Battery drain?

[Volvo6]

What is a realistic amount of time for a V70 to be left before the battery goes flat?

I’m finding I’m not not driving my V70R these days much and struggle to drive it enough to give the battery a good charge. Ideally I’d put it on a charger it’s not always convenient with other cars in the garage etc. Just wondering how long, with a healthy and charged battery it should be possible to leave the car before it goes flat?

I have a few similarly aged cars and seem to suffer less with drain. For example my dads 97 T5 seems to be able to sit for longer, my BMW E36 can go for weeks without being started (although the alarm is disconnected and it has a very large battery), even the Range Range P38 will go a couple of weeks with no issue, but the R struggles after a week or so!

Not done any drain tests yet but just wondering what is realistic from peoples’ experience?

[Dippydog]

My V70 will go at least a month as will my Omega,just at present my 960 will not go 5 days but tests have shown that's the battery that's on its last legs.

[4x4]

I recently spoke to the original owner's son about my 850 and he mentioned it suffered from battery drain and would need looking at. I think because they kept the car unused for many months at a time the battery just drained and died. There are several receipts for replacement batteries throughout their ownership.

I've left the car unused for 4 weeks and not had any problems and now that it's off the road for the winter I'll put the CTEK on every couple of weeks for a few hours to top it up

[turboboy]

Presuming that the battery is OK (around 12.6v at rest) then it could well be a "parasitic draw" from a faulty component.

I have had this on a number of my cars including the V70 (front passenger door light not turning off when shutting the door); BMW E46 (alarm); BMW X5 (aftermarket reverse camera combined with a faulty new battery; VW Golf (alarm).

For the Golf I bought a couple of meters to measure the current draw (Amps) through the fuses. (Had to buy two due to two sizes of fuze). The procedure was replace one fuse at a time with one of the meters and place the meter on the dash so that it could be read from outside when the car was locked. Left the car overnight to give the electronics time to shut down (some cars do not immediately close down when locked and can take 15-20 minutes to self check).

Went through the whole of the fusebox over a couple of weeks to the point that I only had the alarm circuit left, tucked away underneath the dash and difficult to reach with the fuses secured in place by plastic tie wraps. Just pulled these fuses and didn't bother to check with a meter but after a week the battery was still OK with no drain apparent and has been fine ever since.

Sorry if a bit long winded but Eric the Car Guy on YouTube explains it well: https://www.youtube.com/watch?v=KF1gijj03_0

[Clan]

Originally Posted by Volvo6

What is a realistic amount of time for a V70 to be left before the battery goes flat?

I’m finding I’m not not driving my V70R these days much and struggle to drive it enough to give the battery a good charge. Ideally I’d put it on a charger it’s not always convenient with other cars in the garage etc. Just wondering how long, with a healthy and charged battery it should be possible to leave the car before it goes flat?

I have a few similarly aged cars and seem to suffer less with drain. For example my dads 97 T5 seems to be able to sit for longer, my BMW E36 can go for weeks without being started (although the alarm is disconnected and it has a very large battery), even the Range Range P38 will go a couple of weeks with no issue, but the R struggles after a week or so!

Not done any drain tests yet but just wondering what is realistic from peoples’ experience?

Volvo recommend charging a new car battery every 3 months when in storage and every 2 Weeks in the current low usage conditions ....

you need to measure the leakage current when locked, alarm on and left 15 mins.. 50 ma is ok it will probably be less... three figure ma figures is not ok ..

[Luxobarge]

I'd reckon that 2 or 3 weeks minimum should be expected before any problems, with a good battery should really be longer still. So it's either a weak/dying battery or you have parasitic drain - as above, test for the latter, it's easy enough to do and then at least you'll know.

You still need to eliminate parasitic drain, but I'm a great fan of using maintenance chargers on vehicles that rarely get used. I have loads of vehicles all with chargers, and they've paid for themselves many times over in preserving batteries that would otherwise have had to be replaced several times.

[ITSv40]

Agree with Luxobarge regarding battery chargers. My son restored a XR3i convertible 12 years ago to concours and at the time fitted a new Motorcraft battery. The car has had little use since and has always been connected to a CTEC charger. The battery is still good and the car is always ready and willing to start.

[Clogs]

My 1999 T5 has a Volvo battery and when left for a fortnight in the airport car park has always started first go. You need to put a meter across from the positive to some metal work (negative) to see if any current is being used. Nothing shows up on my car, despite the alarm light blipping away.

[Luxobarge]

Originally Posted by Clogs

You need to put a meter across from the positive to some metal work (negative) to see if any current is being used.

If the meter is set to volts, that will just show you the battery voltage. If it's set to amps, it'll overload the meter.

You need to take the negative lead off, and put the meter between it and a body earth, with the meter set to amps this will show you what current is being drawn. Don't switch on anything while it's like this, as again it could overload the meter.

[Clogs]

Thanks - sorry I forgot to say disconnect the negative lead... thought it was obvious!