Age old automotive battery question.

Hey! I know this question gets tossed out there nearly as much as the  "what oil" question does but................ the batteries in both the Miata and the Mercedes are getting a little tired and need to be replaced. Both cars sit a lot and only get  driven in summer. This seems to really kill the batteries.  I do have a trickle charger but I don't leave it on them all the time as I am gone a lot and just don't want an electrical device hooked up when I am not around.  Ya I know I am weird. What's currently good? Optima batteries seem to have people that love them and an equal amount that hate them. What's everyone recommend these days??  Thanks.

I run a CTEK charger/maintainer on my viper and my truck in the winter, used to use it on my Corvette.  Before that I would kill AGM batteries even unhooked in 2 yrs or so.  

Probably about 18 years ago i bought a new yellow top optima for my daily driver. A few months later i bought another for my 4x4. The one in my daily driver was toasted dead in less than a year with zero pro-rating or warranty left(had 6 months warranty for that overpriced battery), the one in my 4x4 lasted somewhere around 12-14 years. At cost, at the time, those batteries were about 150$. 

Now if i need a battery i get a interstate battery from work(at cost) or just go to walmart. 

I know there's a lot of hate on optimas, and I've managed to seemingly kill one in the xB, courtesy of 3 bad starters and a bad alternator. But that dead optima is 3 years later powering a BG chassis project. If you run one in parrellel with a good battery and hook them to a trickle charger, then remove the good battery in 30-45 minutes and leave the trickle on for 3-4 days they come back. I have 3 cars running previously dead AGM spiral cells now, including one 9 year old battery. (I purchased 2 cores to bring back to life). Now the AGMs are all rated north of 575CCA and the BG cars call for less than 400CCA, but for my use, they can't be beat. 

Are you disconnecting the batteries when the cars aren't in use?  Leaving them connected on newer cars will run them down since there's stuff like radios or clocks that are always drawing power.

stuart in mn said:

Are you disconnecting the batteries when the cars aren't in use?  Leaving them connected on newer cars will run them down since there's stuff like radios or clocks that are always drawing power.

I use to take them out and store them in the basement during the winter but that got really old especially with the Mercedes which requires different codes put in after the battery is disconnected.  Now I will run a trickle charger on them from time to time and actually run the motors up to operating temp about once a month during winter. The batteries are both about 5-6 years old so I really can't complain too much but I am willing to pay more for a new battery if it's worth it. I hate going in the garage on a nice sunny morning for a quick spin to the store  and having to jump the battery first. I know the newer Mercedes actually have an additional plug in port to keep the battery charged if they are going to sit any length of time..............so much stuff is running even with the car off. 

Feedyurhed said:

I do have a trickle charger but I don't leave it on them all the time as I am gone a lot and just don't want an electrical device hooked up when I am not around.  Ya I know I am weird. 

I must live dangerously, I run 4 trickle chargers all winter. 

Yeah,  trickle chargers are only putting out at most like 2a, and some are putting out 0.3. Even at a dead short they're not going to make much heat so the chance of burning down your house is pretty tiny. 

Take care of your battery and your battery will take care of you, most of the time anyway. 

My bike has a mfg date of 9/99, and the original battery. It gets heavy usage for 7 weekends a year between April and Sept.  Then it sits through the NH winter.  It use to come in side and sit in the basement, but I have not done that in years.it stays in the unheated garage.   It does get rotated on a battery minder brand charger, about a week every month over the winter. 

I think the minder has a lot to do with it, it's a desulfating charger.  

YMMV, I will buy another batt minder when this one dies.  

Anyone keeping a fleet of infrequently used vehicles should read this:

http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

A battery will lose a fraction of its charge every day it sits. A partially discharged battery will tend to sufate and lose the ability to take a full charge.  It does not harm a lead-acid battery to be kept on a float charger constantly.  My advice would be to buy and use a battery maintainer.. 

Shorai. Fantastic battery, I'm 8 of them deep (lots of cars and bikes :) and zero negative experiences, <5lbs. Only one I've had fail was 7 years old, and had never been charged with their special charger. 

Carbon said:

Shorai. Fantastic battery, I'm 8 of them deep (lots of cars and bikes :) and zero negative experiences, <5lbs. Only one I've had fail was 7 years old, and had never been charged with their special charger. 

Hey Thanks.  Never heard of that brand but I am going to check them out.  

I have a bunch of cars, many of which see very limited use, and there's no way I could keep them all hooked up to a trickle charger.

But I bought a Battery Minder desulfating charger, for like $90, and I have been amazed.  When one of the cars gets to the point it won't crank, I put the Battery Minder on it for two or three days, and I'm back in business.  I have two cars with garden-variety lead plate/acid batteries in them that I bought in 2009, and they're still working just fine with one or two desulfations a year.  We have a spare battery for starting the whole-house generator that's even older than that, but I can't remember exactly when we got it.

JBasham said:

I have a bunch of cars, many of which see very limited use, and there's no way I could keep them all hooked up to a trickle charger.

But I bought a Battery Minder desulfating charger, for like $90, and I have been amazed.  When one of the cars gets to the point it won't crank, I put the Battery Minder on it for two or three days, and I'm back in business.  I have two cars with garden-variety lead plate/acid batteries in them that I bought in 2009, and they're still working just fine with one or two desulfations a year.  We have a spare battery for starting the whole-house generator that's even older than that, but I can't remember exactly when we got it.

Hmmmmmmm......Interesting. Thanks.

and what about storing batteries on a concrete floor ?

In reply to californiamilleghia :

Not a problem.  That myth / concern was from very old batteries (before plastic cases) where they weren't necessarily well sealed.  

I keep mine on a ctek all winter.  The MINI battery is the 13 year-old original, works fine.

I should probably get some kind of charger for the MPV.  Owned since new (2005), and driven daily, I have put a new battery in it every three years, like clockwork.  When the OEM battery died, I figured it was a bad battery, but every battery since then (and they've been several different brands) have died in almost exactly the same time frame.  I attribute the short battery life to power sliding doors.