Basic battery questions

[riverplace]

I need a new battery for my 17B. I only have room on back bumper for 1 deep cell. I would like to switch to AGM. Costco has an interstate 24 DC with cca 750, mca 940, rc 140 and ah 70. I occasionally camp maximum 3-4 nights without electric, I have a portable solar panel. Will this battery work for me? Mostly used for water pump, led lights, occasional maxi fan, maybe short furnace use. If not, where should I look for a bigger or better one? Is there ever a risk of overcharging with a go power solar panel, if left plugged in? Or overcharging if plugged into ac outlet for days on campground?
Thank you!

[HABBERDABBER]

A 24 VDC battery is NOT what you need, A 12VDC is normally used.
Previous posts answer many of your questions.

[Centex]

Originally Posted by riverplace

.... Costco has an interstate 24 DC with cca 750, mca 940, rc 140 and ah 70. ...

Can you post the link to that item?

It is quite likely that is a 12 volt battery, the "24DC" designating it is BCI Group 24 Size and Deep Cycle type.

Just FYI / for comparison, here's a link to the Interstate SRM-27 specs, the Group 27DC FLA battery currently provided by ETI as the 'base' single 12-volt battery. Note it is rated at 88 Ah (amp hours).

[Vermilye]

That appears to be a Marine dual purpose 12V battery, not a true deep cycle. 70 amp hours (the most important specification for using the battery to power a trailer) is not very much. I don't know if the Escape supplied battery box will fit a group 31 battery, but if it will, there are many choices that can supply between 100 - 130 amp hours.

If the solar panel is used with a controller, it will not overcharge the battery.

[Perry Butler]

Originally Posted by Vermilye

That appears to be a Marine dual purpose 12V battery, not a true deep cycle. 70 amp hours (the most important specification for using the battery to power a trailer) is not very much. I don't know if the Escape supplied battery box will fit a group 31 battery, but if it will, there are many choices that can supply between 100 - 130 amp hours.

For years we chose a series 31 AGM battery for our summer and weekend needs. The series 31 could power the furnace in our Scamp for 2-3 nights, whereas a series 24 only one night. A series 31 AGM was still in our Casita after 5 years of use and still strong. For those who don't need that much power a series 31 is a great choice, but you will have to buy a new battery box, since it won't fit in a box for a series 24.

Enjoy,

Perry

[gbaglo]

A new battery box should be cheap enough and fairly easily installed in place of the existing box on the rear bumper, but shouldn't be required.
I have a Trojan 27 TMX on mine, in original box , and a couple 40 watt solar panels. Running the furnace a couple nights in a row means I have to get the solar panels out.
https://www.trojanbattery.com/product/27tmx/

[brroberts]

If you really want 4 days of electricity, I’d agree with a group 31 battery for warm weather. In the cold I doubt you would get 4 days.

[alanmalk]

Originally Posted by brroberts

If you really want 4 days of electricity, I’d agree with a group 31 battery for warm weather. In the cold I doubt you would get 4 days.

Here is a link to an Odyssey group 31 AGM battery. (Top of the line. Now more expensive than many Lithium equivalents.) We used a pair of these batteries for 7 years with excellent service. But like others above, I believe that only 1 battery will not be sufficient in winter unless you have a big portable panel (150 watts+) and have plenty of sun. Go to google and search on "solar energy winter vs summer". Now, a really good solution would be to spend winter in sunny Mexico. (Please invite me...)
https://www.batterymart.com/p-odysse...t-battery.html

[riverplace]

Thanks for all the great information. I will look for a 31 AGM. I'm not camping in cold weather, but need a couple days to get to SW from Northern MN. This 31 should work for me and it will fit in the box I have mounted. I'll pull out the solar panel whenever I camp without hook ups.
When I google search for 31 AGM house battery, many of the batteries that come up are dual or marine/RV. I should stay away from these? Will I find anything for under $400?

[dfandrews]

We're another who upsized to a Group 31. It is 120 Amps, with thicker plates. The std. ETI battery box fitted only their stock Group 27 (as of 2015), but boxes are cheap, so we got two larger boxes. One has the Group 31, and the other has misc. stuff (clocks, chocks, etc.) that would otherwise have to be in front storage.

[riverplace]

Which brand did you decide on? The prices seem to be all over the place.

