Additional Battery

[Saurd]

Looking for the most effective way to increase the Amp hour capacity of 12v power while disconnected from shore power or truck. My rig is a 2022 30RLS, it currently has a single deep cycle marine lead acid battery, estimating 75-90 amp hours. Initial thought is to ass an additional battery but have the following questions would like to confirm -

• Is the stock battery box strong enough to handle the weight of an additional lead acid battery, dimensionally there appears to be enough room for the another DC 27 size battery
• The current battery is dated 2/23, it only has been drained a couple times, mostly has lived connected to shore power, the truck and has solar to keep it charged. Can I get by with just adding without compromising the new battery to much? Or do I need to buy 2 new ones going forward?

Not ready to jump into investing in the lithium option just yet, just looking for a bit more capacity to get us through the night and the next morning prior to the solar charging the battery(ies). With just using strictly the battery 2-5 nights per season on travel stops just need a little additional time on the battery life.

Looking to learn what others have done and how.

Thanks.

 

[Jim Beletti]

@Saurd - is your battery box the type that is sunk into the floor or is it mounted on surface of the floor? I ask as I'm not certain if the ones that fit into a hole in the floor will support 2 batteries or not. My guess is that it will.

I know that you're not ready for a Lithium upgrade just yet but let me just add...

- The usable Ah of FLA chemistry is about 50% of its rated capacity
- The usable Ah of LiFeP04 is generally, 100% of its rate capacity
- The price of lithium batteries has really come down in the last few years
- You could repurpose your deep cycle FLA battery and replace it with a single LiFePO4 battery and double your usable Ah
- Running a lithium battery flat will not nick into its usable life like FLA does

For less than $300, you can purchase a 100 Ah LiFePO4 battery - link

 

[Oregon_Camper]

Sorry, but I think adding another AGM/FLD battey is just tossing money away. As Jim said above, Lithium batteries are much cheaper now and provide you SOO much more amp hours. Battle Born is still very expensive, but others are much cheaper in the 100 amp hour range, plus they will be about 1/3 the weight.

 

[Saurd]

thanks JIm,
Note sure if you would know or not what is needed from a charging stand point to charge the lithium, believe I was told the rig has what is needed both on the solar and shore power, but would need to know what to verify. Would this battery charge from the truck or not?

Other question I have is I am in Iowa and what affect the cold would have on the lithium battery.

Thanks again for the info.

 

[Jim Beletti]

@Saurd - the converter in your coach should be switchable to Lithium. If your converter is integrated into your AC/DC panel, there will be a tiny switch in there that can be switched to Li.

As for your solar, if you have factory solar and if the solar charge controller is Renogy or Rich Solar, you should be able to reconfigure it for a Lithium charge profile as well.

 

[7ACMike]

Just my 2 cents worth. I live in Iowa also and did the numbers on our 29RL that had 2 deep cycle batteries coming to us. Switched to 2 lithium 100 amp heated Power Queen (excellent reviews) for about $600 total and it works well without the sun for 3-4 days and with the sun/solar seems to be pretty indefinite. Mike

 

[JWalker]

We have a 22 30RLS also.
We did add a second group 27 battery. I did not trust the Alliance plastic battery box to hold the weight, so I reinforced it with a cage to support the box.
The two group 27s will not fit completely down in the battery box. As it tapers inward slightly. But I put a 2 x 8 in the bottom of the box and that lifted the batteries enough to fit perfect.

 

[7ACMike]

Looks very nice! I covered my hole with a new box and used group 31 rather than trust the plastic box as well. Mike

 

[Saurd]

Thank you all for the input, just what I was looking for. I tend to get 'paralysis by analysis' and having these ideas helps.

How long does the 2 group 27 batteries get you? and what brand and amphr are they.