CTEK MUS 4.3 Won't Go Past 3 Bars

[Gebo]

Trying to charge a battery and the CTEK won't go past 3 bars and it hot as fire. I hooked it to another battery and it works fine.
What could be the deal? The battery I was trying to charge with it checks out fine with my battery tester (12.75 volts 565 CCA) but it was completely
dead on Friday.

 

[CharlieBauer]

How long was your completely dead battery at stage 3?

Stage 3 can last up to 20 hours on the CTEK 4.3 to bulk charge to 80%-90%. Max size battery for it is 105AH.

Your 565 CCA battery I would guess is 50AH-60AH, so it should be at least 10 hours on stage 3 from completely dead.

 

[Escape08]

Are you referring to CTEK MXS 5 with 4.3 amp? I would suggest going to any parts store and have the battery charged (FREE of charge) and then use your CTEK to maintain.

 

[Gebo]

How long was your completely dead battery at stage 3?

Stage 3 can last up to 20 hours on the CTEK 4.3 to bulk charge to 80%-90%. Max size battery for it is 105AH.

Your 565 CCA battery I would guess is 50AH-60AH, so it should be at least 10 hours on stage 3 from completely dead.

It happened while my wife was at work. It was at 5 volts at 6 pm. I’ve never experienced the CTEK taking so long and getting so hot. It’s a 575 CCA rated battery. It got to 12.5 and 565 in 4 hours.

 

[Gebo]

Are you referring to CTEK MXS 5 with 4.3 amp? I would suggest going to any parts store and have the battery charged (FREE of charge) and then use your CTEK to maintain.

MUS 4.3

 

[mk378]

If a battery is pulling a prolonged heavy charge current at 12.5 volts, it probably has an internal short.

After some charging, the resting (an hour or so open circuit) voltage should be above 12.

 

[Pelican]

Trying to charge a battery and the CTEK won't go past 3 bars and it hot as fire. I hooked it to another battery and it works fine.
What could be the deal? The battery I was trying to charge with it checks out fine with my battery tester (12.75 volts 565 CCA) but it was completely
dead on Friday.

If it worked on another battery and not on this one this battery is toast!
C-TEK is a very sophisticated piece and though the battery MAY take a charge with another charger, it may have failed elsewhere
in the checking procedure, maybe the desulfation is beyond repair or something else, but IMO the fault lays with the battery.

 

[repairman54]

Little Ctek is running wide open, that's why it's hot. Battery needs a higher amperage charge first to get it up to the low amperage charging level. Ctek is a maintainer, a small charger for Maintenace not recovery.

 

[Gebo]

Help me understand. If the battery is showing 12.6 volts after being on the CTEK, isn’t it charged?

I now have it on a charger at 10 amps. Been going about 1 1/2 hours so far. How much longer should I leave it on?

Also, assuming the battery is bad. If I take it back to the dealer won’t he see 12.6 volts and 565 CCA and tell me the battery is fine?

I have a battery tester. That’s how I know the CCA’s. FYI

It was purchased 7/21.

 

[Duffyjr]

I have the 4.3 (older version) and putting it on a good battery just for maintenance it takes about 15 hours to get to step 7. I have never paid close enough attention to say how long it sits at any given stage but it's either stage 3 or 4 that it sits at the most, I want to say stage 4.

OP I would let it sit for a few days and check it again, if's it bad your tester will show it being bad. Also if it's at 12.6 that's about all you can ask out of a battery older than a year.

 

[Gebo]

Could your 4.3 fry an egg? Lol

Mine will burn your hand. It only gets warm normally.

 

[repairman54]

Most maintainers will take charge up to 14v then throttle back to around 13.2 to maintain. That's how my BatteryMinders operate. I've got 2 on maintenance in the garage than that's the voltage reading on them now, 13.2v in maintain mode.
After being on the 10A charger for a while see how it behaves on the maintainer. If still not right make sure to knock off the surface charge on it before taking it back. Load test is the sure test.

 

[Gebo]

Load test has to be done with special equipment that only a dealership or auto parts store has.

In other words, that’s the true battery checker test?

 

[Gebo]

Most maintainers will take charge up to 14v then throttle back to around 13.2 to maintain. That's how my BatteryMinders operate. I've got 2 on maintenance in the garage than that's the voltage reading on them now, 13.2v in maintain mode.
After being on the 10A charger for a while see how it behaves on the maintainer. If still not right make sure to knock off the surface charge on it before taking it back. Load test is the sure test.

How do I knock off the surface charge?

 

[Duffyjr]

How do I knock off the surface charge?

If it's still in the vehicle turn the headlight on for a few minutes.

 

[mk378]

Load test has to be done with special equipment

The load tester is just a big resistor to see how much the voltage drops under a load simulating an engine starter. It is not expensive at all, any place that sells batteries should have one that they use on warranties or other times there is a question whether a battery is bad.

100 Amp, 6/12V Battery Load Tester

Amazing deals on this 100 Amp 6/12V Battery Load Tester at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Load tests are only valid with the battery charged well. The first load test after charging should be disregarded since it is mostly "surface charge" as noted.

Just to be clear, when you say you measure 12.5 volts, this is with nothing (other than the voltmeter) connected to the battery?

 

[CharlieBauer]

Also, assuming the battery is bad. If I take it back to the dealer won’t he see 12.6 volts and 565 CCA and tell me the battery is fine?

Some testers are more sophisticated than others.

I took a battery that was starting fine to Autozone and O'Reilly before warranty was up. AutoZone tester said bad cell. O'Reilly said battery was fine. A few months later, battery failed with a bad cell.

 

[Gebo]

The load tester is just a big resistor to see how much the voltage drops under a load simulating an engine starter. It is not expensive at all, any place that sells batteries should have one that they use on warranties or other times there is a question whether a battery is bad.

100 Amp, 6/12V Battery Load Tester

Amazing deals on this 100 Amp 6/12V Battery Load Tester at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Load tests are only valid with the battery charged well. The first load test after charging should be disregarded since it is mostly "surface charge" as noted.

Just to be clear, when you say you measure 12.5 volts, this is with nothing (other than the voltmeter) connected to the battery?

It’s with a Solar BA9. That gave me the CCA’s as well.

 

[BMWTurboDzl]

Little Ctek is running wide open, that's why it's hot. Battery needs a higher amperage charge first to get it up to the low amperage charging level. Ctek is a maintainer, a small charger for Maintenace not recovery.

CTEK Multi US 7002 has a reconditioning feature but even then it must be fully charged to first.

 

[Gebo]

Update

I left it on 10 amp charger for a few hours. Took it off and put it back on CTEK and it went to 4 bars quickly. Even though battery showed over 12.5 volts it wasn’t charged enough. This morning the CTEK had gone to green light and I did a load test with the tester mk378 suggested. Battery tested fine. Thanks for your help. Now I have a load tester.