Battery Charger QUESTION?

Status
Not open for further replies.
Joined
Jan 27, 2003
Messages
1,837
Location
Pac NW
The meter on my 10amp (Schumacher) charger is out: when charger's clips are connected to a 12 volt battery that's a little low, what should the voltage reading be between the two battery terminals?

I don't think I can read actual amps output with the test device I have without opening up the charger itself, but the voltage reading I'm now getting hooked up as above is about 16 volts. Needless to say I don't have the battery cables hooked up.

Does it appear I'm actually charging the battery to you guys?

Thanks in advance!
 
Normal fully charged battery is 12.6, so anything above that is charging. 16 VDC is a little on the high side, I wouldn't leave that hooked up for more than 24 hours, preferably less, check your electrolyte (water) level when you're done.
 
Thanks (again) for the most prompt replies! I'll keep a close watch, but once the battery consistantly reads 12.6 volts I'll hook up my battery cables and give it a go. Probably oldest battery I have (age unknown) and the F150 sits outside. It has been pretty cold around here all December, so a low battery is not to be really unexpected. I usually go out and start it and dive around at least once a week.

I'm almost ready to open this charger up and see if it is just a loose connection to the ampmeter internally, but as long as it is charging I'm happy. This is my spare charger (and the one @ the Beach) and I have plenty of Battery Tenders for maintenance.

Cheers!
 
fully charged battery fresh off the charger will usually read about 13.2-13.3

after sitting for half an hour usually 12.6~~

thats a regular charger not "float/tender"
 
Is the meter analog or digital? I would suspect the charger would fail before the meter if its analog unless you dropped the charger.

Leave the charger on overnight and see how it is in the morning. Voltage is not a great way to test a battery unless you wait 24 hours for the surface charge to go away and have a high quality meter.

A carbon pile load test or conductive test are better and can be done immediately after charging. The conductive can be done with a battery even if its not fully charged.

Some of the fancy Schumnacher "speed chargers" go through a couple of phases of battery charging so the voltage may change as the phases change.
 
Last edited:
I bought a Schumacher SC1200A for about $35 on Amazon. Pretty good price I thought for a micro processor controlled charger. May not be worth fixing a broken one.
 
My 6A/2A charger from walmart is a SE-82-6 re-branded to WM-82-6 and has an amp meter. It can read zero if the battery is totally dead. It normally reads in the 2-3 amp range once the battery is up in a good state of charge. If it hums when connected, its working.

A battery charger can put out 18V and boil a battery if its left on for a long time. Anything above 13V will charge the battery unless it is bad with a surface charge or sulfated.
 
My old Schumacher is an old analog 12v-6v 2/6amp and works great. The one at the Beach came from my neighbor and it has a three-way selector for "Manual", "Maintenance-Free Automatic" and "Deep Cycle": this is the one with the ampmeter question.

Thanks, again to all! & CHEERS!

p.s. The battery fully charged in about 12 hours on manual, good voltage reading the following morning. BatteryTender Jr. then ran for 10 seconds and read "green" (NOT RED, GREEN ).

Then I got serious and rebuilt/cleaned the cable attachments, including baking soda soaks and stripping away the paint (!) on the terminal attachments. Why new ones would have much of the surfaces covered with red/black enamel is way beyound me.
 
Status
Not open for further replies.
Back
Top