Battery Charger/Maintainer-Battery Question?

[Sayjac]

Son has the Advance Auto version of the Schumacher SEM-1562A-CA 1.5 Amp Speed Charge Battery Maintainer. Same charger just labeled Autocraft Charger/Maintainer. Used it this past weekend to charge an Audi OEM battery, said it took ~12hrs to get the fully charged green light. First time the battery had been charged, but was having no starting/cranking issues. In my experience with low amp slow charge maintainer (like Battery Tender Jr) didn't seem out of the ordinary.

Reading the charger/maintainer literature I noticed this in the instructions. "The Schumacher SEM-1562A is a battery maintainer, and maintains both 6 and 12 volt batteries, keeping them at full charge. It can charge small batteries and maintain both small and large batteries. If you are maintaining a fully charged large battery, you will be properly utilizing the battery charger. However, if you use the battery charger to charge a large battery, such as a marine deep cycle battery, that was not fully charged, you may lose some of the battery’s capacity. This would cause the large battery to be unable to hold a charge and become useless. Therefore, we do not recommend charging a large battery with this unit." It does however show a desulfation mode.

So the question is, can using this charger/maintainer (or any low amp charger/maintainer) actually reduce the battery capacity or life, specifically of a not fully charged but not dead auto battery?

Below are links to the Schumacher Charger on Amazon and the pdf instructions. You may notice the charge chart on Amazon differs from the instructions. Larger batteries show 'maintain' in pdf.

What say you battery charger experts?

http://www.amazon.com/Schumacher-SEM-1562A-CA-Charge-Battery-Maintainer/dp/B0009IBJAS

http://www.batterychargers.com/content/pdf/0099001192WB-00.pdf

 

[horse123]

Is he using a deep cycle battery that's significantly discharged?

 

[Sayjac]

I don't believe it's a deep cycle, whatever the Audi oem battery is. Afaik, it's a standard automotive battery.

However I did read that it says, 'such as' a marine deep cycle battery'. That implied 'to me' that was an example of one type of "large battery".

 

[Donald]

Some maintainers "time" the charge and if the battery does not get to 100% in 24 hours they stop, as they do not want to blow up a bad battery.

I would get a 8 to 15 amp charger for actual charging and use the maintainers for maintaining.

 

[Quattro Pete]

http://www.geniuschargers.com/products

I was checking out these Noco chargers, based on a recommendation from an earlier thread. Bottom part of this page has a comparison chart. Looks like either the G3500 or G7200 would work well for a car battery, both as a charger and as a maintainer. The G7200 would offer a quicker charge at 7.2A, but the G3500 does have a "small battery" support, if you need it. If it's just for a car battery, I'd probably go with the G7200.

 

[Sayjac]

So looking at the Noco chart it appears that a somewhat higher amp charger is more ideal than lower amp, at least for charging. Interesting.

Just wondering if occasional use of lower than the 3.5 amps, would actually shorten the battery life? Perhaps depends on how often the maintainer is used?

The Noco G3500 looks good.

 

[razel]

If it is a true battery maintainer (usually called smart) then using it will not shorten the life of a battery. Dumb battery maintainers are also ok as long as you keep battery temperature and acid levels in check, which the average person won't do.

In fact, one method to desulfate/condition a battery is to remove all the acid, put distilled water in. Charge until full or/and temperate is too hot, and/or water-acid's specific gravity stops rising.

Also don't fret over amps. Your battery will take whatever amps it wants. Once it reaches the max amp your charger is designed for it often just stresses your charger. The battery minder I have is 1.5 amps and is specifically NOT recommended for bulk charging batteries. You certainly can use it, but it will not last very long for industrial charging duties.

 

[y_p_w]

I've got one of these myself. However, I've never really used it to try to charge a battery where it would cut out because it didn't get to a fully charged state by the timeout period. I did lend it to a friend once because jump starting didn't seem to work given short trips (it would need another jump). I think it was used for a few hours, and by that time there was enough charge to perform multiple starts and they drove it a while over the weekend.

I think "damage" is kind of a strong word. It's not the ideal use. If I had a depleted large battery, I'd probably use my 12 amp Schumacher, which should charge up almost anything in less than 12 hours. However, the 1.5 amp unity shouldn't be too bad if it can fully charge before auto timeout. I don't believe it really burns itself out since it effectively charge limits itself, and the state of the battery won't kill it.

I also have the previous version of the 1.5 amp Schumacher. That one has a manual 6/12 volt switch, but doesn't claim polarity or short protection. I think it's all analog and won't do any of the fancy stuff like timeouts or desulfation. It's also heavier with a traditional coil power supply, rather than a switching power supply.

 

[Quattro Pete]

Originally Posted By: razel
The battery minder I have is 1.5 amps and is specifically NOT recommended for bulk charging batteries.

What would you recommend as far as minimum Amperage for bulk charging of car batteries?

 

[y_p_w]

Originally Posted By: Quattro Pete
Originally Posted By: razel
The battery minder I have is 1.5 amps and is specifically NOT recommended for bulk charging batteries.

What would you recommend as far as minimum Amperage for bulk charging of car batteries?

The one I would use is 3/12 amp selectable. Once the battery is fully charged it automatically goes into maintain mode using the 3 amp setting when it does charge. My understanding is that with these new "microprocessor controlled" chargers, the general action is to shut off and monitor rather than constantly place some trickle charge.

 

[razel]

Originally Posted By: Quattro Pete
Originally Posted By: razel
The battery minder I have is 1.5 amps and is specifically NOT recommended for bulk charging batteries.

What would you recommend as far as minimum Amperage for bulk charging of car batteries?


