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-   -   would you buy used AGMs? (http://www.sailnet.com/forums/electrical-systems/134770-would-you-buy-used-agms.html)

rmeador 04-17-2014 02:26 PM

would you buy used AGMs?
 
I need to replace my house bank, which is currently two Group 27s (~110Ah each when new, approximately 0 presently). So I'm looking at golf cart batteries.

I've been presented with an opportunity to buy four GPL-4CT (Lifeline Batteries - Marine & RV Deep Cycle Batteries) used AGM batteries, two years old, that test out well, for $100 each (that's all I know; I don't know what sort of test or how many cycles, etc). These had 220Ah capacity when new, I'm not sure what they're at now. Would you do it? I live aboard, and mostly daysail, but at least once a summer go on a 3-5 day journey usually without shore power. I have a 40A charger and a 65A (?) alternator. Does this sound like an OK idea? I'm probably also going to sell my boat within 2 years (thought it was going to be this year, but likely not...), so I'm looking to not spend a ton of money.

The recommendation from the local battery dealer was Deka GC25s, new, for $170/ea. These have 235Ah capacity, so I only need two to replace my current bank, but I'd really like more capacity... I also really don't want to spend as much as four would cost, so all told if I went with this option I'd probably only buy two of them.

Cost and capacity both seem to be telling me to buy the AGMs, but if they don't last out at least two years, then it will have been a waste of money. What do you think?

TakeFive 04-17-2014 03:35 PM

Re: would you buy used AGMs?
 
I have no direct experience with marine AGM (I do have them on my Prius accessory battiries), so take my advice with a huge grain of salt (preferably Lead Sulfate lol): I've read that AGMs require a more sophisticated charger system, so you should factor that into your overall cost if your charger does not meet AGM requirements. As for what those requirements are, you will need to research it or wait for more expertise here.

miatapaul 04-17-2014 04:16 PM

Re: would you buy used AGMs?
 
Seems that AGMs are easier to ruin with bad use practices so I would be very cautious. If I personally knew the past owner and there habits I might. But $100 seems steep for used, given you don't know the history. Is there any warranty. (either original OE or from seller?) Why is the person getting rid of them?

I would look at Sam's Club golf cart batteries. I believe that is what Mainesail recommends and are around $84 to $112 each.

Maine Sail 04-17-2014 04:17 PM

Re: would you buy used AGMs?
 
Quote:

Originally Posted by rmeador (Post 1747770)
I need to replace my house bank, which is currently two Group 27s (~110Ah each when new, approximately 0 presently). So I'm looking at golf cart batteries.

I've been presented with an opportunity to buy four GPL-4CT (Lifeline Batteries - Marine & RV Deep Cycle Batteries) used AGM batteries, two years old, that test out well, for $100 each (that's all I know; I don't know what sort of test or how many cycles, etc). These had 220Ah capacity when new, I'm not sure what they're at now. Would you do it? I live aboard, and mostly daysail, but at least once a summer go on a 3-5 day journey usually without shore power. I have a 40A charger and a 65A (?) alternator. Does this sound like an OK idea? I'm probably also going to sell my boat within 2 years (thought it was going to be this year, but likely not...), so I'm looking to not spend a ton of money.

The recommendation from the local battery dealer was Deka GC25s, new, for $170/ea. These have 235Ah capacity, so I only need two to replace my current bank, but I'd really like more capacity... I also really don't want to spend as much as four would cost, so all told if I went with this option I'd probably only buy two of them.


Cost and capacity both seem to be telling me to buy the AGMs, but if they don't last out at least two years, then it will have been a waste of money. What do you think?

The only way to know "test out well" with Lifeline AGM's is to do a controlled 20 hour capacity test. Seeing as Lifelines can EASILY be toasted in two years, I would not buy used AGM's that had not had a controlled 20 hour capacity test. Even the Midtronics instruments do not correlate well to "capacity" on Lifeline's. Sure they can easily spot a bad battery or differences between batteries but a 10-20% loss in capacity, not as well...

With Lifelines, I capacity test them....

As an example I just last month capacity tested and conditioned the bank of four Lifline's for my brothers boat (same batteries 4CT's). Under a controlled 20 hour test they are coming in at just about 88% of rated capacity. Using the Midtronics they still test as basically new yet really have lost 12% of their capacity or about 26Ah's.

How much height do you have? I have a set of brand new Full River DC335 AGM 6V's that are 335Ah? Customer changed his mind.... These are the same foot print as a Trojan J305 series, or in between a T105 and an L16... They are a heck of a deal for someone who can fit them...

