single battery for dual battery cars 2017 thread

[rpmooreii]

Read through all the battery threads I could find and am wondering what the updated recommendations are for a single battery on a dual battery car (73T). I had been using an Interstate MT-42 on a battery tender but it died after 4.5 years. According to all the local Interstate dealers around me, the MT-42 is no longer made. Seeking a good replacement that will not break the bank. The 2012 threads seemed to recommend a Miata gel cell from Wesco... are these still made? Are they the best option? Will one suffice (I live in socal and it does not get cold)?

Thanks!

...Roger

[Hugh Lindberg]

I run a single Interstate battery #911. After reading comments from others on this forum, I bought one instead of two. It has been working fine for two years. You can find it on the Interstate website, but not many dealers stock it.

Good Luck, Hugh

[rpmooreii]

Thanks Hugh. I assume this is the one to which you are referring:

http://www.interstatebatteries.com/p...~21-2147384906

I was wondering if there were any gel cell alternatives that might fit in the box as well.

Thanks!

[Hugh Lindberg]

Yes that's it. I'll probably try gel cell alternative next time, if convenient to do so.

[422flat6]

I run a single Odyssey PC925 AGM battery and keep it on an AGM-specific trickle charger. It's pretty lightweight at 24 lbs and sealed unlike the Interstate so there's no risk of battery acid overflow. It turns my 2,4L over very well in San Diego temperatures. Don't know how it would do in a cold climate.

http://www.odysseybattery.com/extrem...ery_specs.aspx

It's small so I have it wedged in place with German cardboard

[merbesfield]

Yes the "Miata" battery is still available. 8AMU1R. These are AGM batteries. Just bought two on Friday. The ones I bought are made by East Penn and re-old under many names, Deka is one. Cost me about $115.00 ea, but can be bought online for $99 delivered and no tax. I waited too long and had to have them. Since I buy from the manufacturer, I was able to request no stickers on sides so a little better looking and it I want to go so far as edmayo did and camouflage them w old stickers, one less thing to stop me. Yea, I will get right on that project ;-) I keep mine on a trickle charge and they work well. Cannot comment on no trickle charge survivability. These are replacing old acid batteries that died in my RSR. In the S I only run one of these with a single trickle charge. With having two I am not sure how to handle the trickle charge hookup. Not sure if charge current will flow through to the second battery or do you have to have two trickles? I also have a master electrical cut off switch so there is zero draw on the batteries while the car sits. I am sure this helps keep the battery full charged while it sits. I have never been let down using these batteries.

[ejboyd5]

Pardon me if this is taken as a rant, but I simply can not understand everyone's obsession with trickle chargers, battery maintainers, etc. I maintain approximately one dozen automobiles ranging from mid-1950s Mercedes to a 2017 Jeep. I routinely experience a useful battery life of approximately 10 years with a best to date of 17 years from an old Sears 36. These batteries are left in their vehicles year round in buildings exposed to all normal temperature variations. My only concession to battery preservation is the installation of a disconnect switch on all vehicles that are not daily drivers. It is my personal contention that chargers, maintainers, etc., actually shorten a battery's life by constantly disturbing its natural equilibrium. My 1969 Porsche is currently powered by a single Group 24 Die Hard that has been in place for about 10 years. If collector car owners would stop trying to keep their batteries at a peak and artificially optimal level I'm sure they would see an increase in overall life expectancy as long as they have had the common sense to isolate the battery from the car's electrical system when it is not in use. A battery disconnect switch is one of the best investments that can be made, not only for prolonging battery life, but as a safety measure for a vehicle that is not routinely driven.

[G69]

A battery disconnect switch is a good safety factor if it is a good quality unit and doesn't create resistance in the circuit. It is also two more connections that can be failure points in the circuit. As for maintaining a battery at "float voltage" with a high quality charger, it is proven to be beneficial to prevent battery from sulfating- a condition that leads to internal short-circuiting of the plates when the sulfate collects on the bottom of the battery until it reaches the bottom of the plates. I know from marine use where batteries are subject to heavy cycling that a fully charged battery (12.6v) will far outlast one living it's life at 50% charge (12v). Ten years is a very good life for a Die-Hard battery! You're doing something right, but it is not wrong to keep a lead acid battery topped up. The damage comes from a primitive 'trickle' charger that overcharge a battery and can shorten its life substantially. A good 'smart charger' with a 'float stage' will certainly prolong a battery's life. So does a cut-off switch or simply disconnecting the negative terminal does the same thing while offering a chance to see the condition of the usually hidden battery terminal post. Corrosion on the negative terminal is something that makes a battery work much harder. Of course the very best practice is to DRIVE them all monthly-