[RS3100]

My car strangely came up with the "Low Battery" warning the other day, less than an hour after I'd collected it from the dealer after it's 4-years-old annual service last week.
I'd driven home (about 4 miles) and parked, then returned to the car soon after to program in a SatNav destination for the next day, so I didn't actually start the engine. Not sure if I turned on the ignition or just the Sensus system.
After at most 1 or 2 minutes the low battery warning appeared and said the navigation system would turn off. Normally it would run for 15 or 20 minutes in such conditions.

I started the engine then and finished the task, the car wasn't driven at all until the next day. Subsequently I've not seen the message at all. Makes me wonder what the dealer did and whether sitting overnight reset the battery management?

The dealer connects the car to a power support supply during servicing, whilst it is connected to VIDA. Instructions in VIDA are explicit about the support supply not being connected directly to the car battery negative terminal as and for the reasons previously mentioned in this thread.

Nevertheless, that didn't prevent the Volvo tech who carried out my last dealer service ignoring the instruction as was apparent from my dashcam recording. It wouldn't surprise me if yours was the same.

But as VIDA also explains, the BMS system will resynch after 6-8 hours as long as the car is left parked with ignition key removed and all doors locked throughout that time.

If you have start/stop, the car maintains the battery at around 80% state of charge, so if you switch on systems such as the radio/nav unit without starting the engine you are already starting from a partially depleted battery state, and depending on the entertainment system installed it can be quite power hungry. If you have the ignition on as well, with sound on, DRLs and/or light switch on auto etc, you are looking at a current draw of 10 Amps or more.

If I plug my car into a diagnostic reader, which requires the ignition to be on, and don't connect it to a support power supply, I can also get a low battery warning very quickly. Note though that the warning probably relates to the sensed real time battery voltage, which will be lower with the ignition on or the radio/nav or other consumers running giving a false reading due to the power draw. The voltage will rise when the power draw is switched off, which represents a more accurate determination of the battery condition.

 

[jactac]

Having purchased a smart charger a couple of weeks ago but then the car stopped giving the Low Battery Charge warning it has now re-appeared.
So I'm going to put the car on charge this weekend.

Couple of questions though:
1. Where is the best charging point location for the negative lead ?
2. When the "Low Battery Charging" message appears, how do we know which battery it refers to, the main starter battery or the smaller support battery ?
3. My smart charger has a couple of different modes for different types of battery, however, there is a seperate mode for "AGM" batteries, which I think the V40 uses as the support battery, which is why I ask about the "Low Battery Charge" message and knowing which of the 2 batteries the message actually applies to ?
4. If the support battery needs charging, how is it located ?

Any advice appreciated.
Thanks.

 

[snowman]

Use the bolt on the inner wing for the neg lead,AGM is Absorbent Glass Mat,which is the main battery,use that setting on the charger,the support battery is behind the nearside front bumper,look for the flap inside the front nearside wheelarch but it's a fiddle,I still think you should get the battery checked by your dealer,didn't you have it booked in then cancelled ? Mine didn't charge me to check it or for the battery to be fitted ,they will tell which battery is dud,battery life varies if it's on it's way out change it,yes you can keep charging it but one day it might just leave you stranded.

 

[jactac]

Thanks Snowman,
I thought though that main battery was the EFB type and the support battery was AMG ?
This is from the Volvo site, and is specific to the V40.
"Important
When replacing the starter battery in cars with the Start/Stop function, a battery of EFB type or stronger must be installed.
When replacing the support battery, a battery of AGM type must be fitted."

Battery - Start/Stop | Battery | Maintenance and service | V40 2018 | Volvo Support

Cars with Start/Stop function, in addition to the starter battery, are equipped with a support battery.

www.volvocars.com

Your right, it was booked in but the "Low Battery" message disappeared and the Stop/Start function has worked ok since taking the car for a long run, but over the last week or so I've just been doing my usual short journeys and now the message appeared again yesterday.

 

[jactac]

I think the AGM type battery is used as the main & support battery on cars with automatic gearbox.
Manual cars use EFB as a main battery and AMG as the support battery.

This was also on the Volvo site :
"Important
When replacing the starter battery, in cars with Start/Stop function, a battery of the correct type must be fitted, EFB in cars with manual gearbox and AGM in cars with automatic gearbox.
When replacing the support battery, a battery of AGM type must be fitted".

Battery - Start/Stop | Battery | Maintenance and service | V40 2015 Early | Volvo Support

Cars with Start/Stop function, in addition to the starter battery, are equipped with a support battery.

www.volvocars.com

 

[jactac]

Just took all the covers off the battery to check what type it is, it's the EFB but it does say on the label that it if replacing, replace with the same or the AMG type..

