Battery Drain Dilema

[Andy_Mac]

So decided to start going down the road of tracking down what is giving a slight power draw when the cars off causing the battery to go flat when not driven for a few weeks. 

 

Initial thoughts were to just get a cheapish solar panel and wire it up to permanent 12v. Won’t be enough to ever overcharge the battery but should hopefully do enough to make up for whatever draw is occuring. 

 

Other thought is i’m fairly sure the Tactrix under the dash which flashes it’s LED’s and whatnot even when the car’s off must have some draw and can’t see any need for it to be on. 

So thinking I could possibly connect pin 16 which has permanent power to a relay with a delay timer on the coil that’ll keep it live for x many minutes after shutting off auxillary power. Can’t see any downsides to this besides complexity and risk of something failing.

Only real concern was with flashing and logging issues but reckon the delay timer should alleviate any chance of butchering things in that sense.

 

Anyone in the know see any reason why either option would be a bad idea?

[Joker]

checked the common things like Power antennae not fully going down or interior lights?

[Batbaruman]

led flashing draining a car battery seems unlikely but then again, you do mention period of several weeks. does vehicle have an alarm? some discharge is quite normal. some form of trickle charger sounds like best idea? i ended up getting a ctek charger for mine, though if you park yours outside it may not be so practical.

[Andy_Mac]

Power antenna... Subaru’s haven’t had those since the stone ages... 

Interior lights are always off so not those either. 

Not so much concerned about the LED flashing but whatever else it might be doing to justify the indicator flashing. Has an AVS alarm so just as likely to be that. 

Have a CTEK one but would mean having an extension lead run across the main entrance to the house hence kinda thinking the dinky solar panel to atleast keep up with the draw for those times when it’s not used for a few weeks

[calebwrx]

8 minutes ago, Andy_Mac said:

Power antenna... Subaru’s haven’t had those since the stone ages... 

Interior lights are always off so not those either. 

Not so much concerned about the LED flashing but whatever else it might be doing to justify the indicator flashing. Has an AVS alarm so just as likely to be that. 

Have a CTEK one but would mean having an extension lead run across the main entrance to the house hence kinda thinking the dinky solar panel to atleast keep up with the draw for those times when it’s not used for a few weeks

I have an AVS too. Battery lasts 2 weeks at a stretch without driving it.  

[Batbaruman]

yep i have had aftermarket alarms on all my cars, before i installed them there was no significant risk of flat batteries but afterwards it just takes 2 weeks of not driving to drain it all.

[Loren]

I had the same problem, ruined 2 or 3 batteries, then got a 20w solar panel. Works perfectly.