12V Battery woes

[racer26]

So it seems my 12V battery can't hack it in the Canadian winter anymore.

Looking at battery prices, similar sized "automotive" batteries are in the ~$100 range.

I have a great deal of experience from competition robotics with SLA/Gel-Cell/AGM batteries of a 12V 18AH variety, that are slightly smaller than the OE battery. These batteries are commonly used in Uninterruptible Power Supplies and the like. Models like Enersys NP18-12 and similar.

Anybody had experience running our cars on one of these?

[Cobb]

What temperatures will this battery face? -60 F? I use to work for a company that sold hybrolic(SP?) equipment and once below -40f you were screwed as there was nothing to do but break hoses and wait it out.

Typically a bigger battery handles the needs better as the temps get into the extremes either direction. My advice is buy the biggest that will fit. Others say go for the u1 lawn tractor battery. Just the other day I saw some gel cell u1 at harbor freight for 70 bucks each. I used those in a few wheelchairs I had.

[racer26]

Originally Posted by Cobb

What temperatures will this battery face? -60 F? I use to work for a company that sold hybrolic(SP?) equipment and once below -40f you were screwed as there was nothing to do but break hoses and wait it out.

Typically no colder than about -35C. In the summer we can get up into the +35C range. (-31F-+95F)

[jc2bg]

I don't know where you're shopping batteries, but a lot of people on this forum suggest using a lawn tractor battery. Some of those are not very powerful, but you can buy several grades within the same or similar size, and my local Tractor Supply store carries 6 grades, up to 450 cold cranking amps in the same size, and 550 cca in a slightly larger size. Even the most expensive of these is under $60 US, so you might consider trying that route. Typically batteries carry a free replacement guarantee up to X months, so if it doesn't get the job done for you, you can upgrade further or, I'm sure, get money back or store credit if you need to go another way entirely. These tractor batteries are used in various equipment all winter long, so it's not like there are special requirements for cold climates that they wouldn't meet...

[aisbell]

Originally Posted by racer26

I have a great deal of experience from competition robotics with SLA/Gel-Cell/AGM batteries of a 12V 18AH variety, that are slightly smaller than the OE battery. These batteries are commonly used in Uninterruptible Power Supplies and the like. Models like Enersys NP18-12 and similar.

Anybody had experience running our cars on one of these?

Since the OEM battery failed, I have used AGM batteries in my Insight for over 10 years. But I don't drive my Insight when it's cold enough that the 12 v. starter would be used, so I don't have that battery requirement. So I tend to buy a smaller capacity battery than the OEM battery with weight-saving as a goal. I currently use an Odyssey PC680, but it has only 16 Ah capacity which might be insufficient for cold weather starting. Larger Odyssey batteries are available, but these batteries are more expensive than flooded-cell batteries, in general.

Maybe a good compromise would be a Mazda Miata AGM battery. Its capacity is greater than the OEM battery but it weighs less than the Group 51 Civic battery. Apparently, all Miata batteries are AGM because they are in the trunk where the buildup of explosive hydrogen from a flooded-cell battery could be dangerous.

With any of these non-standard batteries, you'll need to add a little padding so the battery will fit snugly in the battery box. And you might need to move the negative cable from the firewall to an existing bolt on the aluminum battery box frame so that it will reach since these batteries tend to have the terminal positions reversed from the OEM or Civic battery. The positive cable should reach without modification.

[eq1]

Originally Posted by aisbell

....Apparently, all Miata batteries are AGM because they are in the trunk where the buildup of explosive hydrogen from a flooded-cell battery could be dangerous....

I don't think this is the case. The OEM battery is normal, but it has little vent hoses attached...