|
| Author |
Message |
Lovetheroad75
Member
|
# Posted: 24 Oct 2016 03:46pm
Reply
Has anyone used these big AMG batteries to store solar/wind electricity off grid? I found these on e-bay and they are listed way lower than anything I have seen but I wanted to see if anyone out there has any experience using them.
http://www.ebay.com/itm/DC260-12-Deep-Cycle-AGM-Battery-Group-8D-/331989196959?ssPage Name=STRK:MESE:IT
|
|
DaveBell
Moderator
|
# Posted: 24 Oct 2016 04:56pm
Reply
I use the Trojan 31-AGM's. They weigh 69 pounds and made in U.S.
|
|
Lovetheroad75
Member
|
# Posted: 24 Oct 2016 05:23pm
Reply
These are listed as group 8D and weight 170 lbs!!
HUGE!
|
|
MtnDon
Member
|
# Posted: 24 Oct 2016 05:50pm - Edited by: MtnDon
Reply
Generally speaking, real deep cycle batteries never have a CCA (cold cranking amps) rating. Generally speaking CCA only appears on a normal automotive starting battery or a dual purpose battery sometimes called marine/rv batteries. I suspect this battery is not what would be called a true deep cycle battery. That means it may not last as long as a true deep cycle battery would. Hence, it is cheaper.
FWIW, IMO, the term deep cycle is overused and misapplied to many batteries.
|
|
Lovetheroad75
Member
|
# Posted: 25 Oct 2016 09:20am
Reply
From what little research I have done (I admit that I am not an expert) there are 3 types of batteries. The deep cycle batteries are geared for long, sustained current that does not fluctuate a lot; then there are the batteries that are geared for cars/trucks, they are made to have huge spikes in current so that they can charge a starter; and then there are these AMG batteries that are "supposed" to be the best of both worlds. These particular batteries that I linked generally go for $600 - $800, and I found these for $299. Now they have been lowered down to $229 and it looks like this company is trying to clearance them.
|
|
MtnDon
Member
|
# Posted: 25 Oct 2016 10:26am - Edited by: MtnDon
Reply
Not quite... yes there are three basic groups in lead acid batteries; standard cranking battery = auto battery, designed to provide a large current for a short time. Harmed by deeply discharging.
At the other end of the spectrum is a true deep cycle. Thick lead plates. Can be discharged more deeply. In between, the third type, is a compromise battery. Plates are thicker than the auto battery but not as thick as a true deep cycle battery. Common to see them labeled as marine / RV batteries.
Those three types are available in flooded types, the ones with caps that are meant to be removable. Standard lead acid types can also be sealed as a maintenance free auto battery has been for decades. They may have a cap that can be pried off. Flooded batteries could be standard cranking, or true deep cycle or a marine / RV battery.
Then there are AGM types of batteries which are sealed. No caps, no way to check or add water. AGM have valves that will release excessive internal pressure. AGM's can be cranking batteries; I have them on my ATV. AGM's can also be built as a marine / RV battery. My neighbor has them on his boat. AGM's can also be built as a true deep cycle. I have a friend who uses some off grid; Concorde brand IIRC. They are all AGM, and all built for different purposes.
There is also a third type which is a sealed GEL battery. You don't want those for off grid power.
Be aware that batteries start to age the moment they have the electrolyte installed. AGM age better than flooded cells. But they still age. So how old are those bargain priced batteries? Has the charge been maintained?
|
|
Lovetheroad75
Member
|
# Posted: 25 Oct 2016 03:06pm
Reply
Thank you for the info! Like I said, I am new at this and far from an expert! I do not know the answer to your questions about their age, I just know that they are listed as new/unused in the box. I was told that they were originally brought in to use with solar panels in the middle of oil fields, and that they are sealed and that the cover is corrosive resistant. They also said that the batteries are fully charged.
|
|
MtnDon
Member
|
# Posted: 25 Oct 2016 04:54pm
Reply
I guess one way to look at these is that the price of 230 is about 40% of the best price (w/o shipping) I saw on a search. So if they last 40% of 5 to 7 years, average AGM service life) = 2 to 3 years, then you break even compared to buying new. If they last longer you actually have a saving. If they don't you had a short learning experience.
Why AGM? They generally don't last as long as flooded and they cost more per AH to buy.
|
|
|
Lovetheroad75
Member
|
# Posted: 25 Oct 2016 05:59pm
Reply
I know someone who swears by them and happened across this add; when I saw the price I thought that I would check into it and get some feedback.
|
|
MtnDon
Member
|
# Posted: 27 Oct 2016 02:11pm - Edited by: MtnDon
Reply
Quote from the seller in reply to my inquiry, "The date code is K14, which means that they were manufactured in November of 2014" Already 2 years old. The seller claims they have been serviced, kept charged. I don't know if I would believe that. Who knows how many different hands they have been through since being manufactured?
|
|
Jaust
Member
|
# Posted: 1 Nov 2016 01:43am
Reply
I'm with MtnDon. Serviced and charged or not, 2 yrs is 2 yrs. Batteries will give you maybe 5 yrs at most if well maintained. Early abuse will definitely cut the life of the batteries down.
|
|
offgridjunkie
Member
|
# Posted: 3 Nov 2016 11:27am
Reply
I also use the Trojan 31-AGM's and have had good luck with them. I have just finished two years of use and they are still running strong. Mine are hooked up to panels and a MPPT charge controller and I do not run them down to about 75% DOD even though I could take them to 50%. Having them AGM allows me to keep them inside the house where they are warm and protected and closed to the loads. Never have to check if they have water, and when it gets -10, I don't have to worry about them freezing. All those factors make the price totally worth it. Just my $.02
And yes, battery life depends on abuse/care - no matter what the manufacture says the life of the battery is -
|
|
|
