Flat battery - again

[swee'pea99]

Third time this winter, so it's not a deal-breaker, but I'd like for it not to happen at all. Is it just to be expected at this time of year, especially given that it has a very battery-unfriendly schedule: two starts, lots of full-fan/lights, maybe five miles driving - maybe it's just consuming more power every day than it generates? It's quite a small battery, but newish, I'd say - maybe 18 months? I had a new coil fitted a couple of years back...could it be that? My old Golf estate never had this problem, but then again I think the battery for that came off a tractor...

Like I say, it's not that big a deal. But any thoughts, advice, handy household tips, I'm all ears!

 

[Ming the Merciless]

Take it for a proper motorway speed run once a week Or have a trickle charger attached.

 

[fossyant]

You could get the battery tested before replacing it ? No lights on, e.g. boot or glove box

 

[sleuthey]

When coil packs brake down inside they tend to cause miss fires and stuttering no flat batteries.

I would suggest an “Italian Tune-Up” is in order.

 

[sheddy]

Is there another fault, causing a small but constant current drain when not in use ?

 

[Archie_tect]

Is there another fault, causing a small but constant current drain when not in use ?

The clock?

 

[sheddy]

Alarm systems can go wrong causing additional current drain and a flat battery.
If the car is safely located, try locking with just the key and not the remote.

 

[HMS_Dave]

Nothing a multimeter couldn't tell you. With the engine on, the reading at the terminals should be around 14.2v -14.5v. This indicates your alternator is at least charging correctly, start turning electrical systems on and measure, it should be able to keep up with the load from electrical systems. With the engine off, the battery should be around 12.5ish volts. Much lower than this could indicate an issue. Its not the only indicator of a knackered battery but it will put you in the ball park given your issue.

 

[swee'pea99]

Wow! Thanks everyone. Lots to think about there.

Take it for a proper motorway speed run once a week Or have a trickle charger attached.

I take it this is what sleuthey means by “Italian Tune-Up” . I suspect that would work, but it seems a bit sledgehammer-to-nut, and I'd be loath to resort to it.

You could get the battery tested before replacing it ? No lights on, e.g. boot or glove box

I could, but TBH I don't think it is the battery. It really isn't much more than a year old, and it was a well-reviewed brand from a proper supplier.

Is there another fault, causing a small but constant current drain when not in use ?

A fault? It's a Honda!

Alarm systems can go wrong causing additional current drain and a flat battery.
If the car is safely located, try locking with just the key and not the remote.

I might try this.

Nothing a multimeter couldn't tell you. With the engine on, the reading at the terminals should be around 14.2v -14.5v. This indicates your alternator is at least charging correctly, start turning electrical systems on and measure, it should be able to keep up with the load from electrical systems. With the engine off, the battery should be around 12.5ish volts. Much lower than this could indicate an issue. Its not the only indicator of a knackered battery but it will put you in the ball park given your issue.

Interesting. I was getting 14.8v, engine running. Does this tell me anything?

(I forgot to take other readings...I'm on crutches & opiates at the moment, so not perhaps the sharpest tool in the box.)

 

[fossyant]

14.8v means there is sufficient charge.

How often is it getting used. I'm running my car for 15 minutes every other day as its not going anywhere.

 

[Cycleops]

You may need to check the output from the alternator.

 

[oldwheels]

Have you checked the battery terminals for corrosion and also the earth connection at the chassis?

 

[Drago]

Smart charger. My car gets very little use and battery levels are a concern.

In my case the battery is under the boot floor. I bought a smart charger and connected it permanently to the battery and then tucked it safely away in a nook. I then fitted an SP21 waterproof socket to a discreet point on the underside of the rear bumper, chopped the plug off the charger, and ran the lead out through a grommet and soldered it up to the backside of the socket. I then made up a mans lead with an SP21 plug. Now when the car is standing unused I just plug it in to an outaide socket with no faffing with croc clops.

Alternatively, most smart chsrgers come with a loom that connects to the battery and you can lift the bonnet and plug your charger strsight in if youre not as fussy, anal, and have as much time on your hands as I do.

C Tek also do a battery monitor. Connect it up to your battery and you can use an app on your phone to keep an eye on the voltage via bluetooth.
A decent charger can be had under £30, theyre not expensive. You can even get them from the likes of Aldi, who often sell reasonable such items.

 

[Smokin Joe]

You may need to check the output from the alternator.

He's getting 14.8 volts with the engine running, so the alternator is ok.

 

[Deleted member 1258]

Wow! Thanks everyone. Lots to think about there.

A fault? It's a Honda!

Our lads got a 2006 Honda Civic, a couple of years ago he had the electrical gremlins in, what a performance, interestingly, when they had finally got it sorted he wouldn't tell me how much it cost him.