Who do we like for long-storage batteries these days?

The Concert Coach (2012 T&C) only gets driven about once a month (or less) and I've had trouble keeping it charged.  Apparently last time it went too flat and will no longer hold a charge from the trickle charger.  The battery is at least 6 years old (even if low mileage) so it doesn't really owe me anything.

Used to be that this was the kind of thing Optima yellow tops were good for, and I can't complain about the one in the Manic Miata.  However, it is also at least 6 years old and I have heard that Optima's quality has really dropped off in the last X number of years.  Plus, they don't seem to have a drop-in replacement for the T&C.

So who do we like for batteries with this use profile?  Thanks in advance.

Keep it on a battery tender whenever it's going to sit for more than a day or 2 without being driven.  Just about any half decent battery will last a long time when kept fully charged, especially if it's on a float charge 24/7.  Otherwise, the tiny bits of parasitic draw from the car's electronics will draw the battery down over time, leaving it to sit partially charged.  That will sulfate any lead acid battery to death (AGM or flooded) in fairly short order. 

Kill switch and a good AGM. I have all of my long term sitters on a battery cutoff, and they'll hold a happy charge for months and months. I tend to use Odysseys.

I have the house battery on the Westfalia hooked to the solar system so it trickle charges from THE POWER OF THE SUN.

I used a cutoff switch on the Ranger when it was in a similar situation. 

I've been thinking of adding one to Canyonero because it will sit up to a month at a time, but it has enough electrical gremlins that I don't want to mess with it if it's not broken.

A kill switch is a viable option.  If you do that, pair it with an AGM, as they have lower self-discharge.  However, I don't really like kill switches on modern cars.  It means the ECU gets a full reset every time, plus any other electronics.  IMO, that's a last resort if there's absolutely no way to keep a charger hooked up (or even a small solar charger). 

The problem with a cutoff switch is that (being a modern fully-loaded vehicle) there is a ton of stored but volatile information that is lost every time that the battery is disconnected.

Thanks for the input so far.

Just long term trims, really. And they should be pretty close to 0 unless you have a problem. The Targa Miata (running a PCM of similar vintage to a 2012 minivan, I suspect) doesn't care.

In reply to Keith Tanner :

...but also time and date, bluetooth device connections, radio stations, seat and pedal positions, driver preferences, navigation search history...

Time and date, sure - unless it pulls that off the GPS signal. I suspect most of the rest of that is kept in non-volatile flash memory. Have you tried disconnecting the battery to see how much amnesia the car develops? Our 2002 BMW doesn't forget seat positions, for example.

In reply to Keith Tanner :

Yes, I have several times, and behaviour is consistent with a full reset.

Which is stupid, I agree.

Then it's back to the trickle charger concept.

My current status:

For what it's worth, I heard the same rumors about Optima and scoffed when they sent me one for my F-250 Project Car. Still, I installed it, because I figured I should see it for myself. My truck has fairly modern electronics, and sits for 3-4 weeks at a time with no tender or special treatment. That's basically the worst-case scenario for a battery.

18 months later, it still starts every time and has no issues. We'll see if the trend continues, but so far I'm happy.

The quality problems were not rumors, we were unfortunate enough to be a dealer at the time. The return rate was astounding. A lot of them behaved like internal problems, like the terminals not being connected. We are a shop that's been dealing with AGM batteries for decades, because that's what Miatas came with for a long time, so it sure wasn't a matter of not understanding the chemistry.

I've been told they have improved but the scars remain and nobody has sent me a free one to test :) I won't put my own money into one if there is an alternative. 

Is the van parked outside, or near a window? Maybe a solar charger could work. 

Also, is the battery dead dead or can you charge it via another battery hooked to a charger?

mtn said:

Is the van parked outside, or near a window? Maybe a solar charger could work. 

Also, is the battery dead dead or can you charge it via another battery hooked to a charger?

It's parked inside but probably close enough to a window that I could do a solar tender, though the window is in an area that doesn't get many hours of light a day.

The issue isn't a tender - I have a cheap trickle charger that works fine.  The van's battery was flat dead earlier in the year, but I pulled the Miata's yellow top out of the trunk  and put the trickle charger on that (fully charged to begin with) and then ran jumper cables to the van so the yellow top was buffering the load on the charger.

A few days of that worked well enough to charge the van for self-starting, and I drove it around for a day or two.  As soon as I parked it again, I hooked it up to the trickle charger and left it that way for a month.  At the end of that month the battery is not dead flat, but will not throw the engine over.  It did spend some time dead flat earlier in the year, when it was cold, and I am assuming it was irreparably harmed by that.  As I said, the battery is almost 7 years old anyway.

I think I'll order the Odyssey and maybe a second tender.  Thanks for everybody's help!

In reply to Duke :

A battery costs about $100-200 and lasts about 5 years.  That works out to be $20-40 a year. 
   Push it beyond that and you risk a low voltage High torque situation which just eats up a starter motor. 
   Replacing a battery is always easier than replacing a starter motor. 
    Is this a case of Penny wise and pound foolish?  

Also related, we have a video about extending the life of your battery:

My AGM is on a full kill switch and it still can self discharge in the off season without a tender. 

frenchyd said:

In reply to Duke :

A battery costs about $100-200 and lasts about 5 years.  That works out to be $20-40 a year. 
   Push it beyond that and you risk a low voltage High torque situation which just eats up a starter motor. 
   Replacing a battery is always easier than replacing a starter motor. 
    Is this a case of Penny wise and pound foolish?  

This is the first time I've ever heard of this. I'd assume the relay would just click if the voltage is too low... never heard of any possible starter damage. Anybody else care to weigh in on this? 

Saron81 said:

frenchyd said:

In reply to Duke :

A battery costs about $100-200 and lasts about 5 years.  That works out to be $20-40 a year. 
   Push it beyond that and you risk a low voltage High torque situation which just eats up a starter motor. 
   Replacing a battery is always easier than replacing a starter motor. 
    Is this a case of Penny wise and pound foolish?  

This is the first time I've ever heard of this. I'd assume the relay would just click if the voltage is too low... never heard of any possible starter damage. Anybody else care to weigh in on this? 

If the voltage is dipping excessively it'll be a little rougher on the starter.  But I wouldn't be too concerned about it.  Paying attention to the condition of a battery as it gets older is a good idea, but just having an old battery isn't going to kill a starter.  If that extra amperage were a death sentence, I'd expect to see starters failing constantly in cold places during the winter (cold battery puts out less power, plus engine with cold, thick oil is harder to turn). 

In reply to rslifkin :

That is exactly what happens up here in the Arctic  tundra.   Come fall parts houses stock up on batteries and starters. 
i replaced my battery every 5 years. And 20 years 379,000 miles  later the original starter went to the junkyard still spinning the engine over.  

frenchyd said:

That is exactly what happens up here in the Arctic  tundra.   Come fall parts houses stock up on batteries and starters. 

Interesting.  It gets cold here, but I only ever hear of it being a battery issue (marginal battery + temperature induced capacity loss = no start).  I've yet to hear of it as an issue for starters.  In general, it's logical that higher amperage through a starter will make it run hotter internally and shorten its life. 

In reply to rslifkin :

A fair amount of the time the problem is just with the bendix. But since there is more profit in replacing the starter, that's what happens. 
 as far as cold, at least once a year it hits 40 below  here and those cold temps really suck the life out of batteries.  Yet people need to get to work and••••• 

frenchyd said:

In reply to rslifkin :

A fair amount of the time the problem is just with the bendix.

Ummmm, since the bendix is a 100% mechanical device, I fail to see how low battery voltage affects it in any way.