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 (https://www.johncraddockltd.co.uk/da1409-ctek-comfort-connector-7-pin-charging-adaptor.html) 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 https://www.aulro.com/afvb/the-verandah/246755-line-auto-electrical-info.html#post3001608

[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.

[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.

Just the aux battery. The other is a standard AGM cranking battery. Tim has given some good advice, so hopefully will have it sorted shortly.

[Hawc]

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.

Tim, thanks for this and all of your other excellent advice.

[drivesafe]

Hi Alan and not sure if you understand why you need to make the earth connection away from the battery.

In certain situations, if a battery is worked hard, it can be caused to gas. An example of such a situation is if you have been cranking your motor for a fair while but not succeeding to start it.

This type of use can produce hydrogen gas in the battery and it will expel from the battery over a period of time.

When connecting leads to a battery, such as jumper leads, the last lead connected completes the circuit and this final connection can cause a spark

By making the last connection the one to the negative side of the battery, because the battery's negative is earthed to the body/chassis, you can actually make the last connection somewhere other than the battery's terminal.

This moves the spark potential away for the POSSIBLY gassing battery, and thus demonically reduces the potential of an explosion happening.

If you use the plug with the two eye terminals and connect it to the battery without having the charger connected, then you are safe, because the plug moves the spark potential away from the actual battery.


These vehicles keep a chronological map of battery events, and while you may charge the battery separately from the alternator, the vehicles memory "remembers" that the last time it checked the battery it was low, and as you have not driven the vehicle since the last battery check, it must still be low.

By you leaving your battery disconnected for a few hours or what ever, achieves the same thing as the Hard Reset does.

The reason for the hard reset is that many of the electronic devices in your vehicle, that collect and manipulate data, use two basic types of memory to store that data.

One is non-volatile memory, where the data is maintained when the power is removed.

The other is volatile ( or RAM ) memory, where the data is lost if power is removed, and this is what we are trying to delete when we do a hard reset.

Data for your Trip meter and some radio channel info and some of the chronologic battery data is stored in Volatile memory.

But unfortunately it is not just a simple case of disconnecting one of the battery terminals and then reconnecting it to clear/delete this volatile memory.

All your electronic devices have large suppression capacitors in the power supply circuits.

These large suppression capacitors are there to FLATTEN OUT any voltage spike that may occur.

But when power is removed, the same suppression capacitors now act like small batteries, and keep many of the circuits powered up, circuits like those containing the Volatile memory chips.

The suppression capacitors will progressively self-discharge over time, or by removing the cranking battery terminal clamps and bridging them together, you literally short circuit the suppression capacitors. Thus deleting any volatile memory.

Or as you did, by leave the battery disconnected for an hour or so, you allowed the suppression capacitors to self-discharge, achieving the same results.

PS, sorry Alan I was typing at the same time you were.

[DiscoJeffster]

I have personal experience of detonating a car battery as a kid - a deafening experience to say the least. I don’t recommend you do it [emoji23]

It blew into tiny fragments, the explosion deafened me for over 5 minutes, covered me in battery acid ams ruined my clothes lol. I guess it’s fair to say I was lucky that no shrapnel killed me.

I learnt a lesson that day about gassing batteries.

We we kids and enjoyed putting hacksaw blades across the terminals and making them glow red. We did this until the battery was flat. We then put it on charge and the following morning had another go. Boom!!!!!!
Battery acid also all over my friend’s fathers new Nissan Maxima! Thankfully a swift wash down prevented damage.

[StewG]

What doesn't kill you makes you wiser - In my younger days I recall soldering with a gas torch a leak in an empty petrol tank. Like Disco Jeffster I was deafened for some time afterward, but no other damage except that the tank was rather barrel-shaped and unusable rather than flat.

With the current isolation,my D4 has been idle for 3 months and because it is fitted with a Traxide DBS I have been charging both batteries through the 12V Accessory socket in the rear with either a simple battery charger (ancient but half-smart) or an 18W solar panel (with controller) when the sun shines. Both methods seem to work ok and keep the batteries topped up although the solar is not overly effective - as one might expect. I may have to do the hard reset as suggested above when I finally drive again.