Hi, and thanks in advance.

 

I have recently been getting low battery warnings on my 2010 Superb 1.9 TD.

 

Looking through the forum this seems to be reasonably common, but in all other cases I could find people seem to either be running a high spec car with a lot of electrical gizmos, or doing low mileage. I run the basic (S?) spec (with a sat nav. normally plugged into the 12V socket), and almost all my journeys are 20 miles plus (although thinking about it the headlights are on pretty much all the time). However The battery is probably the original, since it was unlikely to have been changed when I bought it in 2013, and I haven't changed it. The warning sounds if the car hasn't been driven for a couple of days or more- there isn't normally an issue if I have driven it the day before. The car has always started fine.

 

So as far as I can see the problem is either:

1) The battery is getting on a bit and needs changing, although my absence of lots of electricals should mean mine has an easy life.

2) The alternator isn't charging the battery properly.

 

I would prefer not to go to the local garage and bend over, telling them I don't know what's wrong with it, and am happy changing the battery myself as long as I am confident that is where the problem is. I have seen the recommended Varta E44 battery on the forum.

 

Thanks again

 

Andy

If that is your original battery then you have done very well to get to this age without changing it. Try Eurocar parts, just enter your reg on their site and it will give you options on various batteries. Then look at the specification of each battery and go for the one with the highest cca (cold cranking amperes). That is always the best buy, Varda or name like that which I believe is Bosch anyway, stand to be corrected. Do not go to the dealer as they will only put in like for like at a much higher cost as you guessed.

Cheers Danny,

 

That was pretty much what I thought, but just wanted to reassure myself it wasn't a charging problem

If you don't check alternator first - before spending money on the new battery - you can't be sure it's battery at fault.

Of course upgrading battery - if it's original - won't hurt 

Edited 15 February, 20179 yr by jafo

If you have a multimeter just measure the voltage across the battery before it's first start of the day. A figure of 12.6 V seems to be a healthy figure for the battery with the engine off. If the alternator is working, when you start the engine the voltage will climb to about 14 V. Thanks to the smart alternator in a lot of new cars if you keep monitoring the voltage it may drop back as the alternator is switched off to save fuel once the car thinks the battery is fully charged. This does mean that if you change to a bigger capacity battery you may need to program the car to tell it this or it won't maintain the battery correctly. I think this is only in the Mark 3 Superb and Octavia, but it's something to check for peace of mind before changing.

You can get the battery tested as I'm sure you are aware, but so long as your battery has sufficient charge (so after a good run or external charge) at the time of testing, your alternator can also be tested.

I learnt this at my last visit to Halfords, for tyres. (It was another customer that had broken down and the mechanic told him his battery was fine, but it did not have enough charge in it for an alternator check).

 

It is very possible that your battery has a good few years in it yet, especially if the cold weather did not kill it off.

It may well just need a good charge, as if using your lights most of the time, combined with starting the engine requiring a good lump of power in the diesel, It doesn't get a good chance to charge.

 

Could invest in a 4 watt solar charger for 'laid up' days, maybe.

Just a quick follow up, which hopefully will prove interesting/useful to some as I learned something new.

 

Did a bit of googling, and found a number of suitable batteries. Checked my documentation, and couldn't find a radio code- no surprise there. Reading the radio notes supplied, it is unclear whether the code needs to be re-entered after the battery was disconnected or not. I really didn't want to take that chance as a new code is a complete pain. So I gritted my teeth and decided to pay slightly more for the battery and an extra tenner for fitting and ordered one from Halfords, just to be safe. I drove up to Halfords and everything was fine until I asked about the radio codes- where the duty manager informed me they don't guarantee it and it's 50:50. Delving a little deeper they don't maintain charge with a second battery or memory storage device. They simply take out the old battery and put the new one in. I told them not to bother.

 

Round the corner is one of those local discount motoring shops, who advertised free battery fitting. I decided to pop in on spec. and see if they could help. The guy showed me a perfectly suitable battery, and we got down to the issue of the radio code- and here's where it got interesting (about time too!). He said with it being a diesel you can simply change the battery with the engine running and everything is fine.

 

So they did.

 

And it is.

 

I never knew that, and didn't come across it on any of my internet searches.

The radio is coded into the dash control unit. There's no problem with disconnecting the battery and reconnecting it provided you don't change the radio/instrument panel hardware.

4 hours ago, andywatson3 said:

[...] He said with it being a diesel you can simply change the battery with the engine running and everything is fine.

 

So they did.

 

And it is.

 

I never knew that, and didn't come across it on any of my internet searches.

Because diesel engine doesn't need electricity at all to run

Only when you start the engine glow plugs could be used to warm up the air inside cylinders to help start engine quicker - but when engine is running - there is no need for the electricity as air is compressed so much, that when fuel is injected - it just explodes (that's just very simple explanation )

Good luck with that.

1 hour ago, psycholist said:

The radio is coded into the dash control unit. There's no problem with disconnecting the battery and reconnecting it provided you don't change the radio/instrument panel hardware.

 

This is what the manual sort of said, but was so unclear I really didn't want to risk it.

 

So I could simply have pulled it out anyway?

A

6 hours ago, andywatson3 said:

[...] He said with it being a diesel you can simply change the battery with the engine running and everything is fine.

 

So they did.

After a quick discussion with my brother - very good mechanic - YOU SHOULDN'T DO THIS !!

You'll fire alternator or other electronics in your car.

4 hours ago, jafo said:

Because diesel engine doesn't need electricity at all to run

Only when you start the engine glow plugs could be used to warm up the air inside cylinders to help start engine quicker - but when engine is running - there is no need for the electricity as air is compressed so much, that when fuel is injected - it just explodes (that's just very simple explanation )

 

That used to be the case way way back when with mechanical fuel injection. All PD and CR diesel engines are electronically controlled/fired 

 

With the battery disconnected you are running a great risk leaving the engine running depending on the alternator control system.

 

I've known a Ford Mondeo boil it's battery when fitted with a slightly different alternator

 

 

You can only boil the battery if the alternator's regulator is broken and outputs more than 15V. 

All the good ones have the nominal voltage between 13.5V and 14.5V but any battery can accept even 15V

What makes the alternators different is the maximum power .

You are right about running without the battery, it is dangerous and you can fry a lot of things. The battery acts like a stabiliser for all the spikes that the alternator can give in the system and without it all these hit the electronics, which in normal case has HW andSW protection but don't bet on it in all cases

The only thing such battery shops know about is selling product. Installation should be kept to professionals. It's not all that difficult, though.

 

What baffles me is that with all those batteries in the shop (and surely battery accessories like alligator clips if not radio code savers) they couldn't hook a secondary battery to the terminals in fear of losing radio codes.

On ‎16‎/‎02‎/‎2017 at 14:10, andywatson3 said:

Round the corner is one of those local discount motoring shops, who advertised free battery fitting. I decided to pop in on spec. and see if they could help. The guy showed me a perfectly suitable battery, and we got down to the issue of the radio code- and here's where it got interesting (about time too!). He said with it being a diesel you can simply change the battery with the engine running and everything is fine.

 

Was that 'Bodge it Boris' that you spoke to at the shop, or 'Wreck it Ralph'?

 

I hope you don't have any issues down the line because of this.

8 hours ago, Racataian said:

You can only boil the battery if the alternator's regulator is broken and outputs more than 15V. 

 

Indeed,

 

If you fit an electrically different (although mechanically the same) alternator that is lacking in a reference voltage then the alternator could have an unregulated output

 

I have a friend with an old Morris Bullnose where you had to turn the charging off manually - if you forgot after a while you could hear the battery starting to bubble!