Do you need a battery maintainer?
Posted by Odd_Barracuda2963@reddit | askcarguys | View on Reddit | 12 comments
I recently got a new battery, and now my Honda CRV won’t start right away. I took it to the place that replaced the battery so they could test the new battery, and the battery and the alternator were good.
The mechanic told me that if I don’t drive my car a lot, it won’t charge the battery. He suggested I got a battery maintainer and that seems to have fixed the issue, but now I have to charge my battery every night in the garage. I’ve never heard of this before. Is this a thing? Should they replace the battery again?
One_Evil_Monkey@reddit
Really need to give a specific description of how much you drive, and what year the CR-V is.
Several factors come into play... like how long does the vehicle sit between drives? Once started, how long is vehicle driven for?
If the battery has gone from starting the vehicle on Saturday, then you can't start it on Sunday... then it may very well be that repeated short trips just a couple of miles to the store aren't enough to recharge the juice that was used to crank the engine.
There may parasitic draw somewhere.
Running the battery low to the point where it won't start the engine damages the cells in the battery.
Using a maintainer is not a bad idea. I use them. But I have a few things that don't get driven or used every day or for long trips. The maintiners keep the battery in good condition.
Odd_Barracuda2963@reddit (OP)
Thanks for the reply.
My CRV is a 2017, and I pretty much drive it every day, but just in the city. Usually not more than 5-10 miles (about 10-15 minutes).
One_Evil_Monkey@reddit
No problem, you're welcome.
Okay, so yeah... you're basically short tripping it.
That's not enough to keep the battery charged. It's also not long enough to burn off condensation in the engine oil, but that's a whole different subject.
No joke, the amount of charge your battery uses to turn over your engine, isn't replaced by a 10-15 minute drive.
Basically it goes like this: You start engine, used a little charge, drive 10 minutes with accessories like A/C or whatever going, get to destination, turn vehicle off. Start vehicle and repeat cycle to home. The alternator can't keep up with that and eventually the battery is going to be short on charge.
2 options are take it out and hit the highway for an hour once a week or keep the battery on a maintainer.
trader45nj@reddit
If it's getting major drain overnight or within a week with a new battery, then there must be a parasitic drain. You need to put an ammeter in series with the battery, then leave the car closed and undisturbed for 15 minutes so everything powers down and see what the current draw is. It should be around 50ma. If it's significantly more, you have a parasitic load somewhere.
Downvote_me_dumbass@reddit
Just get a battery kill switch. Easy to install and it will help stop your battery from being drained by your electronics.
JoelJoelStinks@reddit
I just unplug the battery. Just pull the negative terminal off. I don't drive a lot.
ProJoe@reddit
This is such bad advice for modern cars. Modern computers make constant adjustments to maximize the performance and economy of the vehicle.
If you're clearing that memory by disconnecting the battery its going to make your car run worse in an overall sense.
RingOk664@reddit
I keep a battery tender on my rat rod. It keeps the battery charged until I drive it.
TheKoziONE@reddit
Car battery should be able to sit for minimum 2 weeks before it has any issues. A month is more typical.
Hash-82@reddit
Ummm.... you say "overnight".
How often do you drive the car, or how long does it sit. Whichever is easier to answer.
If this is happening within 24 hours, you've got problems and the maintainer is just covering it up.
PS: Year model would be helpful.
Charming_Fortune_859@reddit
You're going to have to define what 'dont drive a lot' means in your case. Only say 5 miles a day, or 20 miles once a week for instance, mechanic most likely correct. Only once a week but 100 miles? Not needed.
I have my WRX on a trickle charger. But I only drive it once every 2 or 3 weeks, and it has an old battery. My Tacoma gets driven maybe 3 times per week right now (unemployed), usually 20-30 miles round trip, also old battery, no charger needed.
zylpher@reddit
There will always be a slight draw on the battery for clocks and ECU stuff. But unless you have a major drain, or don't drive for months at a time. I don't see why you would need one. At most just pull a cable off. Buy a clock and ECU memory won't kill a battery in a few days.