Submariner1
Senior Member
- Joined
- Sep 3, 2016
- Messages
- 4,694
- Reaction score
- 788
- Location
- Windsor Berkshire
- Your Mercedes
- CL500 2009 5.5
I had Mobilo around today (circa 3 hours) re my Duff replacement battery???
Firstly, since the RAC takeover Mobilo no longer do Warranty repairs, it has to go to a Main Dealer.
Bad for me that means a STAR check and a battery check if it fails its free if it passes I pay!
Take the first defective battery that would have cost me > £500 if it hadnt failed on the fourth battery test! So very bad news if you have an intermittent fault. ££££
Of course she started perfectly ... as they do with intermittent faults , no dash messages.
When he arrived it was showing 12.2V ... enough to start a car.
The first STAR test pulled up 10 “ stored” fault codes, none current. Thankfully none on the EPB or ESP Controller.
After running for 15 mins, she was at 12.7V and the second STAR test passed with flying colours Zero Fault codes!!
Alternator passed as did battery control modules.
As for the drain .... hmmm as the battery was pretty well flat (not Ctek top up charged for 6 days and only a few small trips) the first shutdown took 6 mins. The second shutdown took 6 mins both ending in 0.00A drain. During most of the shutdown the drain was 0.5A.
However the 3rd took 10 mins 40 secs to reach 0.00 A. During this period it was frequently at 0.8 Amps.
He then said he would have expected it to shutdown to zero amps , pretty much instantly.
That surprised me ... as I was led to believe. They could all take anything from 5 mins to 20 mins to shutdown.
His conclusion
It was taking too long to shutdown, and that was draining the battery. And possibly, although no evidence it might switch on at some period and have another 6 mins or 10 mins drain.
He was unsure how to answer my question ... OK if it takes 6 mins to shut down, thats 1/10 of an hour. So At 0.5As so thats lets say a “one off” battery drain of 0.050AHs ... surely not enough to kill a battery in 3 days!
True it could, unknown to me wake up, and repeat that an unknown number of times!
But how the hell do you find that?
So my question is .. is it normal to shutdown in zero minutes or is 6 minutes more the norm?
Firstly, since the RAC takeover Mobilo no longer do Warranty repairs, it has to go to a Main Dealer.
Bad for me that means a STAR check and a battery check if it fails its free if it passes I pay!
Take the first defective battery that would have cost me > £500 if it hadnt failed on the fourth battery test! So very bad news if you have an intermittent fault. ££££
Of course she started perfectly ... as they do with intermittent faults , no dash messages.
When he arrived it was showing 12.2V ... enough to start a car.
The first STAR test pulled up 10 “ stored” fault codes, none current. Thankfully none on the EPB or ESP Controller.
After running for 15 mins, she was at 12.7V and the second STAR test passed with flying colours Zero Fault codes!!
Alternator passed as did battery control modules.
As for the drain .... hmmm as the battery was pretty well flat (not Ctek top up charged for 6 days and only a few small trips) the first shutdown took 6 mins. The second shutdown took 6 mins both ending in 0.00A drain. During most of the shutdown the drain was 0.5A.
However the 3rd took 10 mins 40 secs to reach 0.00 A. During this period it was frequently at 0.8 Amps.
He then said he would have expected it to shutdown to zero amps , pretty much instantly.
That surprised me ... as I was led to believe. They could all take anything from 5 mins to 20 mins to shutdown.
His conclusion
It was taking too long to shutdown, and that was draining the battery. And possibly, although no evidence it might switch on at some period and have another 6 mins or 10 mins drain.
He was unsure how to answer my question ... OK if it takes 6 mins to shut down, thats 1/10 of an hour. So At 0.5As so thats lets say a “one off” battery drain of 0.050AHs ... surely not enough to kill a battery in 3 days!
True it could, unknown to me wake up, and repeat that an unknown number of times!
But how the hell do you find that?
So my question is .. is it normal to shutdown in zero minutes or is 6 minutes more the norm?