AGM 220AH vs 300AH

[Abj1]

Having 500w of solar being installed and need to determine best route for Lifeline AGM battery bank.

On the fence on battery bank size between 220AH or 300ah. Folks out there have real life experience and if the extra cost(and tongue weight) is justified for bigger 300AH battery bank??

Thanks!

[lsbrodsky]

You really need to assess your needs; each of us uses our trailer our own way. Remember that you can only use half of that capacity. How long do you want to be away from a charger and what do you intend to run? You need to add up the amps of the things you will run and then multiply each by the number of hours it will run..
Some people think that more is always better, but not if you will stay plugged in and never use it. We have 150 amp-hours of usable capacity, with solar, and found that even with 4 days in the shade we were never below 70% of that. That would mean a 300 ah bank for you. But again for a night or two you shouldn't need that much.
If you intend to run a lot of stuff off your inverter between charges, then more is probably better.
Larry

[KJRitchie]

I had two Lifeline 6v 220ah batteries install last winter as part of my queen to twin bed remodel with 200w of roof solar. I also have a Zamp 200 portable panel (with it's built in controller removed) I can plug into the system.

We just go back from Yellowstone and spent 7 days of dry camping at Grant Village. The batteries and solar performed well. Installed with the batteries and solar was the Blue Sky IPN Pro monitor. Using that as a guide the lowest the batteries got was 86% overnight. It snowed at the campground from one afternoon until the next morning, we ran the furnace to take the chill off in conjunction with a Little Buddy heater with lights, phone charging. The remaining part of the day was cloudy but between the roof and portable they must have been able to get some solar because when we returned the battery was still at 86% so it held steady throughout the day when we returned from the days putting. I ran the Honda 2000 about three hours to get it back to 100%. The last 10% of a battery charge takes longer. Our charger is a Magnum 1012 1000w inverter/charger. The other days it was partly cloudy with sun and the solar charged up the battery every day while we were out on day trips.

If your power needs are more than ours than 300ah is preferable but that means more solar is need to charge larger battery banks. Despite our batteries located inside under the street twin there is no room to install more capacity unless I replaced them with the 6v 6ct model 300ah. The are 90lbs vs 66lbs for the 4ct which would be another 48lbs of weight. 180lbs on your tongue vs 132lbs and the 6cts are 13" tall vs 10" for the 4CT. I guess its no worse than installing a heavy ProPride or Hensley hitch head. You'll have to modify the battery compartment box for the lid to clear. You may have to make adjustments to your WD hitch for the added weight.

I'm hoping when it comes time to replace my 4CTs I can use Lithiums like the 100ah Battleborns. I'm hoping these drop in Lithiums will be more affordable due to more competition. The useable ah for them is 80 or 160 total vs 110ah for the 4CT or 150 for the 6CT and they are much lighter.

Kelvin

[dkottum]

We found that two Lifeline GPL-31XT at 125 AH each (these are 12 volt batteries so 250 AH total) will fit in our FC 25 battery box. Plenty of usable power for our needs.

I drilled out the rivets holding the battery box lid, trimmed away the metal lip the lid is mounted on with a Sawzall. Then remounted the battery box lid hinge with rivets on the side metal lips.

Its a tight fit but they will drop in. You will need to scrap the two Airstream-furnished parallel battery cables connecting the two batteries and replace with much larger cables, short as possible. The idea is to have as little electrical resistance paralleling the two batteries as possible so they "think" they are one battery.

[Abj1]

Originally Posted by KJRitchie

I had two Lifeline 6v 220ah batteries install last winter as part of my queen to twin bed remodel with 200w of roof solar. I also have a Zamp 200 portable panel (with it's built in controller removed) I can plug into the system.

We just go back from Yellowstone and spent 7 days of dry camping at Grant Village. The batteries and solar performed well. Installed with the batteries and solar was the Blue Sky IPN Pro monitor. Using that as a guide the lowest the batteries got was 86% overnight. It snowed at the campground from one afternoon until the next morning, we ran the furnace to take the chill off in conjunction with a Little Buddy heater with lights, phone charging. The remaining part of the day was cloudy but between the roof and portable they must have been able to get some solar because when we returned the battery was still at 86% so it held steady throughout the day when we returned from the days putting. I ran the Honda 2000 about three hours to get it back to 100%. The last 10% of a battery charge takes longer. Our charger is a Magnum 1012 1000w inverter/charger. The other days it was partly cloudy with sun and the solar charged up the battery every day while we were out on day trips.

