Battery issue or CTEK charger issue?

[luthj]

I have read some white papers by universities testing rapid charging of AGM batteries for vehicle applications (back before lithium). High voltages are fine for rapid recharge cycles on batteries that are cycled very deeply. At least on quality AGMs. The issue is thermal runaway, which requires some monitoring, but is still fairly rare.

Now if you exceed 16V, thats a different story, the hydrogen production will overwhelm the valves and reductive catalyst, and venting will occur.

The major AGM killer is chronic undercharging, and going to float too soon. Most AGMs can't tolerate hours at 15V+ required to recover hard sulfation (like flooded batteries can). Though some brands (lifeline for example) tolerate this, and in fact should be recovery charged if partial recharge cycle abuse is occurring.

 

[Ballbearing]

The battery is sitting at 12.97 volts right now, which has been 6 hours or so since I last checked.

The CTEK never increased voltage or made it past stage one without faulting. When I bought the battery it was at 12.37 volts from the store. After several attempts with the CTEK I just reverted back to the DieHard, which apparently charged it fine.

I will try to bleed off some voltage to 12.6 as advised and then hookup the CTEK one more time. If it doesn't work then I am going to just stick with the DieHard for now. I did read a lot of positive reviews on a BatteryMinder product that looks similar to the CTEK. It, too, appears to be made to do what I am asking.

Thanks to everyone so far. Lots of good advice and knowledge, which verifies that I know even less than I initially thought about this.

 

[ConcordCarlos]

My CTEK 7002 Mulit USA just bit the dust. It won’t go beyond stage two, but it brings the battery to 13.7 volts after a few hours. It’s only 13 months old so I am working on retuning it to CTEK.

 

[67cj5]

My CTEK 7002 Mulit USA just bit the dust. It won’t go beyond stage two, but it brings the battery to 13.7 volts after a few hours. It’s only 13 months old so I am working on retuning it to CTEK.

Sorry to hear that hopefully they will help you out,

 

[Ducky's Dad]

Ctek is pretty good about supporting their stuff and replacing it if defective. About three years ago I had a 7002 connected to my Indel B to keep some antelope frozen while I was out of town. Everything was good when I left and totally defrosted when I got back. Left the Ctek in "supply" mode and it managed to turn itself off while I was gone. I was pretty pissed about losing the meat, but Ctek sent me a fresh charger.

Add: Just to clarify, the Indel was in my truck, powered off the house battery, and the Ctek was connected to the battery. Battery was newish AGM, but dead when I got home.

 

[ConcordCarlos]

Sorry to hear that hopefully they will help you out,

They sent me a replacement charger after I sent mine in for repair.

 

[Buddha.]

I have a diehard charger like that. It has a switch that selects either “conventional/deep cycle” or “sealed maintenance free”. Does that setting change the voltage it’s charging at?

 

[luthj]

Typically such a switch lowers the votlaged for sealed batteries. Always confirm it with a meter though.