se-1010 battery charger goes greater than 15 volts

[1 FMF]

have an old schumacher se-1010 battery charger.
It is not the se-1010-2 that you fill find googling, in fact I cannot find a web image of what i have which is "SE-1010".
Problem I have is on a regular lead-acid car battery the charger will run up to 15.0 volts and higher. Was wondering if anybody might know what might be wrong with it.
It's just a metal box, has am amp meter on the front that reads 0-5-10-15 amps, an on/off switch, and a 6v/12v switch.
I had a deep cycle trailer battery that was severely discharged down to ~10.5 volts so i used this charger on it. It ran at around 8 amps for a few hours and brought battery voltage up into the 13 range. I checked back later and battery voltage was at 15.0-15.1 volts. I had a second battery nearby that was good and near full charge (12.55 volts) so I tried the charger on that and within 3 minutes the voltage was at 15 and the ammeter was showing around 4 amps.

 

[Dave Sherman]

Sounds like it's just an old-fashioned, unregulated charger, which I wouldn't be surprised if it drives the voltage to 15 volts or more. You can't leave one of those unattended for very long. I have one that will get the battery bubbling and drive it to 14.8 volts or more while still pumping 4-5 amps, but it's only about 10 years old.

Perfectly normal, get a smart charger if you want one that can be left unattended.

 

[JHZR2]

Totally fine. I was seeing this on my schumacher charger that is just a couple years old (digital one). I was up at 15.6V with the ambient temperature at around 40F.

Charging schemes are usually a bulk charge (constant current, variable voltage), then an absorption charge (constant voltage of 14.9 or so, temperature dependent, with current dropping for that voltage until 0.05A or so), then a float stage (13.6V or so, chemistry and temp dependent).

Four-stage chargers perform an equalization charge that takes the battery up to 15.6V or so, more or less, temperature dependent. It is usually timed and controlled, just to perform a final topping, in a means that is kind of a hybrid of the two previous charge schemes.

So Ill bet you are seeing the equalization mode, which Im sure the Schumacher has built into it based upon the voltages we are seeing (especially since I know that mine drops to around 13.6V after a time).

No big deal. In some circumstances you may even hear a slight boiling of electrolyte. So long as the case is not bulging, you do not see/hear release of gas, excessive voltage, formation of crystals or signs of acid/liquid on the outside, etc., youre OK. Especially in these temperatures...

 

[JHZR2]

Originally Posted By: Dave Sherman

Perfectly normal, get a smart charger if you want one that can be left unattended.


Smart chargers will go that high too if they have a four-mode setup. The difference is that power electronics based units can current limit faster/smarter while doing this.

 

[mechtech2]

A little high, but this used to be common with old chargers.

JHZR2 seems to know chargers very well!

 

[Dave Sherman]

Originally Posted By: JHZR2
Totally fine. I was seeing this on my schumacher charger that is just a couple years old (digital one). I was up at 15.6V with the ambient temperature at around 40F.

Charging schemes are usually a bulk charge (constant current, variable voltage), then an absorption charge (constant voltage of 14.9 or so, temperature dependent, with current dropping for that voltage until 0.05A or so), then a float stage (13.6V or so, chemistry and temp dependent).

Four-stage chargers perform an equalization charge that takes the battery up to 15.6V or so, more or less, temperature dependent. It is usually timed and controlled, just to perform a final topping, in a means that is kind of a hybrid of the two previous charge schemes.

So Ill bet you are seeing the equalization mode, which Im sure the Schumacher has built into it based upon the voltages we are seeing (especially since I know that mine drops to around 13.6V after a time).

No big deal. In some circumstances you may even hear a slight boiling of electrolyte. So long as the case is not bulging, you do not see/hear release of gas, excessive voltage, formation of crystals or signs of acid/liquid on the outside, etc., youre OK. Especially in these temperatures...


That may be, but don't the smart chargers usually have some indication of what they are doing? The last Schumacher smart charger I had didn't have an ammeter, but it had some indicator lights and a digital voltmeter telling me what it was doing. Just assuming the OP has a smart charger may not be such a great idea, as I also have a dumb battery charger that fits the OP's description: Ammeter and a 6 volt/12 volt switch. It won't take long to boil a battery dry at 15 volts and 4 amps.

 

[1 FMF]

this is not a smart charger, it's an old one. It's a "SE-1010" which does not even show up on any website.
I understand the 4 stages of charging, my understanding is with the bulk (first) stage you can really pump current into the battery if it's low and get it up to around 80% state of charge fairly rapidly. After that, getting the SOC to 100% takes a while because you have to reduce current so you don't cook the battery. With this old charger, it seems like it's only good to use on weak batteries and if I use it I have to watch it and turn it off shortly after voltage is over ~14.5 volts.
I know it's a problem because I cooked two batteries with it a few years ago.

 

[Warstud]

Originally Posted By: JHZR2
Originally Posted By: Dave Sherman

Perfectly normal, get a smart charger if you want one that can be left unattended.


Smart chargers will go that high too if they have a four-mode setup. The difference is that power electronics based units can current limit faster/smarter while doing this.


Had a smart charger charge mine up to 18V before. Called Schumaker and they said it wasn't a problem.

 

[JHZR2]

Originally Posted By: Dave Sherman


That may be, but don't the smart chargers usually have some indication of what they are doing? The last Schumacher smart charger I had didn't have an ammeter, but it had some indicator lights and a digital voltmeter telling me what it was doing. Just assuming the OP has a smart charger may not be such a great idea, as I also have a dumb battery charger that fits the OP's description: Ammeter and a 6 volt/12 volt switch. It won't take long to boil a battery dry at 15 volts and 4 amps.


15.6 VDC, especially at CT temperatures is not an issue.

Want to learn more in a short time, see this:

http://nyelectrathon.com/index.php?option=com_phocadownload&view=category&download=26:battery-charging-basics&id=12:batteries&Itemid=56

 

[JHZR2]

Originally Posted By: 1 FMF
this is not a smart charger, it's an old one. It's a "SE-1010" which does not even show up on any website.
I understand the 4 stages of charging, my understanding is with the bulk (first) stage you can really pump current into the battery if it's low and get it up to around 80% state of charge fairly rapidly. After that, getting the SOC to 100% takes a while because you have to reduce current so you don't cook the battery. With this old charger, it seems like it's only good to use on weak batteries and if I use it I have to watch it and turn it off shortly after voltage is over ~14.5 volts.
I know it's a problem because I cooked two batteries with it a few years ago.


But remember, if youre operating out in the cold in CT, there is a temperature adjustment that makes 14.8V-15V the correct voltage even for bulk charge.

If the thing is cooking batteries, go to a box store and buy the schumacher land and sea smart charger, or a batteryminder 12248 from online.