If your power needs are more than ours than 300ah is preferable but that means more solar is need to charge larger battery banks. Despite our batteries located inside under the street twin there is no room to install more capacity unless I replaced them with the 6v 6ct model 300ah. The are 90lbs vs 66lbs for the 4ct which would be another 48lbs of weight. 180lbs on your tongue vs 132lbs and the 6cts are 13" tall vs 10" for the 4CT. I guess its no worse than installing a heavy ProPride or Hensley hitch head. You'll have to modify the battery compartment box for the lid to clear. You may have to make adjustments to your WD hitch for the added weight.

I'm hoping when it comes time to replace my 4CTs I can use Lithiums like the 100ah Battleborns. I'm hoping these drop in Lithiums will be more affordable due to more competition. The useable ah for them is 80 or 160 total vs 110ah for the 4CT or 150 for the 6CT and they are much lighter.

Kelvin

Thanks Kelvin- with these new AGM batteries I was planning for the added tongue weight. I currently have a Pro Ride hitch as well. Should I be factor that into my tongue weight as well? I have not done so.

Thanks.

[lsbrodsky]

ABJ,

I see from your profile that you have a Tundra and a 25FB. Your Tundra probably has a payload at the low end of 1/2 ton trucks, look at the door plate. Your stock trailer with a ProPride is going to eat up most of your payload, add more batteries on the tongue and that will eat up even more. If you have minimal other stuff in the truck and bed, then you will still be OK. But make a guess on the weight of the stuff you are carrying in the truck or stop by some truck scales. In my model year the 25FB had one of the heaviest tongue weights and I was at my payload limit with a tonneau cover, stock batteries, ProPride and the usual junk in the truck bed.

Larry

[Abj1]

Originally Posted by lsbrodsky

ABJ,

I see from your profile that you have a Tundra and a 25FB. Your Tundra probably has a payload at the low end of 1/2 ton trucks, look at the door plate. Your stock trailer with a ProPride is going to eat up most of your payload, add more batteries on the tongue and that will eat up even more. If you have minimal other stuff in the truck and bed, then you will still be OK. But make a guess on the weight of the stuff you are carrying in the truck or stop by some truck scales. In my model year the 25FB had one of the heaviest tongue weights and I was at my payload limit with a tonneau cover, stock batteries, ProPride and the usual junk in the truck bed.

Larry

Thanks for the info Larry.

Yes, I'm near the max on my tongue capacity. For my Tundra its 980LBS. And, based on my calculations I'm currently pushing 900lbs with trailer/pro pride/batteries. Sean from Pro Pride said to account for 150lbs against the tongue weight.

Do you know if the Airstream listed tongue weights are inclusive of the batteries and full propane tanks? I hope they are and assume they would be included in their listed trailer tongue weights.

Based on the above calculations I have concerns with added gear etc... in the bed and I have a Snugtop topper.

I'm confused about what goes against the tongue versus payload. Is anything behind rear axel against the tongue and all else considered payload?

Thanks for the info and insight.

[lsbrodsky]

The tongue weight has to be included in the payload calculation.

Larry

[OrangeCrush]

ABJ,
What Larry said except I will add that I believe there is a small amount of tongue weight re-distributed to the trailer wheel. This video is a good demonstration.

https://www.youtube.com/watch?v=XBZu39pQ8Gg

I went through this in great detail with my F150 and 25FB and based on your capacity rating I would be very concerned about adding tongue weight. The capacity number on your sticker usually account for a full tank of gas and 150lb driver. Everything you add including passengers needs to be accounted for in your vehicle load calculation.

With 500 watts of solar, even if you only get 250 watts usable for 8 hours a day you would be adding around 150 AH back to your batteries so I would think the 220AH would do you fine.

Good luck.

Robert