AGM battery

[flyingfarmer]

Anybody have experience with AGM battery in your RV? In particular the Optima yellow or blue top. Or I guess any other type of AGM battery. Any reason not to use them?
Thanks,
Dave

[christopherglen]

I have 3 AGM's (not Optima) on my trailer. They run the 3000 watt inverter charger as well as all house loads. IC pushed 150 amps in the AM on the generator to recharge them. Mine are rated C5 (in my case 85 AH * 5 charge rate - 425 amps each) Flooded are typically c/10 to c/20 charge rates.

[dezl_dr]

Put one in my tractor 10 years ago. Still there, working good.

[time2roll]

Have used a couple D31Ts. Be sure you have a converter that can properly charge AGM.
You need to see 14.4 to 14.8 volts during charging or they are doomed.

[tplife]

Another Optima Blue-Top fan here, I have the 55 AH model (they make others BTW). Best investment I ever made at Costco, even had a $40.00-off coupon deal. Going strong and kept in the garage with a float charger. An AGM can be SAFELY mounted away from thieves, under your dinette, upside down, unvented, and without an enclosure box or pan. They are put to use in systems seen on Travel Channel's Rock My RV with Bret Michaels. Here's our Blue-Top power supply with quick-disconnect fittings, dual-fusing, and accessory outlets. Power for whatever we need at the campsite through the use of voltage converters. Decals are to discourage theft, vintage '80s and compliments of Wizard Wear:





Chiefly to run this 200W waterproof sound system:

[MARKW8]

Used a blue top for 8 years in our Lance. It now has a Die-Hard (Platinum I think)
AGM grp 31. 210RC.

Mark

[pa_traveler]

Try best convertor lifeline battery.

[Dennis_M_M]

I have used AGMs for years. Last longer than wet cell batteries and require less maintenance. Internal discharge rate is negligible so they can sit for months with no issues. I had an Optima in a vintage race car that sat untouched for two plus years and then started the car with no issue.

[Veebyes]

Thought it was about time the AGM question surfaced again. If we did not go over the same subjects again & again we would have nothing to post about.

AGM user here too. 2010 Lifeline 4D. Quite happy with it. Figure I am about halfway through its useable life. Like the no maintenance & little power loss during 5 months storage each winter with no charging at all.

[reddwar]

Johnson controls bought Optima then built a plant in Mexico. Told the employees U.S. plant could not produce enough product & the plant in Mexico was built to supply Europe. But slowly & surely, the product lines began being transferred to Mexico. Well they closed the U.S. plant down. Here the quality is not what it once was.

[Denny___Jami]

pianotuna wrote:
Hi Coach,
An Optima has 55 amp-hours. Reserve capacity 140 minutes.

The newer Optima D31M Blue Top is rated at 75 AH and 155 reserve, the old ones I have are 55 AH. If I have to replace mine I will use the 75 AH.

Denny

[2oldman]

AGM posts

[Coach-man]

Thanks, it makes sense, kind of!

[pianotuna]

Hi Coach,

Don't confuse voltage drop with capacity.

Look at the number of amp-hours at the 20 hour rate. Optima is a great battery but has by its design less amp-hours per unit volume of space consummed. I.E. there is lots of empty space that could be filled with flat pasted plates.

Another good measurement for "house" battery banks is called "reserve capacity". Again Optima has less per unit volume of space occupied by the jar.

An Optima has 55 amp-hours. Reserve capacity 140 minutes.

A lifeline group 27 has 100 amp-hours, reserve capacity 189 minutes; the group 31 is 105, reserve capacity 195 minutes.

The group 27 is probably a similar overall "foot print" to the Optima.

If you compare the Optima with a flooded battery, voltage drop under heavy loads may be better (i.e. lower) because of the large surface area and low resistance of the Optima. Optima claims 350 cycles to flat dead. Other AGM makers don't recommend that sort of abuse, but have a similar cycle capacity. Of course, a flood battery can't tolerate being driven to flat dead more than a very small number of times.

If you compare The Optima with the lifeline, under heavy loads, it *might* have a slightly better voltage drop but not enough to level the playing field.

Coach-man wrote:
OK, I do not mean to steal the thread or sound like an idiot, BUT I am curious about the statement "Optima has the lowest capacity to foot print because of their spiral cells".. Everything I have ever heard about Optima's is that it is about the spiral design that gives them more power in the smaller foot print? I have purchased Optima's and by any measurement CCA's etc. they are smaller than a similar rated traditional battery, so I am confused as to where you got your information??

[John___Angela]

We have two group 31's in our little C. Excellent batteries and very little voltage drop under heavy inverter loads. Also seem to recharge quicker with solar. When our 6 volts die in our big coach we will replace them with four x 8 D's AGM's next year.