Is broke or do I not know how to use it?I picked up a Schumacher SE1052 on Craigslist yesterday. On the 10 amp setting, on a mostly full 12 volt gel battery (yes really gel, not AGM) it starts at 14.2 volts, and rises steadily, reaching 15.3v after 5 or 10 minutes, at which point I unplugged it.On the 2 amp setting, different battery, also 12-volt gel, it starts at 13.38 and rises more slowly. Now, after 10 minutes is about 13.5.I'm used to smart chargers. Is this how manual chargers work, or is it defective?Thanks!

Do not use that charger on an AGM or gel. You will destroy them quickly.It sounds like it is working properly, but it is not an appropriate charger for anything but a conventional flooded cell, and even then you need to understand the charging process to know when to shut it down.

Yes the 2 amps will raise the voltage much more slowly than the 10 amps will.Plus the last bit of rising voltage will rise fast on any battery that is nearly full.BTW- AFAIK, Gel batteries are fussy about voltage and should be charged at 14.1v ISTR (or whatever the spec says for yours). The story is if you go over that voltage it will wreck the gel battery, which is why they say not to use them in RVs where their converters normally do higher voltages

Well, I hope I did not ruin the one battery. I really shouldn't do these things when I'm tired. I got these gel batteries used 10 years ago, though so it will not be a shock if something happens to them.

Naio wrote:Well, I hope I did not ruin the one battery. I really shouldn't do these things when I'm tired. I got these gel batteries used 10 years ago, though so it will not be a shock if something happens to them.What voltages have you been using on them up till now? Can you read the brand and model on them so we can look up their charging specs?

BFL13 wrote:What voltages have you been using on them up till now? Can you read the brand and model on them so we can look up their charging specs?Oh, thanks, but I know their charging specs. I wasn't using the charger to actually charge them; I was using the battery to test the charger. And yes, they do prefer below 14.1.

Manual charger question | Good Sam Community

11 Replies

landyacht318
Explorer
Mar 25, 2018

That manual schumacher will likely go upto 17 volts if left on long enough on the 10 amp setting.

Set meanwell to 14.1, spin timer to 6 hours. Perhaps give itor another hour, watching for amp to taper, or nearly stop tapering.

My neighbor has a manual 2 10 amp Schumacher in that style. Could only do 6 amps.

I have one10/2 manual in storage, but not in use since 2004, back before I had an ammeter.
Naio
Explorer II
Mar 25, 2018
I have memory problems. For regular use, I use chargers that shut off automatically.

I just have the meanwell for conditioning and special projects. I can't trust myself using the meanwell on a daily basis.
Almot
Explorer III
Mar 25, 2018
You could keep on using Meanwell. Set it to 14.1 and don't touch that tiny pot.

I attached to it a pair of old crocodile cables from (defunct) charger. And a cord with plug from the same charger. Secured cables to the slotted case with those tiny plastic-covered wire tie-downs that you get on coiled cables with new appliances etc.

Added a 4-digit voltmeter, $2 - can't trust it much, just to make sure that I didn't move the pot incidentally. Those cheap meters are hit or miss, this one was a "hit", another one a year ago at 3 times the cost was a "miss".
Lwiddis
Explorer II
Mar 24, 2018
In today’s world a manual charger? Why? And on expensive gel batteries? Oh my.
Naio
Explorer II
Mar 24, 2018
I do have a meanwell. Sometimes I just want something to top off a battery that I don't have to futz with.

I agree that the schumachers are pretty crappy. My last one, also a garage sale find, didn't last long.

I was probably dumb to buy it. I got a good deal on some other electrical stuff from the guy, and he had this charger, so I just threw it in.
Almot
Explorer III
Mar 24, 2018
In the rig she has those surplus UPS AGM kind, as I recall.

Schumacher appears to be a Walmart-level product these days. I couldn't trust them. Bought a manual 14A Meanwell regulated power supply, very accurate. You set it to 14.x and it won't go any higher. The only inconvenience is that to adjust the voltage, say, from 14.x to 13.x, you need to carefully operate with small screwdriver.
Naio
Explorer II
Mar 24, 2018
BFL13 wrote:

What voltages have you been using on them up till now? Can you read the brand and model on them so we can look up their charging specs?

Oh, thanks, but I know their charging specs. I wasn't using the charger to actually charge them; I was using the battery to test the charger. And yes, they do prefer below 14.1.
BFL13
Explorer II
Mar 24, 2018
Naio wrote:
Well, I hope I did not ruin the one battery. I really shouldn't do these things when I'm tired.

I got these gel batteries used 10 years ago, though so it will not be a shock if something happens to them.

What voltages have you been using on them up till now? Can you read the brand and model on them so we can look up their charging specs?
Naio
Explorer II
Mar 24, 2018
Well, I hope I did not ruin the one battery. I really shouldn't do these things when I'm tired.

I got these gel batteries used 10 years ago, though so it will not be a shock if something happens to them.
BFL13
Explorer II
Mar 24, 2018
Yes the 2 amps will raise the voltage much more slowly than the 10 amps will.

Plus the last bit of rising voltage will rise fast on any battery that is nearly full.

BTW- AFAIK, Gel batteries are fussy about voltage and should be charged at 14.1v ISTR (or whatever the spec says for yours). The story is if you go over that voltage it will wreck the gel battery, which is why they say not to use them in RVs where their converters normally do higher voltages