 

[snowman]

Can not see mine but pretty sure it's AGM,I use the AGM setting on the charger on the old battery,had mine replaced with Volvo £170.

 

[jactac]

Do you have an automatic ?
Reading the info that came with my charger it says that the AGM setting on the charger can cause irreversible damage to an EFB battery or any other type of battery, hence me wanting to find out exactly what type is on the car.
Apparently fast charging is also not good for either type .

 

[snowman]

Mine is manual.

 

[snowman]

My instructions show the car setting for set Ca/Ca,MF,GEL,and many AGM battery,the AGM setting most AGM battery,the difference seems to be 14.4 V/5A and 14.7/5A.

 

[jactac]

I think chargers in AGM mode put out a bit more current because AGM batteries require a higher than normal charging current.
Reading the manual on my charger it says :
"12v mode 14.5V | 10A | Up To 230AH Batteries"
"AGM 12v mode 14.8V | 10A | Up To 230AH Batteries, For charging 12-volt advanced AGM batteries, which requires a higher than normal charging voltage"
"AGM 6v mode 7.4V | 10A | Up To 230AH Batteries, For charging 6-volt advanced AGM batteries, which requires a higher than normal charging voltage"

Then there's a mode for Lithium batteries !!
All a bit over my head if I'm honest.

Maybe when your battery was replaced it was was replaced with the AGM type, which is what is written on the EFB Volvo battery in my V40, "Only replace with the same type or AMG type battery"

 

[PAULTDI67]

Hi peeps so with all this talk about different battery types when it comes to change the battery is it just a straight swap (as in the days before everything was computer controlled ?) Is disconnecting going to upset anything ?what about radio does it need a code or is it ok while in the car ?

 

[snowman]

I am not totally sure,I know the battery monitor system which regulates both battery has to be reset,reading on here I believe you can do it yourself,when mine was on it's way out I called into my Volvo dealers and they checked it and fitted it for free,as they were competitive in price I just let them do it,no messing then.

 

[Yorkshirediscount]

Having read this entire thread I understand a lot more about V40 batteries, and I guess that with mine being a late 15 early 16 petrol manual, it must be an EFB battery. What I don't know is which charger to buy. I don't want to use an AGM charger on an EFB battery because I read that can knacker it, but chargers labelled specifically as 'EFB chargers' seem to be as rare as hens' teeth.

 

[RS3100]

Enhanced flooded batteries are normal sealed lead acid type batteries with a modified design allowing them to accept regular deep discharges with a greater life cycle than a "conventional" battery. Any normal "smart" battery charger will be fine. I use a Ctek MXS 5.0 for regular maintenance charging and being left connected for a month or so at a time when i am away and ther car is sat in the garage.

 

[snowman]

Ctek for me as well,gets more use on motorbike than the car but you just set it for battery type and vehicle.

 

[Yorkshirediscount]

Enhanced flooded batteries are normal sealed lead acid type batteries with a modified design allowing them to accept regular deep discharges with a greater life cycle than a "conventional" battery. Any normal "smart" battery charger will be fine. I use a Ctek MXS 5.0 for regular maintenance charging and being left connected for a month or so at a time when i am away and ther car is sat in the garage.

Ctek for me as well,gets more use on motorbike than the car but you just set it for battery type and vehicle.

Nice one thanks, CTEK MXS 5.0 is only £60 on evil Amazon at the moment. Nowhere else seems to come close to that price, so I ordered it.

 

[snowman]

Have one in on mother-in-law car as well,it sits in garage for weeks at a time, on hers and my motorcycle I have leads permanently attached to battery,just plug lead in,for my car I use the crocodile clips,just put the negative one on the earth stud on top of inside wing,not recommended to attach straight to battery neg terminal,apparently can upset the electronics,got new battery on my car now,in the old battery it would take day and half of so too bring it back up .

 

[jactac]

If I'm honest I'm still a bit in the dark as to what type of battery is on my V40.
Volvo Uk got back to me and said its the AGM type but my dealerships service dept said its the EFB type !!!!!
I can just about see the letters AGM on a small sticker hidden under the cables on top of the battery, but I'm not sure if it says something like "Only upgrade to an AGM type" or "Only replace with an AGM type" ?
I don't want to disconnect all the cables in case something goes wrong.
Its due for a service mid January so I'll try to find out more at that time.

 

[snowman]

Ask the dealer's when you're there ,price wise there was only about £10 or so difference when I got mine and let them do it,it's less hassle and you know it's the right one.