Charger CTEK MXS 5.0

[sk546]

Originally Posted by Mad Malc

My mistake, I meant 48 volt. Surely as explained above, the Volvo has a system that enables/converts 12 volts in to a 48 volt charging capability.

The DC-DC converter that charges the 48v battery requires the Starter/generator to be running (i.e. ICE running) and cannot take the static 12v battery voltage alone to charge the 48v system.

[Mad Malc]

This is good education, thank you. So if you have a flat battery are not able to jump start the car like you can with our S90?

[LRS]

This is how the DC-DC Converter is wired in the system. There are some really good vids online to watch.

Mild Hybrid.jpg

[sk546]

Originally Posted by LRS

This is how the DC-DC Converter is wired in the system. There are some really good vids online to watch.

Attachment 152692

Well, every days a school day.

Surly the DC-DC Converter requires the cars systems to be running (i.e. ignition on at least) to be operational as I cant see it running all the time.

[Chudy85]

Originally Posted by Hadajag

I am a bit confused by this discussion. I thought that the 48 V battery was only charged by the starter/generator is this correct
As described the 12V battery is physically small.How is this charged by the car? There does appear to be an alternator on front left of engine if so this should charge the 12V battery in only a few miles.
Any way decided to connect my CTEK charger that I have for use with my classic cars. It took 90 mins to move off 3 to 4 status lights I am going out now at 2.5 hours to see where its got to.
Edit still on 4!

When I started this thread I was referring to my car that isn't a Mild-hybrid vehicle and there isn't a 48v installation in my car. But it is nice to learn something new.

Back to my battery 12V only. My max charge was 78%. After the second charge, my battery capacity went up to 85%. Today I will connect CTEK again and I shall see if my battery capacity will be going any further or if this is the maximum for my starter battery.

I need to add that the support battery voltage was 11.20V before CTEK was connected now seats at 12.5V. ATM The s/s system is always available unfortunately 🤷😆😆 when during the last 2 years it was maybe 4 times activated.

My starter battery voltage now sits at 12.48V after all night compared to 11.9V - 12.1V before CTEK did the work.

[Chudy85]

I think is worth to share it with you.

Yesterday, my battery was charged to 94%, first time ever 😀 but I had to disconnect it as I won't leave it overnight on my driveway.

Today I had a longer run with the diagnostic tool connected and I was looking for how much changing current will be sent to the battery and if it will charge even more than was.
What I found was car won't charge the battery if the Stage of Charge is over 85%.
Only when the battery level dropped to about 84.8% car start to charge the battery then over the next hour was constantly kept at 85% flat.

Interesting fact for me but also I am wondering if there is a need to charge my starter battery over 85%.
I was looking to connect the charger tomorrow for the whole day and evening but now I don't know if there is any need for that.

What do you guys think about this?

[nu11eaf]

85% must be the optimum level setting to prolong the battery life, my phone has a setting I can turn on to limit the battery to 85% charge, the setting says
"to extend the lifespan of your battery, limit the maximum charge to 85%"

[Chudy85]

Sadly Support battery service required is back.

A few weeks ago I had information on Dash that Start/stop support battery service required I have charged both batteries through a charging point under the bonnet and all was good until today!
The support battery is dead at 10.2V only.
Even if I am driving or charging by the charger there is still only 10.2-10.5V. Even the charger won't wake up this battery.

I think only a new battery is needed.

Do you know if that will be enough just to unscrew 2 bolts and simply replace with a new one?

Will it be enough just to delete this DTC by diagnostic tool from CEM and the issue will disappear or need to drive for a longer distance?
I saw the YT video that you can disconnect 2 sockets under the bonnet and negative connector from the main battery. But it will reset the main battery too and the car will think I have replaced both of them.

Any advice?

[Chudy85]

Update to my last post.

I have an open lid where the support battery sits, and this is what I found (see attached picture).

The terminal connectors were corroded. I have checked the voltage on the lead cables. The voltage on the cables was around 10V when on the terminal itself was flat at 12.48V.

After cleaning those connectors, the voltage on a diagnostic tool straight was the same as on a multimeter. The first time after the engine started, no issues with the support battery. Short journey and straight after I moved away, my car's S/S became available.

On the diagnostic tool, you can see that the car is charging this battery.

The problem was solved within 20 minutes and cost me nothing.

It's worth checking if you have the same issue as me before you give the car to service; it could save you money.

[ACanning]

Chudy85

Thanks for the info. My car is exhibiting the same symptoms as yours in that I have the start/stop warning when I start the car. I recently gave the car an overnight charge which solved the problem for about 3 weeks but the message has now returned. I've just checked but don't have the corrosion your car did so I'm wondering now whether to take it to the Volvo dealer or attempt to change the support battery myself (assuming I can buy one). I suppose the other question is whether something else is causing the Start/Stop message?

If I attempt my own battery change is it just a matter of unplugging the old battery and replacing it with a new one or is it more involved than that?