[andynz22]

Have had a very intermittent fault for a year or so now. When I drive away from our driveway the car occasionally stops accelerating and wont rev above 1500rpm. Basically I can limp along at about 10km hour. In the past this cleared after stopping by the roadside then taking off again with no further problem.

2 days ago I did the same pull over to the side of the road but the fault did not clear. Regardless of how far I pressed the accelerator, the engine revved at 1500 with a cyclic variation of about 100rpm every second. I disconnected and charged the battery for day and today it started and ran fine.

In all these cases the car was started after not being used for a couple of weeks and with some short runs when it was started so the engine turn over was quite slow (low battery).

I had thought there was a sensor fault of some sort but will a slower turn over with lower battery voltage potentially cause the ECU or other control module to get "mixed up"?

 

[Moparlife]

Definitely sounds like it's going into limp mode but the question is why. If it's doing that it should be throwing a code or 2. Do the key dance and have a look at the codes. Depending on what you see will help you decide the next move

 

[protego]

It's going into limp mode due to the low battery level, might be time for a new battery. You might also notice that the A/C does not work in similar situations and sometimes it will throw the BAS/ESP fault lights.

 

[andynz22]

It's going into limp mode due to the low battery level, might be time for a new battery. You might also notice that the A/C does not work in similar situations and sometimes it will throw the BAS/ESP fault lights.

Thanks Pretego. Good to have confirmation. After the battery charge the engine turned over fine and no problem. Maybe a battery trickle charger might be a good idea when not being used for a couple of weeks.

Is it OK to use a battery trickle charger on the battery when the battery is still connected?

Cheers
Andy

 

[MADDOG]

Yes, it's OK to use the trickle charger with the battery in the car. Just make sure your charger will shut off when battery voltage reaches a certain level.

 

[andynz22]

I found a ctek 3.6 which looks like a good charger tender to leave on long term. Is it OK to connect this on the jump start terminal under the hood rather than directly to the battery terminals at the rear?

Or can you even plug it in via the all ways on cigarette lighter sockets?

 

[Jaffa]

Or can you even plug it in via the all ways on cigarette lighter sockets?

Avoid using the cigarette lighter socket for charging the battery as it has only a 10A fuse and it's wired through the main loom.
Better to use the alternatives you suggested.
Don't want to tempt fate smoking the car wiring :slap:

cheers

 

[DESIREE]

Avoid using the cigarette lighter socket for charging the battery as it has only a 10A fuse and it's wired through the main loom.
Better to use the alternatives you suggested.
Don't want to tempt fate smoking the car wiring :slap:

cheers

The OEM LIGHTER-CIGAR fuse in my 2005 300C is a 20-amp unit (fuse #18, rear fuse box). My automotive battery charger has a maximum output rating of 6 amps. So no worries.