Log In | Register
Skip to main content
Topic: AGM battery AH size under fridge, MB (Read 7 times) previous topic - next topic
0 Members and 3 Guests are viewing this topic.
AGM battery AH size under fridge, MB
Yahoo Message Number: 129591
Hi,
 Has anyone installed two Lifeline GPL-6CT (300 AH) under the refrigerator of a MB, coupled with two Lifeline GPL-4CT (220 AH) in the battery compartment?  This would give me 520AH total (in a perfect world).
 I don't think I want to install the 6CT in the battery compartment because it's a really tight overhead fit and with all the connections to the battery, I don't particularly want the headaches and bruised knuckles.  I like to keep things simple (KISS).

Any thoughts on the subject???

Bob
2000 MB
Re: AGM battery AH size under fridge, MB
Reply #1 –
Yahoo Message Number: 129594
Quote
Hi,
 Has anyone installed two Lifeline GPL-6CT (300 AH) under the refrigerator of a MB, coupled with two Lifeline GPL-4CT (220 AH) in the battery compartment?  This would give me 520AH total (in a perfect world).
 I don't think I want to install the 6CT in the battery compartment because it's a really tight overhead fit and with all the connections to the battery, I don't particularly want the headaches and bruised knuckles.  I like to keep things simple (KISS).

Any thoughts on the subject???
I've heard multiple times not to mix type, age, or size of batteries in a battery bank.  You might want to be conservative and use 4 of the same battery.

Art
Art and Barbara
Settled in Atterdag Village of Solvang
2015-2022 fulltime in a 2016 Tiffin Allegro Bus 37AP
2002-2015 2002 LD MB
Art's blog
Re: AGM battery AH size under fridge, MB
Reply #2 –
Yahoo Message Number: 129596
Quote



Hi,
 Has anyone installed two Lifeline GPL-6CT (300 AH) under the refrigerator of a MB, coupled with two Lifeline GPL-4CT (220 AH) in the battery compartment?  This would give me 520AH total (in a perfect world).
 I don't think I want to install the 6CT in the battery compartment because it's a really tight overhead fit and with all the connections to the battery, I don't particularly want the headaches and bruised knuckles.  I like to keep things simple (KISS).

Any thoughts on the subject???
 I've heard multiple times not to mix type, age, or size of batteries in a battery bank.  You might want to be conservative and use 4 of the same battery.

Art
Thanks for reminding me of that.  My ambitions got the better of me (as usual).  I went back and reread the Lifeline manual and there it was:
 "Always use batteries of the same size and condition in multi-battery installations. When replacing batteries, it is best to replace the entire set of batteries so they remain balanced."

Thanks again, Bob
2000 MB
Re: AGM battery AH size under fridge, MB
Reply #3 –
Yahoo Message Number: 129600
"You might want to be conservative and use 4 of the same battery."
 Make it five. I made this mistake when i upgraded my 2003 midbath with four Concorde group 27 (105 Ah) AGMs--two outside and two inside. I quickly realized that there was room for three batteries under the fridge, and considering that the labor would have cost very little more, I ended up kicking myself for not doing it that way.
 It took another year before I got around to adding that fifth battery (which technically violates the "same age" rule of thumb, but I haven't seen any problems). My advice: if you're going to put more than two AGMs in a midbath, go with five.

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: AGM battery AH size under fridge, MB
Reply #4 –
Yahoo Message Number: 129602
Quote
"You might want to be conservative and use 4 of the same battery."
 Make it five. I made this mistake when i upgraded my 2003 midbath with four Concorde group 27 (105 Ah) AGMs--two outside and two inside. I quickly realized that there was room for three batteries under the fridge, and considering that the labor would have cost very little more, I ended up kicking myself for not doing it that way.
That will work fine as long as the OP changes from 6V batteries to 12V.

Art
Art and Barbara
Settled in Atterdag Village of Solvang
2015-2022 fulltime in a 2016 Tiffin Allegro Bus 37AP
2002-2015 2002 LD MB
Art's blog
Re: AGM battery AH size under fridge, MB
Reply #5 –
Yahoo Message Number: 129603
This is exactly the configuration of Lifeline batteries I had installed by AM Solar when I went for the massive solar upgrade.
 Here's what they put on:  (2) RV-150 + (2) RV-100 (for 500W) and (2) 300 AH + (2) 220 AH (for 520 AH) total.
 Their guidance was not to add the extra batteries down the road, as the age difference would have an affect on how well they charge.

So, FWIW, such a configuration is fine according to AM Solar.

S-

Steve and Carol Crisp, ThistleDewToo-less
Steven & Carol Crisp -- 2000 26.5' Blue Mid-Bath named Thistle Dew Too
Our RV Motto:  "No place to be ... and all day to get there"
2024 Adventure: The Great Eclipse Escapade!  HI(Air),NV,AZ,NM,Mason,TX(Totality!) ...
Re: AGM battery AH size under fridge, MB
Reply #6 –
Yahoo Message Number: 129608
Interesting.  I have always heard that you can't mix panel types either.  Andy?
Re: AGM battery AH size under fridge, MB
Reply #7 –
Yahoo Message Number: 129613
"I have always heard that you can't mix panel types either."
 It's best not to mix panels with differing output voltages (e.g., 36-cell panels with 44-cell panels. Doing so won't damage anything, but you could find your system's output limited by the lower-voltage panels, or so I've read.
 But there's nothing wrong with mixing panels of differing wattages, such as 100W and 150W. This can be useful if you're trying to make the most of real estate on the roof.
 I still, think, however, that it's not a good idea to mix batteries of differing capacities (amp-hour ratings). On this point I respectfully differ with AM Solar. Oh, it's not fatal... but it isn't the best idea, if you want to maximize storage capacity and battery life.

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: AGM battery AH size under fridge, MB
Reply #8 –
Yahoo Message Number: 129620
Quote
"I have always heard that you can't mix panel types either."
 It's best not to mix panels with differing output voltages (e.g., 36-cell panels with 44-cell panels. Doing so won't damage anything, but you could find your system's output limited by the lower-voltage panels, or so I've read.
 But there's nothing wrong with mixing panels of differing wattages, such as 100W and 150W. This can be useful if you're trying to make the most of real estate on the roof.
 I still, think, however, that it's not a good idea to mix batteries of differing capacities (amp-hour ratings). On this point I respectfully differ with AM Solar. Oh, it's not fatal... but it isn't the best idea, if you want to maximize storage capacity and battery life.

Andy Baird http://www.andybaird.com/travels/
THANK YOU ALL for your input,.

Bob
2000 MB
Re: AGM battery AH size under fridge, MB
Reply #9 –
Yahoo Message Number: 129640
I agree with Andy on mixing batteries of differing capacities.  I think what would happen is that due to the lower internal impedance of the larger capacity batteries, they would do more than there fair share of the charging/discharging process.  On the other hand, it may not  be a big deal