Car Battery Life (and testing)

Car Battery Life (and testing)

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Discussion

mawallace

Original Poster:

184 posts

72 months

Sunday 18th November 2018
quotequote all
My car battery was dead on the first cold morning of the year!

As I was changing it I was wondering if there was anything that I could have done to pick up that it was on it's way out. Is it as simple as measuring the voltage when the car has been at rest once in a while?

Also, the car was 6 years old and it was the original battery. So what's the average life before they need changing? It was a VW Polo.

anonymous-user

53 months

Sunday 18th November 2018
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Ideally you'd want to hook up an amp clamp to either to positive or negative cables from the battery, and check the charge rate going into the battery from the alternator. There's kind of a knack for reading an amp clamp and/or battery tester that you only really pick up by dealing with a LOT of dead batteries, but generally a charge rate of 10Amps or below on a completely dead battery is what I'd consider to be pretty knackered. A healthy battery will take in at least 25Amps+ before starting to trail off, but generally over a period of 10 minutes checking the amp charge rate you can make a decent prediction as to the health of a battery.

A volt meter alone on a dead battery would only really be useful if the battery has a dead cell, which is fairly uncommon. It can sometimes help deduce if the battery has been drained or not, but its not a particularly reliable method in comparison to a good old amp clamp! (or a meter set to amps wired in between the battery and earth in series, but we're getting a bit complex there, LOL).

Although in my experience, if a battery has gone flat and there isn't a clear reason (a consumer left on, car used primarily for lots of very short journeys or car has been sitting for ~1.5 weeks+), the battery is duff and not worth messing around with.

You might be able to eek a few more weeks or months out of it, but it WILL fail again, and probably when you expect it the least. For the sake of what it costs, get it replaced or be at your own peril!

Edited by anonymous-user on Sunday 18th November 20:42

mawallace

Original Poster:

184 posts

72 months

Sunday 18th November 2018
quotequote all
Is there a better battery brand or should I go for a vw battery

Spare tyre

9,458 posts

129 months

Sunday 18th November 2018
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Usually the best value vs longest warranty

Typically I just buy the one with the longest warranty, but then I keep my cars for as long as possible

Eurocar parts / carparts4less with voucher codes offer some crazy savings from time to time

henrycrun

2,448 posts

239 months

Sunday 18th November 2018
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if you have a decent multimeter check for current drain. Something on your car may be drawing to much current.

cuprabob

14,419 posts

213 months

Sunday 18th November 2018
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mawallace said:
Is there a better battery brand or should I go for a vw battery
In my experience Bosch or Varta are good replacements, which used to be OEM for VW but they seem to be using Exide now.

Shop around though as the price varies a fair bit for the same battery.

As well as ECP / Carparts4less, check out Tayna.co.uk, as they are competitive.


anonymous-user

53 months

Sunday 18th November 2018
quotequote all
mawallace said:
Is there a better battery brand or should I go for a vw battery
Many Volkswagen batteries are made by Varta IIRC, so a top spec Varta should be as the same if not better than one in a VW casing.

https://www.tayna.co.uk/car-batteries/varta/d15/

Do double check the sizing for your particular Polo though!


Dr Doofenshmirtz

15,185 posts

199 months

Monday 19th November 2018
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6 years is pretty good going to be honest.
For a replacement - go to your local scrappy. They always remove the batteries and sell the good ones for around £15. I've never had a bad one.

300bhp/ton

41,030 posts

189 months

Monday 19th November 2018
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mawallace said:
Is there a better battery brand or should I go for a vw battery
I doubt VM make the battery, it'll be made by someone else.

Have a shop around and see the price differences. The choice is then yours on which one you go for.

Overall life is hard to tell, most will have a 2, 3, 5 or 7 year warranty. But it will depend on how it is used tbh.

6 years is probably pretty acceptable use.

And no, there isn't really an easy to spot when a battery isn't performing as well. It's down to how it performs under load. As you pull amps from a battery it's voltage will drop. The more knackered it is, the more the voltage will drop under the same use. The overall capacity can also reduce with time and use also.

hutchst

3,696 posts

95 months

Tuesday 20th November 2018
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I was having battery problems a few years ago with an X-type. The battery specialist told me that he could sell me a competitively priced replacement with a premium German brand label, that was made in China, or a more expensive one with the same premium brand label, same capacity, but made in Germany. My two failed batteries were Chinese.

It wasn't in the UK, but still worth checking what you're buying.

hutchst

3,696 posts

95 months

Tuesday 20th November 2018
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My current chariot is a 4-y-o Land Cruiser Prado, now on its third battery. Batteries ain't what they used to be, in my experience. But on the other hand, modern vehicles have a lot more going on electrically, and quite a lot of it doesn't switch off just because you park the car and leave it.

majordad

3,600 posts

196 months

Tuesday 4th December 2018
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My Cayenne 2013 Diesel has a voltage display. Sometimes when I drive it’s at 14.7V and others around 13.4 V.

What do the figures actually mean, are they the battery voltage or are they the alternator charge voltage ?

majordad

3,600 posts

196 months

Tuesday 11th December 2018
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Anybody?

mawallace

Original Poster:

184 posts

72 months

untakenname

4,953 posts

191 months

Wednesday 12th December 2018
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I use a cheap (£20) battery monitor which connects to my phone via bluetooth and lets me know what state it's in (and alerts when low), it also shows the voltage use whilst the cars on as well and can help diagnose the state of the battery and the alternator.



mawallace

Original Poster:

184 posts

72 months

Wednesday 12th December 2018
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Where did you get the monitor from?

NugentS

685 posts

246 months

Wednesday 12th December 2018
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untakenname

4,953 posts

191 months

Wednesday 12th December 2018
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Yep, that's the one. I'm pretty impressed tbh, had it a couple of years now and it's useful in winter as my weekend car has quite high parasitic drain (alarm mainly) and can sometimes go weeks without using so its nice to easily check the battery has enough charge.

Edited by untakenname on Wednesday 12th December 21:14

Dave.

7,324 posts

252 months

Wednesday 12th December 2018
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Oooof, they're setting off my nerd-alert!

I'd need 4 though, can you pair more than one at a time?

I have an android TV, should be in range of all the cars...

nerd

ninjag

1,827 posts

118 months

Thursday 13th December 2018
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Dave. said:
Oooof, they're setting off my nerd-alert!
Ditto! smile