Optima battery - Why?

[gd540]

We will soon need to replace the single house battery in our RT 190P. I'm not especially inclined to do the mods necessary to add a second battery.

I've done some shopping and know I can buy a Group 27 rated at 115AH for $70 at WalMart or Costco. I can also buy a Group 27 Optima Blue rated at 66AH for around $200.

I understand there are advantages to the Optima including:
- faster recharge (sounds good!)
- more recharge cycles (but enough to justify the added cost?)
- no venting for fumes needed (not mounting it inside the coach so a non-issue for us).

None of these features motivates me to spend nearly triple the dollars for far fewer amp hours. Am I missing something?

All input welcome, especially from those who have gone the AGM route or anything other than a "standard" deep-cycle RV/marine battery. Thanks!

[markopolo]

I have always gone with the 115AH for $70 at WalMart or Costco type wet cell batteries. I'd like the AGM's for their simplicity but the wet cells sure offer a lot of amp hours for the low cost.

If battery access is really difficult or if the battery is inside then spend the extra money. It all depends on everyone's own budget of course.

[Ron J. Moore]

I've two of the 27's AGMs, both 110ah types. I bought them within a year of buying our RT 190P new in Nov '04. Shortly after I got our RT I could see build-up and I had to check far to much for my liking; I also had them in my boat, so I am well aware of regular checking and filling, etc. I bit the bullet and bought two on-line, delivered to the house (UPS guy hated me, ha). Matter of fact, the date of manufacture for these was about 45 days before; I installed them and have never thought about them again. I check the trays each summer, batteries look like the day I put them in. Would I do it again - in a nano second. Safe travels.

[booster]

Originally Posted by Ron J. Moore

I've two of the 27's AGMs, both 110ah types. I bought them within a year of buying our RT 190P new in Nov '04. Shortly after I got our RT I could see build-up and I had to check far to much for my liking; I also had them in my boat, so I am well aware of regular checking and filling, etc. I bit the bullet and bought two on-line, delivered to the house (UPS guy hated me, ha). Matter of fact, the date of manufacture for these was about 45 days before; I installed them and have never thought about them again. I check the trays each summer, batteries look like the day I put them in. Would I do it again - in a nano second. Safe travels.

What brand of AGMs did you get? Most I have seen in the group 27 are 100AH or less. We went with wet cells to get to 115AH, but at 110, the AGMs would be more of a consideration.

[Ron J. Moore]

Booster, I went and pulled the paperwork - they are 100's, the brand is PowerSonic. I ordered thru BatteryStuff.com, price was $180, no tax and UPS. Safe travels.

[Mike]

Hey Booster, I've got 2 GR27 AGM's and they're Dekas I believe, from East Penn Manufacturing.
I think they're each around 100 ah rated, but of course the ratings depend on the specs/load put on
them during testing, and it's not an industry wide standard as far as I know. So I'd say the ah ratings
aren't necessarily significant, unless you're able to make sense of the manufacturer's testing methods
when they rate their product.
Still, I'm happy with the "set it, and forget it" aspect of the AGMs. So far, they seem more than adequate.
btw, apparently, even AGMs shouldn't be sealed in a compartment, also as far as I can determine from
some internet browsing. They can also produce potentially explosive gasses, in spite of the reputation
as virtually gas free batteries (recombinant technology?).
Wet cells are probably the most electrical bang for the buck, if you don't mind the maintenance.

[Davydd]

If you check I think you will see a knockout hole in the cap closer for venting those Deka AGMs with a small diameter plastic tube. My Deka Group 49 AGM had one. The under the passenger seat older Sprinter vans had a vent hole for the plastic tube to vent to the outside through the floor. The plastic vent tube is common with motorcycle batteries.

[Mike]

Mine are stored in vented/open trays outside of the van body, but thanks for the info.
Very useful for the applications you mention.