[850] Best battery practices for infrequent use

ToriWhite · Post by **ToriWhite** » 25 Jan 2023, 15:53

What's the best way to handle the battery in a volvo that's driven barely once or twice a month?

It's currently in the state of 'If you want to drive it, you gotta jump it first' : besides the hassle of having to get a jump to start the car, I can only imagine it's doing a number on the batteries' longevity / capacity.

I've seen those wall units you can plug in to your outlet that charge your battery or keep it topped up, has anyone just let their battery sit on one of those until its needed?

Is the only solution around this to drive it around the block for 10m once a week?

Cheers, any thoughts appreciated

Post by **Sveedy** » 25 Jan 2023, 16:10

Seeing as these cars seem to like a full charge, I keep mine plugged into a trickle charger when I'm not using it more than once a week.
I'm pretty sure the PO let it sit for more than a month at a time, so they installed the charger.
https://www.cabelas.com/shop/en/schumac ... lsrc=aw.ds

Not the exact one I'm using but basically the same.

Post by **scot850** » 25 Jan 2023, 16:51

I do the same. My R has an aftermarket Viper immobiliser and remote start which drains the battery in about 2 weeks. The car is also in hibernation for our winter so it is sitting on slave tires and has a trickle charger connected.

Neil.

ToriWhite · Post by **ToriWhite** » 25 Jan 2023, 18:05

Sveedy wrote: ↑25 Jan 2023, 16:10 Seeing as these cars seem to like a full charge, I keep mine plugged into a trickle charger when I'm not using it more than once a week.
I'm pretty sure the PO let it sit for more than a month at a time, so they installed the charger.
https://www.cabelas.com/shop/en/schumac ... lsrc=aw.ds

Not the exact one I'm using but basically the same.

Thinking that doing a regular lap around the block might actually be my best bet. When you don't have the luxury of a garage to park your car in, using one of these would mean I disconnect the battery and have it sit on a charger in some corner of my already 'economy' sized apartment, and then lug it down and reconnect it when needed... vs the inconvenience of having to take 15 min a week to drive in a circle? both of them seem nearly equally annoying! Not more annoying than having a bricked battery, though

Post by **abscate** » 25 Jan 2023, 18:18

You can put a knife switch on the negative and disconnect the battery between uses

WhatAmIDoing · Post by **WhatAmIDoing** » 25 Jan 2023, 18:21

Driving once a week is probably the best. In my experience, these cars don't like sitting for extended periods of time. If you want a charger, I'd recommend a more expensive battery maintainer. Those cheap trickle chargers tend to wear batteries out if left on for long periods of time. Lead acid batteries don't like being kept fully charged with no load on them, and they also don't like being run dead all the time. AGM and deep cycle batteries tolerate extreme voltage swings way better.

Personally, I just pull the battery out of my daily and use it to start my cars that sit.

Post by **abscate** » 25 Jan 2023, 18:43

Good 5 amp trickle charger if car is used less than weekly. Really no Other option. A 15 minute drive might not be enough to charge

Epic story here

viewtopic.php?t=100794&hilit=1999+v70+battery+drain

You probably need 30 minutes drive, which is better for the engine too. Begging the question a bit, if you don’t drive 30 miles a week, why own a car?

Post by **matthew1** » 25 Jan 2023, 19:05

I used this trickle charger viewtopic.php?p=538569#p538569 regularly during Covid lockdown times when I wasn't driving. I've used it on and off before and since then. I've had it for about ten years now, no problems.

ToriWhite · Post by **ToriWhite** » 25 Jan 2023, 19:51

abscate wrote: ↑25 Jan 2023, 18:18 You can put a knife switch on the negative and disconnect the battery between uses

That wouldnt be hard to pull off, even without a knife switch just detaching and reattaching one of the posts on use. I wonder if that'd make a meaningful difference, though? I thought that the major loss of charge over time was that batteries just 'lose charge' inherently, not that the idle upkeep made any meaningful draw. I mean what is it doing left plugged in, flickering an anti-theft LED every 3 sec and keeping the dashboard clock running?

Post by **abscate** » 25 Jan 2023, 22:31

There are a bunch of processors that can periodically wake up on modern cars so draws of 50-200 mA aren’t uncommon. The upper end of thst, 200mA, will pull a battery down 50% ish in one week