AGM Batteries replacement ?

[woodfox45]

I want to replace my wet cell batteries with AGM batteries what should I look for in a battery largest CCA or AH or both ? My current batteries are wet cell 600CCA
and 750MCA they are marine deep cycle I assume that means marine cranking amps . I looked at an AGM with 750CCA/900CA made by DEKA it'a a marine deep cycle also . Also looked at Interstate 34m 800 CCA/ 64AH they are the most expensive and better warranty . I want to replace them this spring and not sure what to look for . Any help out there ?
Thanks Les Grace

[Tn Traveler]

On your house batteries the CCA are not very important. What you want to look for is reserve capacity and discharge rate. I think this link can explain it.

www.dcbattery.com/faq.html

[Steamy1]

May be a good time to consider switching to two 6-volt Lifeline GPL-4CT wired in series, as many of us have done. You may have to modify the battery box as they are taller.

[Steamy1]

You would also need to upgrade to a 3-stage charger for AGM battery. Several links on this.

[Rich Jenkins]

Originally Posted by Steamy1

You would also need to upgrade to a 3-stage charger for AGM battery. Several links on this.

Can you elaborate on why this would be necessary for AGMs?

[Steamy1]

Following are threads to shed more information on this topic to get you started :

http://www.airforums.com/forums/f449...lts-64324.html

http://www.airforums.com/forums/f449...le-109317.html

[Rich Jenkins]

Originally Posted by Steamy1

Following are threads to shed more information on this topic to get you started :

http://www.airforums.com/forums/f449...lts-64324.html

http://www.airforums.com/forums/f449...le-109317.html

Ok, thanks.

Question: Does AS supply a 3 stage charger when a unit comes with AGM batteries?

[Steamy1]

Another one. See post 3.

http://www.airforums.com/forums/f37/...on-151619.html

[Steamy1]

Originally Posted by Llando88

Ok, thanks.

Question: Does AS supply a 3 stage charger when a unit comes with AGM batteries?

No; you would have to purchase it as a separate component to replace your existing charger/converter assuming you have a single stage unit. You could look at the unit and manual to verify what you have . Post it here and members will help with this.

[Rich Jenkins]

Originally Posted by Steamy1

Another one. See post 3.

http://www.airforums.com/forums/f37/...on-151619.html

I don't see post 3 as answering my question. I have AGM batteries on my '16 FC; I was trying to find out if AS installed a multi-stage charger in it.

Thanks anyway. I'll bow out.

[Steamy1]

Sorry; didn't realize you already had AGMs. If they came with your trailer you most likely have a three stage charger/converter. I would suggest looking at the manual.

[woodfox45]

Originally Posted by Steamy1

May be a good time to consider switching to two 6-volt Lifeline GPL-4CT wired in series, as many of us have done. You may have to modify the battery box as they are taller.

I don't have the battery box on the A-frame mine has the 2 battery doors on the front of the trailer and 6 volts won't fit

[Tn Traveler]

Deka AGM batteries are manufactured by East Penn. Deka dealers will sometimes negotiate price. At any rate the price will be better. I got tired of paying the Lifeline price on my boat. I negotiated two 8d Dekas down to $485.00 ea. That's much better than he nearly $800.00 for Lifelines. Sure the Dekas will not last as long, but at about a 40% savings they are a good deal.

For optimal charging on AGMs a 3 stage chargers is best. However, the flooded battery charge voltage is close to the rate of charge of AGMS. For best charging results in the shortest charge time a 3 stage is best.

[Dan and Liz]

Just looked at a lot of ratings/sites/prices/warranties and decided on Trojan 27AGMs. All the sites I saw said no special charger required for them, but needed for gel cell batteries.

[lewster]

Originally Posted by Tn Traveler

Deka AGM batteries are manufactured by East Penn. Deka dealers will sometimes negotiate price. At any rate the price will be better. I got tired of paying the Lifeline price on my boat. I negotiated two 8d Dekas down to $485.00 ea. That's much better than he nearly $800.00 for Lifelines. Sure the Dekas will not last as long, but at about a 40% savings they are a good deal.

For optimal charging on AGMs a 3 stage chargers is best. However, the flooded battery charge voltage is close to the rate of charge of AGMS. For best charging results in the shortest charge time a 3 stage is best.

Actually.......not so much!!!

There are major discrepancies between the bulk/absorb requirements of liquid cells vs. AGM batteries.

For example: Many of the 'better' liquid lead acid cells like Trojan require up to 14.8VDC for a bulk/absorb charge while many AGMs like Lifeline require 14.2-14.4VDC. It may not seem so.....but a differential of 0.4-0.6VDC is HUGE!!!!

Also, 3-stage converters used as battery chargers are a severe compromise for a few reasons:
• no temperatrue compensation to vary the charge voltage as the ambient temperatures change
•*a 'one size fits all' approach to the size of the battery bank. Battery banks of larger capacity require longer absorb charge times than smaller banks
• you have to use the pre-set charge voltage levels that come programmed into the converter, which don't specifically apply to ANY battery bank

......AND......the quickest, BEST (since you mentioned the word) way to charge any type of battery bank (including lithiums) is to use a FULLY PROGRAMMABLE charger like those found on quality inverter/chargers like Magnum and Victron or Victron's dedicated battery charger systems like the Phoenix and Centaur units.

All are fully programmable for voltage settings, input amperage to the batteries, length of the absorb charge and have full temperature compensation.

[Rich Jenkins]

Originally Posted by Tn Traveler

For optimal charging on AGMs a 3 stage chargers is best. However, the flooded battery charge voltage is close to the rate of charge of AGMS. For best charging results in the shortest charge time a 3 stage is best.

Thanks, that's good info.

I apparently have a Parallax 8300 series inverter/converter in my '16 FC, per the Airstream OM.

From what I gather, it is a single stage converter:

"Parallax 8300 series (formerly 7300 series) are single-stage output converters providing a single voltage output of 13.8 VDC to the DC system for load and battery charging."

http://www.bestconverter.com/8300-Series_c_87.html

So far I've been happy with my AGM batteries, as well as the Solar charging system.

[Troutboy]

The Parallax will kill your AGMs. Get a new one that is programmable, Lewster knows his stuff. He guided me to the new system I am installing as well as many others on these forums.

Getting new AGMs and not a new charger is like changing oil and not replacing filter, or taking a shower and putting on dirty underwear! [emoji12]

[m.hony]

I got 2 Optima Blue Top batteries.
Never replaced the converter/charger, just left the original Parallax (?).
Did consider the upgrade, but what I've got seems to be working.
I might upgrade in the future if I decide I need to.
1 year in so far so good.

[Troutboy]

I also think it depends on the type of camping you do, if you do mainly hookup with utilities, you will not notice the issue as much. If you do more boondocking it will show more. Being plugged in hides the issue from what I have read. I'm not an expert, but have researched much. Also, I may have stayed at a holiday inn express last week[emoji6]

[MelGoddard]

Originally Posted by Tn Traveler

On your house batteries the CCA are not very important. What you want to look for is reserve capacity and discharge rate. I think this link can explain it.

www.dcbattery.com/faq.html

Very useful table for re view.
Thanks