a steady 13.3 volts, with the Deltran unit operating. That to me, is fine. The unit is doing its job and has been plugged in now for several weeks. I absolutely agree with Dadscad that these units should be checked regularly. No reason to tempt fate. I try to check mine daily, but usually wind up doing so about 3 or 4 times a week, just to see that the green monitor light is on and that there is no heat build up in the unit. Just leaving your battery in and not plugged into a tender? You may still have mice and other vermin to contend with that like to munch on your wiring, but that is another matter.

So, if you cannot bring your battery indoors for long term storage when required, a good quality battery tender is a nice option to have, as long as you are prepared to regularly monitor it. Sadly, in this life nothing comes without a disadvantage, but if precautions and common sense prevail, using one of these units is recommended in some situations. Clay/Lexi

[gkhashem]

I have some cars stored in a garage I cannot get to often. So I disconnect the battery. I have usually been able to hook the car up and start it, usually after sitting 12-14 weeks no problem.

Most of my cars are accessible so I hook them up for a few hours every two-three weeks then shut off the battery with my shut off switch. Then a week or two later come back, switch the battery on and recharge the battery.

[Eric DeVirgilis CLC# 8621]

We are driving cars that if they were people they would be senior citizens with one foot in the grave, or worse. There are risks inherent in all aspects of life and more so with vintage cars when compared to new vehicles. That doesn't stop us from driving them. Everything comes with risks, so our job is to avoid them if possible or at least to mitigate them. Living after all, is dangerous to your health.

Totally agreed with your common sense, long-view perspective and if not keeping a battery "tended" (as it were) over the winter resulted in 100% chance I would be replacing batteries every spring, even I might give it some consideration.

However I've had batteries last for years after being in stored in an unheated building over the winter without ever having needed to use one of these devices. In fact, the el cheapo workhorse battery I installed in my '62 when I first bought it is still in the car and that was ten years ago. And never used a battery tender in all that time.

All I ever did was disconnect one of the battery terminals works for me. Sure they all need to be charged in the spring but that's no big deal.

I would seriously like to know whether there's any statistical evidence supporting the claims of prolonged battery life by the use of these devices. Frankly, I have doubts whether it makes much difference. It is even possible they may shorten battery life.

[TJ Hopland]

I notice that 3amp unit in the photo doesn't seem to have any mention of a maintain mode so I wonder if its maybe not the best choice to be constantly connected?    Even with that said it saying its 'automatic', that should mean its not going to boil out a battery especially with just 3 amps available.   I also have not had the best experiences with that brand.   They are supposed to be the original but that doesn't make em the best.   

Reasons people use them is if they do have anything in the car that is a constant draw like a digital radio or clock.   Saves from having to reset it after disconnecting the battery.   If its an 80's to mid 90's EFI system you would also loose all the 'learned' memory so its not going to start or run as good till it has time to re learn things.  Some people may also not have anywhere better to store a battery other than where the car is being stored so might as well just leave it in the car. 

Climate also makes a difference.   Having a battery sitting at 100*F or higher and below about 20*F for a month will cause some discharge.   I'm not sure what the happens to a weak or dead hot battery but I know for sure they will freeze and 9 times out of 10 you freeze one its not going to come back.  I'm assuming heat must also damage them somehow because hot climate people seem to get less life than us freezing climate people.