Battery charging problems

[Hawc]

Hoping for some help with a battery charging issue. Given the pandemic, my 2014 D4 has had next to no travel, so I purchased a CTEK MXS 7.0 charger. Based on the TPMS display (plugged into accessory socket) the battery had been sitting on 12.4 or 12.5v, with 14.7v when driving. I have one of Tim’s Traxide DBS with a 55a/h yellowtop. On Saturday I charged the main battery on the CTEK’s normal setting for approx. 20 hours. According to the charger, the battery reached float. Afterwards the car, however, gave me a low battery warning with instruction to start vehicle. The voltage reading was 12.4v, i.e. the same as before. I started the car with no problems and drove for about thirty minutes. At the end of the drive, the low battery warning remained.

Having realised that I should have used the AGM mode on the charger, on Sunday I charged the main battery on AGM mode for about 20 hours with the same result. Battery reached float, volts reading as 12.4 and low battery warning remains.

I have gone through previous posts and can’t find the answer to this one, so hoping for some help please. Why after two long charges do things seem to have gone backwards? Have I stuffed the battery by using the normal mode instead of AGM in the first instance? What can I do to fix? Any advice gratefully received. Thanks in advance.

Cheers,
Hawc

[Tombie]

Where did you attach the battery charger?

Negative must go to body earth point - not the terminal.

[Hawc]

Where did you attach the battery charger?

Negative must go to body earth point - not the terminal.

It was attached to the terminal. Do you know what the implications of that are? Just didn’t charge properly or something more serious...?

[Tombie]

It was attached to the terminal. Do you know what the implications of that are? Just didn’t charge properly or something more serious...?

The BMS monitors the Negative feed, it cannot see the changes up that cable if you connect to the terminal.

Throw it back on the charger with it connected to the nearby earth point in front of the battery.

[Hawc]

Thanks. Will give that a shot tonight. Cheers.

[Max Headroom 2.3m]

It was attached to the terminal. Do you know what the implications of that are? Just didn’t charge properly or something more serious...?

I wouldn’t think so. I am not an auto-electrician but from my understanding, connecting to the negative battery terminal instead of an earth point, increases the risk of creating a spark close to a potential source of hydrogen gas and hence explosion risk – not to be taken lightly. By connecting the negative of the battery charger to a remote earth point on the vehicle moves any potential spark further away from the battery.
Charging with the normal setting (=14.4v) on the Ctek shouldn't damage the AGM battery which needs 14.7v but will under charge it. You were able to start and drive your car which suggests that the electrics weren’t damaged although can’t definitively rule out charging circuits but I can’t see why it would. If the battery has been undercharged for a while, e.g. short trips, then the recent lack of use may have just been enough to finished it off. How old is the AGM main battery?
Our first battery only lasted 18 months so now I use a Ctek Comfort Connector 7 Pin Charging Adaptor DA1409 with a Ctek charger plugged into the left (white) trailer socket and haven't had any battery issues since despite only doing about 8k kms/year. Thanks for reminding me to do mine.

Edit: Apologies, didn't see Tombie's latest post. I bow to greater knowledge.

[RANDLOVER]

Hoping for some help with a battery charging issue. Given the pandemic, my 2014 D4 has had next to no travel, so I purchased a CTEK MXS 7.0 charger. Based on the TPMS display (plugged into accessory socket) the battery had been sitting on 12.4 or 12.5v, with 14.7v when driving. I have one of Tim’s Traxide DBS with a 55a/h yellowtop……………………..

Cheers,
Hawc

Are both batteries "Yellowtops" as the back-up/house/fridge battery, may be dragging the cranking battery down before the Traxide opens the contact to disconnect it. Tim will know what the threshold voltage is for that.

[gavinwibrow]

Hoping for some help with a battery charging issue. Given the pandemic, my 2014 D4 has had next to no travel, so I purchased a CTEK MXS 7.0 charger. Based on the TPMS display (plugged into accessory socket) the battery had been sitting on 12.4 or 12.5v, with 14.7v when driving. I have one of Tim’s Traxide DBS with a 55a/h yellowtop. On Saturday I charged the main battery on the CTEK’s normal setting for approx. 20 hours. According to the charger, the battery reached float. Afterwards the car, however, gave me a low battery warning with instruction to start vehicle. The voltage reading was 12.4v, i.e. the same as before. I started the car with no problems and drove for about thirty minutes. At the end of the drive, the low battery warning remained.

Having realised that I should have used the AGM mode on the charger, on Sunday I charged the main battery on AGM mode for about 20 hours with the same result. Battery reached float, volts reading as 12.4 and low battery warning remains.

I have gone through previous posts and can’t find the answer to this one, so hoping for some help please. Why after two long charges do things seem to have gone backwards? Have I stuffed the battery by using the normal mode instead of AGM in the first instance? What can I do to fix? Any advice gratefully received. Thanks in advance.

Cheers,
Hawc

Several excellent related articles by Tim/Traxide in this thread On-Line auto electrical info

[drivesafe]

Hi Hawc, there have been quite a few similar problems reported over the years, and one fix it to do a HARD RESET.

You do this by first removing the negative cable clamp from the Optima's Negative ( - ) battery terminal.

Then remove both the negative ( - ) and positive ( + ) cable clamps from your cranking battery.

I usually let it sit like that for 20 minutes or so.

Then get a single jumper lead and connect one end the negative battery clamp ( NOT TO THE BATTERY'S NEGATIVE TERMINAL )

Then touch the other end of the jumper lead to the positive battery clamp ( AGAIN, NOT TO THE BATTERY'S POSITIVE TERMINAL )



Once this is done, refit the cranking battery's positive ( + ) clamp.

Then refit the cranking battery's negative ( - ) clamp.

And lastly refit the Optima's battery's negative ( - ) clamp.

Then try turning on your ignition and see if you are still getting the message.

[ATH]

I've recently had exactly the same prob. after charging the main battery with a C-Tek but only a 4 stage one. Low battery/start car warning message came up. Now my C-Tek came with a plug in thing (and croc clips) which I assumed connected to both battery terminals so that's what I did and never had a problem with charging.
Now everyone says this is wrong and the negative lead should go to an earth away from the battery..... anyway, to get rid of the warning message I just removed the earth lead from the battery and left it off for an hour or thereabouts and all fixed, it hasn't come back again over the last few days.
AlanH.