[dfandrews]

Originally Posted by riverplace

Which brand did you decide on? The prices seem to be all over the place.

In recent years, I've always gone to "Batteries Plus"; I got a Duracell Grp. 31. If you take your vehicle in, they'll do the install (without erasing your computer or radio memory!).

[Brian B-P]

Originally Posted by riverplace

I would like to switch to AGM. Costco has an interstate 24 DC with cca 750, mca 940, rc 140 and ah 70.

Originally Posted by Centex

Can you post the link to that item?

It is quite likely that is a 12 volt battery, the "24DC" designating it is BCI Group 24 Size and Deep Cycle type.

Yes, and this is an example of a "24DC" battery at Costco:
Interstate 24DC Marine / RV Battery
Item 850281
It looks like the Interstate M-24DC, with slight variations.
But these are flooded batteries, not AGM.

With the different specs, the one listed is presumably an AGM battery which does not appear on the Costco website. Interstate doesn't make batteries, they brand and distribute batteries made by another company, so specs and availability will vary.

Anyway, bigger than BCI Group 24 size would certainly be better.

[brroberts]

I typically buy a deep cycle wet cell battery and take care of it. That for me has been the lowest cost per use over the long haul. The exception for me has been AGM on my boats due to battery location. All of my RV’s have been wet cell. There are certainly newer technologies that some find worth it.

[Vermilye]

If I had to replace the rear bumper mounted batteries in my 2011 17, ZI would have gone to AGM because I had the problem that rough roads splashed enough acid out through the tops of the batteries to cord the wiring & leave a thin layer in the bottom of the battery box.

While I didn't have this problem with the 21C, I still would have replaced the flooded batteries with AGM to prevent the propane detector from sounding when the solar controller hit the batteries hard enough to make them off gas. Instead, I switched to lithium, and have been very pleased with the results.

[Brian B-P]

Originally Posted by riverplace

When I google search for 31 AGM house battery, many of the batteries that come up are dual or marine/RV. I should stay away from these?

Not necessarily. AGM construction works well for high current, so a dual-purpose AGM battery isn't as compromised to accommodate starting current demand as a dual-purpose flooded battery would be.

[CE Vogel]

I've had great success with Trogan flooded deep cycle batteries. I agree an AGM would probably work better due to the rough ride on the rear bumper. Here is a link to the Trojan size 31 AGM battery:
https://www.trojanbattery.com/product/31-agm/

[T2S]

Trojan batteries are pricey but I found there life to be great if you treat them well. Be sure to call around when purchasing. I found the best price at a local golf cart company, but the price varied by a large amount between the different companies I called.

[Brian B-P]

Originally Posted by Brian B-P

AGM construction works well for high current, so a dual-purpose AGM battery isn't as compromised to accommodate starting current demand as a dual-purpose flooded battery would be.

To expand on this a bit:
Optima is one of the oldest brands of AGM batteries - perhaps the original. Their products generally use their distinctive spiral-wound cell construction, but they're effectively the same as the flat-cell designs. They have three series:

• RedTop

  for starting applications
  with automotive tapered post terminals

• YellowTop

  marketed as dual-purpose (deep cycle and starting)
  mostly automotive post terminals

• BlueTop

  for marine applications
  most have dual terminals: automotive posts (for starter) and threaded studs (for other loads)

The difference between the series is mostly marketing - the only physical differences are the terminal types and available sizes. For instance, the REDTOP 34R ("starting") and BLUETOP 34M ("marine") are the same nominal size (BCI Group 34) and have the same specifications... including cranking current and deep-cycle capacity. Within this brand, it would make sense to just get the biggest size that fits and has suitable terminals... that might be the YELLOWTOP 31T or BLUETOP D31M

[riverplace]

I wasn’t able to find a Trojan battery in northern MN and the 31 AGM Duracell batteries at Batteries Plus are out of stock within a 200 mile radius, so I ended up with a 31M AGM Interstate that has 100ah and 3 yr warranty. My next question is, can I charge it with my trickle charger for 6 hrs (it has a 6/22 sticker on it, so I’m assuming it’s been sitting on shelf for awhile) and be assured that it’s fully charged? I don’t really want to buy yet another “smart charger”. Also, if I store fully charged in house over winter, should I occasionally put a trickle charger on it, or wait until needing to use? Batteries have gotten confusing, or is it just me?
Thanks!