If used batteries are free or nearly free, go for it, but if they want more than $40.00 each I'd pass it up without a way to do a capacity test..

BTW the Deka DC25 is a flooded battery not AGM. It's smaller sibling the GC15/230Ah can be bought at Sam's Club under the Duracell EGC2 label for about $109.00....

This price was a few years ago.. This is a Deka GC15 with a Duracell sticker...
http://www.pbase.com/mainecruising/image/144571848.jpg


The best value in the Northeast is Deka/Duracell at Sam's Club. The Seabrook store would also have no tax. That said the Deka AGM is not the same quality battery as a Lifeline or an Odyssey AGM but they make a decent reserve or starting battery and if not cycled too hard can even make a decent house battery.

rmeador 04-17-2014 04:35 PM

Re: would you buy used AGMs?
 
Thank you all for the info. I'm not married to the idea of an AGM, and in fact would prefer a flooded or gel battery, but $100/battery seemed like it might be too good to pass up. If I could get new flooded cell batteries for around the same price, I'd go that route! My charger is a Xantrex Freedom HF 1800, which has an AGM mode. The previous owner is getting rid of them because he's upgrading to a bank of 8 L16s.

The area I can dedicate to batteries measures about 20" x 26" x 13" (height), though I can get a little taller in part of it. That's really close to the size of those batteries, Maine Sail... I wonder if I could squeeze two of them in.

The GC15 is only 5Ah less than the GC25? That seems like a tiny capacity loss for such a huge difference in price. I might have to get myself a Sam's Club membership... any idea if Costco carries similar ones? I already have an in there :)

Alex W 04-17-2014 04:43 PM

Re: would you buy used AGMs?
 
I switched to AGMs due to the limited locations for batteries in my boat and the helpful nature of being able to lay AGMs on their side.

Since AGMs are so picky about charging I'd hestitate from buying used ones unless I knew the seller and how they had been cared for.

When I bought my AGM batteries I also added a good multi-stage alternator regulator (about $200, alternator modification, and a fair amount of wiring work) and switched my shore power charger to the AGM setting.

Maine Sail 04-17-2014 04:48 PM

Re: would you buy used AGMs?
 
Quote:

Originally Posted by rmeador (Post 1748074)
Thank you all for the info. I'm not married to the idea of an AGM, and in fact would prefer a flooded or gel battery, but $100/battery seemed like it might be too good to pass up. If I could get new flooded cell batteries for around the same price, I'd go that route! My charger is a Xantrex Freedom HF 1800, which has an AGM mode. The previous owner is getting rid of them because he's upgrading to a bank of 8 L16s.

The area I can dedicate to batteries measures about 20" x 26" x 13" (height), though I can get a little taller in part of it. That's really close to the size of those batteries, Maine Sail... I wonder if I could squeeze two of them in.

The GC15 is only 5Ah less than the GC25? That seems like a tiny capacity loss for such a huge difference in price. I might have to get myself a Sam's Club membership... any idea if Costco carries similar ones? I already have an in there :)

Just show them your Costco membership, tell them you want to evaluate the club (not happy with Costco etc., and ask for a one day trial pass.....

Costco generally sells Johnson Controlls (JCI) batteries which are not quite the quality of the Deka/East Penn product.

btrayfors 04-17-2014 05:24 PM

Re: would you buy used AGMs?
 
After having used T-105 golf carts for more than 20 years, last year in August I replaced all my house batteries with Crown industrial golf-cart batteries. They are rated at 235AH each. I also replaced my Group 31 starting battery, again using Crown. Total cost for six golf carts and one group 31 was $752, including 6% sales tax (at Stevens Battery Warehouse in Annapolis).

Crown batteries are made in the US (OH, I believe) and are of excellent quality.

So far so good. Will be doing periodic testing of these as the season progresses.

Bill

FWIW, Deka (East Penn) and all its brands have been having some problems of late. I wouldn't buy them right now. For example, about 12 AGM batteries in the local West Marine store -- of different sizes, from little ones to big ones -- ALL had resting voltages FAR BELOW what you would expect for batteries dated 1-3 months previous. Furthermore, they would not take a charge properly. Have no idea what the problem is/was, but it's clear there WAS a problem, as others have reported.

B.

Don0190 04-17-2014 07:50 PM

Re: would you buy used AGMs?
 
Quote:

Originally Posted by rmeador (Post 1748074)
='m not married to the idea of an AGM, and in fact would prefer a flooded or gel battery,

I don't really understand this line of thinking. :confused:

AGMs are bad but gel are good and same as FLA?

sck5 04-17-2014 09:17 PM

Re: would you buy used AGMs?
 
No


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