I have a 2016 Smax 2l diesel (48,000miles) which I've had since 2017. No issues with it until yesterday, when it wouldn't start. It had just been driven for 5 miles so engine was warm. It turned over for about 10s then stopped and I repeated this several times but it would not start. I did try pressing the accelerator but that made no difference. I then opened the bonnet to have a look at the battery terminals and they seemed ok. Then closed the bonnet and it just started straightaway. When I got home after turning it off, it started first time without a problem.

As the car is 6 1/2 years old, stop start has stopped working and I've had the "system shutting down to save the battery" message a few times last year,  I've ordered a new battery. However, I'm not entirely convinced it was caused by a battery issue and therefore would anyone have any suggestions as what else it might be? My past experience with old batteries that the more you try starting a car with a bad battery the less likely it is going to start. Also, is it normal for the car to stop trying to start on its own accord after around 10s of cranking? I did wonder about the fuel filter, but that was changed about 2 years ago.

Changing the battery looks not as straightforward as in previous cars, especially as it looks like you have to disconnect the positive terminal first to move the battery to get access to the negative terminal. I think I'll wrap electrical insulation tape around the spanner just to be safe!

Thanks for any replies.

 

 

24 minutes ago, overland16 said:

Changing the battery looks not as straightforward as in previous cars, especially as it looks like you have to disconnect the positive terminal first to move the battery to get access to the negative terminal. I think I'll wrap electrical insulation tape around the spanner just to be safe!

On a 2016 vehicle the battery is intended to be charged while still connected to the vehicle. The battery charger positive lead should be connected directly to the battery +ve terminal, and the negative lead from the charger should be connected directly to the main chassis earth point - DO NOT connect it to the battery negative terminal.

Your vehicle is fitted with a Battery Monitor System (BMS) and it is important that the negative battery charger lead is connected to the chassis, that way the BMS can monitor the charging current going back in to the battery.

If and only if, you replace your battery with a new one, then fully charge it for 12 hours before fitting it. Then once fitted you need to carry out the BMS reset procedure so that the time in service counter is reset and that the state of charge is also reset. 

 

PS. you need to update your profile.

26 minutes ago, overland16 said:

Also, is it normal for the car to stop trying to start on its own accord after around 10s of cranking?

Yes, that is normal. It stops the starter motor from overheating

2 minutes ago, unofix said:

On a 2016 vehicle the battery is intended to be charged while still connected to the vehicle. The battery charger positive lead should be connected directly to the battery terminal, and the negative lead from the charger should be connected directly to the main chassis earth point - DO NOT connect it to the battery negative terminal.

Your vehicle is fitted with a Battery Monitor System (BMS) and it is important that the negative battery charger lead is connected to the chassis, that way the BMS can monitor the charging current going back in to the battery.

If and only if, you replace your battery with a new one, then fully charge it for 12 hours before fitting it. Then once fitted you need to carry out the BMS reset procedure so that the time in service counter is reset and that the state of charge is also reset. 

Thanks for your response.  I've had a look in the manual and there is no mention of having to reset the BMS when changing the battery so is resetting it something I can do, or do you need specialist equipment?

One of the these two methods should work on your car.

On 1/19/2022 at 4:02 PM, unofix said:

Hi Ian,

Once your battery has had a good charge (better if you can leave it over night) then reset the BMS as per this video. Follow the directions carefully and the battery light will flash to confirm reset, it can take up to 8 seconds. Also it seems on some models it is very important that you sit in the drivers seat with the door closed, not sure why.

 

 

On 1/19/2022 at 4:05 PM, unofix said:

If the above reset does not work for your model then this one should work:

 

 

If your Battery was on its last legs engine would not have cranked over for several 10 second bursts without noticeably slowing down. 

1 hour ago, Tizer said:

If your Battery was on its last legs engine would not have cranked over for several 10 second bursts without noticeably slowing down. 

I'm sure your right. I think I'm just looking for the easy option and perhaps I just need to drive it and see if it was a one of.

The battery might need changing anyway as stop/start doesn't work and the system shutting down low battery warning. I appreciate that it depends on usage, but 6 1/2 years for a battery seems pretty good (it's an AGM)?

52 minutes ago, overland16 said:

as stop/start doesn't work

The very mention of S/S can lead to 6 points on your licence and a 3 months ban from the forum 🤣🤣

Of course it doesn't work, it's like the great VW scandal. It was only invented to cheat the emissions test while they got type approval. When it occasionally works that's just an accident 😉 

My last Fiesta which I bought new just over two ago the S/S worked perfectly. My new Fiesta, just over two months old now has also worked perfectly in fact in freezing weather I drive 300 yards to the end of my road and it starts working. You might think I would be over the moon with this but I actually hate it. I am now getting into the habit of starting the car and immediately pressing the S/S button to cancel it.

29 minutes ago, jsk said:

I am now getting into the habit of starting the car and immediately pressing the S/S button to cancel it.

I have mine automatically permanently disabled. It's one of the best little bits of kit I've ever bought.

I have wondered about the usefulness of stop/start as an idling engine seems to use very little fuel and surely continually starting the engine increases wear and tear.