8D AGM batteries

notsobright

hi everyone, Im considering for purchase an 8D AGM battery.

the two brands I have available locally are

Trojan: http://www.trojanbattery.com/Products/8D-AGM12V.aspx

Rated Cap., Amp. Hrs, 20 Hr Rate is 230, I have been quoted $461 for the Trojan 8D


and Lifeline: http://www.lifelinebatteries.com/rvflyer.php?id=8

Rated Cap., Amp. Hrs, 20 Hr Rate is 255, $567 for the Lifeline.



I dont know alot about them and would like some input on them since they have a rather large pricing difference.


please forgive me if Ive posted in the wrong forum but Im hoping this will turn into a review with some input. I will be using them as single battery (not in a bank) in an RV

thanks

Kamala

Re: 8D AGM batteries

I briefly considered the Lifeline 8D because, supposedly, Concorde "invented" AGMs. I decided against any 8D size battery because of the weight. They're too heavy for me to lift by myself. Instead, I went with the Deka 8AGC2. It is a 6V and weighs 70 lbs. Capacity is 220 AH but at the 100 hr rate. A local distributor had them for $180. 2 in series will give you 12V of 220AH @ C100 for $360.

I am coming to the belief that the C100 rate is more appropriate for RE batts. Even though it makes comparisons problematic.

In my system, I estimated that I would use 73AH/day (it's actually a little less.) 73AH/24H=3A. A 220AH @ C20 will reach 100% DOD with a constant 11A load for 20 hours. Who does this! A 220AH @ C100 will reach 100% DOD with a 2.2A load for the same time period. This is more in line with my usage. A 2.2A load on the C100's, will bring them to 20% DOD after 20 hrs. Which allows for the 4 hours of good sun to recharge.

I know these things are not linear and there's a Peukert effect. But C100 makes more sense since the DOD needs to be kept to 20%.

Craig

notsobright

Re: 8D AGM batteries

yes they are definately heavy! I ended up getting the Lifeline GPL-4DA:

http://www.lifelinebatteries.com/marineflyer.php?id=5


it wasnt the weight issue but the depth and where Im mounting it. they also have a "sun extender" line specifically for solar installations but those only have a 2 year warranty and the RV spec ones come with a 5 year so I went with the RV/Marine type mainly for that reason.

I will have it in my hand tomorro but wont have a chance for installation until next week.

thanks for your input Kamala

Cariboocoot

Re: 8D AGM batteries

notsobright wrote: »

yes they are definately heavy! I ended up getting the Lifeline GPL-4DA:

http://www.lifelinebatteries.com/marineflyer.php?id=5


it wasnt the weight issue but the depth and where Im mounting it. they also have a "sun extender" line specifically for solar installations but those only have a 2 year warranty and the RV spec ones come with a 5 year so I went with the RV/Marine type mainly for that reason.

I will have it in my hand tomorro but wont have a chance for installation until next week.

thanks for your input Kamala

A couple of observations for what they're worth:

There may be a significant difference between the Sun Extender and the RV/Marine, vis: the SE is a true deep cycle and the RV is a "hybrid" type and won't last as long in an RE application.

As for warranties, installing any battery in an application it isn't intended for (such as using an RV/Marine type in a Renewable Energy system) is enough to void said warranty.

I suspect the SE warranty is shorter because they know the kind of "abuse" the battery may take in that situation. But that battery would probably outlast the RV under the circumstances.

Sorry for "cheering you down".

notsobright

Re: 8D AGM batteries

I asked LifeLine before I purchased about the solar charging in an RV and they recommended the GPL-4DA and said the SunExtenders were not designed with vibration and extensive temperature variations as the RV type was.

measured 12.71 volts@ 84 degrees F right out of the box!

just finished mounting it but have some wirring todo before it goes online.