BMW 3 Series Compact - Battery Starter Packs - meldrew

My car battery, still under warranty, in an old 3 Series BMW seems to be playing up. Tested by the supplier (it is a Varta brand) it usually shows as "battery good, needs charge" even after being charged fully (CTEK-MX5) a few days earlier. The voltage seems to drop quickly to as low as 12.3v and on a couple of occasions the engine turns over but with not enough welly to start the vehicle.

I am assuming it will ultimately fail (hopefully within warranty!) as the previous Varta did. In the meantime I do not want to be stranded somewhere where it will not start.

My question therefore is are those 12v self contained booster starters any good and does anyone recommend one? Budget about £50.

TVMIA

BMW 3 Series Compact - Battery Starter Packs - gordonbennet

My current (ho ho) booster pack was somewhat more than that but i did run a cheapy booster pack for many years when i was on car transporter work, the secret is to keep them charged regularly.

I suggest finding a Yuasa battery if the present one dies out of warranty, very good quality and long lived, up to 5 year warranty.

I had wonderful service from Varta batteries of yore, the one on my old Volvo Diesel estate my sister used to start her Volvo artic with via jumper leads when the thing died over the Christmas and Easter breaks, is it did every year without fail, that Varta was donkeys years old and indestructible, sadly as in many walks of life things aint what they used to be.

BMW 3 Series Compact - Battery Starter Packs - elekie&a/c doctor

£50 will buy you a "toy" jump start pack that may or may not start the car in times of trouble.If you want the real deal ,then I would suggest one of these .I started my neighbours Land rover Disco with one ,no problem.www.sipuk.co.uk/sip-03936-rescue-pac-1600.html

BMW 3 Series Compact - Battery Starter Packs - madf

Another vote for Yuasa.

Son's Yaris had Yuasa fitted as OE failed after 11 years.

My Yaris Yuasa was poor by comparison - only lasted 10 years.

BMW 3 Series Compact - Battery Starter Packs - skidpan

The voltage seems to drop quickly to as low as 12.3v and on a couple of occasions the engine turns over but with not enough welly to start the vehicle.

A healthy battery is at least 12.6 volts after standing if the battery voltage drops to 12.3 volts quickly while the car is standing the battery is past its sell by date and needs replacing. Even if it has enough power to crank the engine it will have insufficeint power reserve to provide power where needed to start the engine.

The Yuasa one I bought early in June has stood for 3 1/2 weeks now and still reads 12.87 volts. The battery it replaced was 8 years old (Exide) and would drop to 12.6 volts after a week, it failed to start the car on just one occation and I replaced it.

So forget a starter pack and buy a new battery.

Edited by skidpan on 01/08/2017 at 09:58

BMW 3 Series Compact - Battery Starter Packs - meldrew

Very helpful replies here and many thanks. We are probably in bangernomics territory here but the car runs well for 95k miles costs little in overall maintenance and did 40 mpg to Wales and back last weekend.

It clearly looks like the battery is the problem. As it still has nine months warranty I would like it to die properly as (with the previous one) the supplier would not believe it until his hand held tester said it was dead.

After 48hrs charge it was only showing 12.3 volts this morning and dropped to 12.0v turning the side lights on. The engine did however start easily.

The question is how to I get them to accept it is faulty? Or do I stop wasting my time (I have plenty!) and buy another one?

BMW 3 Series Compact - Battery Starter Packs - Cyd

Those hand held battery testers are notoriously unreliable. You really need to test a battery under load. You can do this yourself, all you need is a multimeter

https://youtu.be/AT_XmlwMVz4

If I were you I'd tell the shopkeeper that you want the battery tested properly with a load tester. I suspect he's using the hand held device as a way of deflecting warranty claims (which is odd, because he won't lose out anyway). If he won't, tell him you're going to get it done at a cost which you will claim back from him along with the cost of the new battery when it undoubtedly fails.

Before you go that route though, maybe email him to ask for it to be tested and expressing your belief it's failing in order to try and solicit a written reply which might be useful to you further down the line. Alternatively record your phone conversations - there are plenty of free apps. i use ACR.

 

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