what brand AGM?

[thumped]

It's time for all new batteries.  I have a glider show hauler.  It has a Cummins N14 with 450HP.  My 9 year old wet batteries have slowly been dyeing over the last 4 years and I'm down to 3 out of 7.  Number 4 bit the bucket this morning and I have combined my house and starting batteries.

I want to go with group 31 AGM, but do not know what brand I want to go with.  I want to buy all the same batteries, not different for the house and the starting.

I need 3 or 4 for the starting set and 3 for the house.  I have a DC SunDanzer fridge freezer, DC air conditioner, and a small inverter.  I have dual 3 bank (30 amp) AGM capable chargers.  I also have a 10 HP air cooled diesel with a 160 amp alternator for back up.

I have been looking at Interstate and yellow top Optima, but what other brands should I look at?
What would you buy if you were replacing them all?

 

[Roy M]

I don't believe there are many different manufacturers, they will rebadge for whoever wants to pay the price. Just stay away from offshore brands. The house and starting batteries are not the same. The chassis units will have a higher cold cranking amp rating CCA for maximum performance when starting but won't last running the air conditioning. Deep cycle house batteries won't have the high end punch but can be discharged more before needing a top up.

 

[judway]

I got my pair on sale at Sam's Club. I don't remember the price but it was good.

 

[Larry N.]

Are AGMs good for chassis batteries? If so that's new to me. And I'm sure you already know this, but combining the two sets of batteries eliminates one set of redundancy -- there might be other problems too, but I'm not sure of that.

 

[judway]

Google it,

Duracell AGM Deep Cycle Marine and RV Battery - Group Size 31
by Duracell|Item 347736|
Average rating:4.2909out of5stars, based on55reviews(55)
Ideal for marine applications
Designed to last through long discharges
12V AGM sealed valve
Non-spillable
CURRENT PRICE: $179.74

 

[thumped]

Not all AGM's are good for starting.  A lot of times they will say marine battery, but you need to read all the information to be sure.

I keep the starting and the house batteries separated.  I do have a battery isolator for charging the house battery when driving.  I also have a 175 amp disconnected switch between the 2 groups for when I need to transfer power.  Right now I have all the good batteries connected into a single bank due to only having 3 semi good.

Thanks for the info on the Duracell.  I found a place that has 7 of them for $180.99 each with all the same date that there setting them aside for me.  I'm picking up 4 after work Tuesday and 3 after work Wednesday.  The local places that had them cheaper had old batteries and they were not able to date match on 7.

I like to have matching batteries for house and starting.  I feel in the long run it's easier on the alternator(s) and your able to move to them around latter down the road if needed.

Thanks judway.  I had over googled the other battery things so it messed up the results when looking today.

 

[judway]

Sounds like you have a good plan and got a good price. I really use DuckDuckGo instead of Google but told you a way that works.

 

[thumped]

That's why I asked.

Google tracks my searches and a lot of time it's nice as it uses your past searches to narrow down what your looking for.  I also forget to open a private window when I'm unable to find stuff.
Thanks

 

[Gary RV_Wizard]

The premiere brands of AGM 12v's are Lifeline (from Concorde), Trojan, and Rolls. Whether they are worth the higher price vs the more plebeian brands is a more difficult question.  This is a well-understood technology and AGMs from Johnson Controls, US Battery, Exide and East Penn are all good quality and sold under a variety of brand labels. I'd be inclined to buy on a cost per AH basis.

 

[Matt_C]

<SNIP>
I want to go with group 31 AGM, but do not know what brand I want to go with.  I want to buy all the same batteries, not different for the house and the starting.
<SNIP>

Thumper,

Having matching batteries for main engine and hotel may be fun, but it makes no sense at all.  The two services are vastly different. 

I have done a lot of electric upgrades to performance cruisers (read - retired racing sloop) and I have never found a better main engine starting battery than the rolled cell AGM (Optima and Orbital), but for hotel loads, they are losers because the Ampere/Hour capacity for the same case size is usually way less.  For the hotel/house side. I like and have had good success with Lifeline.  They still die like any other Lead/Acid battery, but they can be great while they are alive.

Matt 

 

[Kevin Means]

Three years ago, I replaced our eight Group 31 AGM house batteries with OEM batteries made by East Penn. They are 105 AH batteries and are sold by Napa. Each battery cost $320.00 and I believe they still cost about the same. They've been excellent batteries, but they are pricey compared to some others. When it comes to batteries, however, I believe you get what you pay for.

I would not spend that much on AGM batteries again. The price of lithium batteries has dropped significantly over the past three years, and while they're still more expensive than AGMs, I believe you get more bang for your buck with lithium batteries in the long run. And lithiums are better suited for the type of usage and charging scenarios that boondockers encounter. JMO

Kev

 

[thumped]

I would not spend the money on top of the line batteries and some of those brands are not made for the shaking of being in an RV.  I'm fine spending less and replacing my batteries a every 6 to 8 years.

Matt_C
I know where your going with this, but at the same time I went with a dual purpose battery.  Yes they are not the best starting batteries and not the best deep cycle batteries, but there in the middle.  I do not need true deep cycle batteries with the way I had my RV built.  If I have 300 amp hours (3 house batteries) I'm able to charge once a day with the AC running in 90* temps off a 10 hp motor that sips fuel or I'm able to plugin and pull around 4 amps @ 120 to run a battery charger; yes the batteries will dip at times, but they will top off.  I understand that some RV's and they way people use them would need a lot more power.