Is this normal behavior for a battery charger?

[bradp]

See attached.  I’m wondering about the dial excursions.  The documentation that came with the charger is nil.  I’m just using in on my wife’s old jeep battery now to see if it will still hold a charge. 

Thanks.  

Brad 

[RLCarter]

If the polarity of the leads are reversed or the battery has a short it's normal 

 

[carusoam]

See if you can find the info for that specific battery charger on line...

If it is modern with a computer chip driving the voltage,  it could be doing the voltage sweep on purpose?

See if you get the same result with the different rates of charge.

PP Thinking out loud, not a mechanic...

Best regards,

-a-

[bob865]

Looks like it is the normal cycle.  A 12V nominal car battery is 14.4V.  It looks like when it hits 13V it turns on and runs until 14.4 then turns off. 

[ArtVandelay]

That’s fine, my Harbor Freight battery charger does that too, that’s the normal if the battery is fully charged.

[bradp]

Ok thanks for the info.   I couldn’t for the life of me figure out whether this was the “automatic” feature of the charger.  I’ll try it on the 2A maintainer to see if the voltage sweep continues.   The polarity is confirmed correct on this one. 

Trying to see if I can breathe some life into my wife’s old jeep XJ which is going to be my little project car.  

[PaulM]

That is standard on that era of charger (exide etc).  It indicates that the system "thinks" it is full.   Usually you do the initial charge on the 10A setting.. and it starts the "flicker".. then you switch it down to the 2A setting... and eventually that will also "flicker".. then the battery is as full as that charger will get it.

The more modern "float" chargers will switch from charge to "maintain"  battery tender, battery minder..

for 12v batteries I usually pick up whatever Walmart schumacher 1.5A charger is in store for tending the battery over the winter.. Motos, cars, etc. 

https://www.walmart.com/ip/Schumacher-XM1-5-Maintainer-1-5-Amp/15140193

[jaylw314]

Here's the link to the Schumacher website.  The manual is on that page.

I glanced through the manual.  It looks like it has a 20A constant-current charge cycle, a 2A constant-voltage cycle, and then a trickle charge maintain cycle.  My guess is that when the charge current decreases to a certain point during the constant-voltage cycle, the charger goes to the maintain cycle to examine the battery voltage.  If it is still too low, it goes back to the constant-voltage charging.  The manual notes that during the maintain cycle, it will revert to charging if it sees a low battery voltage.

FYI, some people say that 20A is too high for an AGM battery.  Likewise, the voltage during the maintain cycle is probably for fluid electrolyte batteries, and can supposedly damage AGM batteries.  Schumacher makes other chargers that specifically have an AGM option

Edited January 17, 2018 by jaylw314

[Yetti]

just going to leave this here .   The powercart plug on my F is a

an-2552