Unless you are a car dealership with a fleet of cars, if you want to bulk charge a nearly dead battery, for nearly everyone, just use your car's alternator. Go for a scenic drive to visit someplace new out of the way maybe 45 mins one way on the highway. Then when you return use your maintainer to top it off. When you do return, you'll need to let the battery rest. Not just to remove the surface charge, but also to let it cool.

 

[Robenstein]

Originally Posted By: sayjac
I don't believe it's a deep cycle, whatever the Audi oem battery is. Afaik, it's a standard automotive battery.

However I did read that it says, 'such as' a marine deep cycle battery'. That implied 'to me' that was an example of one type of "large battery".


Deep Cycle batteries are not used in cars. They don't have the cranking amps needed. Your AUDI battery is not a deep cycle.

 

[Quattro Pete]

I don't know what it is about my 530i, but the battery never gets fully charged, even after extended driving. My charger/maintainer always reports that it's undercharged and will charge it for quite some time before it considers it full.

I've got a fairly new alternator in it, but I'm not sure how to verify that it's working as it's supposed to. No error codes.

Then there is the extreme short tripping that doesn't help either.

 

[Sayjac]

Thanks to all for the contributions and thoughts. After I read some more in the instructions I saw where as y_p_w noted if the battery didn't finish charging somewhere around 12hrs it would go into an abort mode. So thinking while this charger might not be ideal for severely discharged large battery, likely ok (no damage) for anything else. I'd imagine if he tries it again the charge period would be significantly less. Going to recommend he use it more often now.

Think vehicle is used mostly for shorter tripping but not extreme.

 

[Quattro Pete]

Originally Posted By: Quattro Pete
I don't know what it is about my 530i, but the battery never gets fully charged, even after extended driving. My charger/maintainer always reports that it's undercharged and will charge it for quite some time before it considers it full.

I've got a fairly new alternator in it, but I'm not sure how to verify that it's working as it's supposed to. No error codes.

Then there is the extreme short tripping that doesn't help either.

Responding to myself at this point, but just FYI, it took about 8 hours for my 2 Amp BatteryMinder to bring the battery back up to full charge yesterday. The last time I had it hooked up to this charger/maintainer was about 2 months ago. The last two months included primarily short trips with a couple of slightly longer trips (30 mins each or so).

 

[Sayjac]

Originally Posted By: Quattro Pete
..Responding to myself at this point, but just FYI, it took about 8 hours for my 2 Amp BatteryMinder to bring the battery back up to full charge yesterday. The last time I had it hooked up to this charger/maintainer was about 2 months ago. The last two months included primarily short trips with a couple of slightly longer trips (30 mins each or so).

Good information as comparison to the topic'd Schumacher charger/maintainer first time experience. Thanks.

 

[Quattro Pete]

Also just FYI, here is the basic logic (including time limits) that this BatteryMinder applies:

 

[y_p_w]

Originally Posted By: sayjac
Thanks to all for the contributions and thoughts. After I read some more in the instructions I saw where as y_p_w noted if the battery didn't finish charging somewhere around 12hrs it would go into an abort mode. So thinking while this charger might not be ideal for severely discharged large battery, likely ok (no damage) for anything else. I'd imagine if he tries it again the charge period would be significantly less. Going to recommend he use it more often now.

Think vehicle is used mostly for shorter tripping but not extreme.

Yeah - it's not going to kill the battery or catch on fire from overload/overuse. However, it's got a specific use, which is to maintain car batteries or charge small batteries.

This is what I use when I need to charge a depleted battery:

http://www.amazon.com/Schumacher-SC-1200A-CA-SpeedCharge-Maintainer/dp/B000BQSIWK

The description that it has a 6 amp selectable current is incorrect though.

 

[y_p_w]

Originally Posted By: razel
Originally Posted By: Quattro Pete
Originally Posted By: razel
The battery minder I have is 1.5 amps and is specifically NOT recommended for bulk charging batteries.

What would you recommend as far as minimum Amperage for bulk charging of car batteries?


Unless you are a car dealership with a fleet of cars, if you want to bulk charge a nearly dead battery, for nearly everyone, just use your car's alternator. Go for a scenic drive to visit someplace new out of the way maybe 45 mins one way on the highway. Then when you return use your maintainer to top it off. When you do return, you'll need to let the battery rest. Not just to remove the surface charge, but also to let it cool.

That is not the best way - not by a longshot. Certainly if you've got to go somewhere and just had someone jump start your car, there may not be any other options other than to drive for a while to give the battery enough charge to start again. However, it's tough on an alternator to do that. I can't think of any mechanic who would recommend doing that if a charger that plugs into AC were available. Heck - even the 1.5 amp maintainer until it shuts off would be preferable. The toughest duty for an alternator is to charge up a depleted battery, and in any case they're not terribly advanced like a modern charger. It's helpful for the charging rate to be limited for a while. I've even heard some suggestions using a jump starter to keep it attached for a few minutes to absorb some of the charge from the alternator.

If I was stuck having to jump start my battery, I'd just drive home, get my car into my garage, and charge with the $30 3/12 amp Schumacher charger I bought a couple of years ago. Also - my wife drives a lot of short trips, and I attach the 1.5 amp maintainer every once in a while to keep the battery from degrading.

 

[RoadRaceJosh]

The reason a slow charge can harm a battery is that the lead sulfate of a deeply discharged battery can reform into lead crystals under a long/slow charge. These lead crystals form outside the plates reducing capacity and may penetrate the plate separators causing micro shorts. A 6-10 amp charger is appropriate for most car batteries. Larger batteries need a higher charge rate.Trojan states "...a charger with an output current rating between 10 and 13% of the battery's rated 20-hour capacity will suffice."

If you want to read about lead acid batteries until your vision goes fuzzy try this excellent Bureau of Reclamation publication.
http://www.usbr.gov/power/data/fist/fist3_6/3-6.PDF