House Battery Question

[rspickel]

I have a battery question relative to my house batteries that need to be replaced.  I currently have 2 12v Lead Acid batteries.  It is difficult to service them because of how they are situated in my coach so I'm thinking about changing.  I think I read somewhere that changing to Lithium batteries could be a problem and I'm not really wanting to spend that much money.  Are there issues with moving to AGM Batteries?  Are there any issues with moving to a single 200 Ah AGM battery rather than purchasing 2 100Ah batteries.  I'm pretty sure that I know the answers to these questions but want to be sure before spending the money.

[rayin]

Welcome to the FMCA discussion forums!

 

AGM batteries are still lead-acid batteries in a different form. Your inverter built-in charger will have an AGM selection which uses the ideal  charging rate for them.

A Renogy 200A AGM battery is $380, a Renogy 200A LifePo battery is $461.

For the $81 price difference you get true 200A of usable power(AGM batteries should not be depleted below 50% for best battery life) and about twice the cycles of use from the LifePo battery. The downside is, if your MH's charger does not support charging lithium batteries, it should be replaced. Also,   you must install a DC to DC charger to prevent burning up the drive engine's alternator. when driving.

Edited February 29 by rayin

[five]

I replaced eight 6 volt AGMs for three 12v AGMs.  The 12 volts are a lot lighter also, so I got rid of lots of excess weight.

[wildebill308]

But how do they compare in storage capacity?

Bill

[five]

Doing fine.  We don't dry camp, so they do fine when on the road.

[superbus]

I recently went through this exercise of deciding which type of batteries to replace my poorly maintained flooded lead acids (that one was on me).  At least for my configuration, price doubled for each move "up" from flooded lead acid, AGM, and finally to lithium (even if looking at halving the number of batteries).  In the end, I decided on AGMs as I did not need to change any part of the inverter/charger system, they don't require nearly as much maintenance as FLA, the added vibration resistance, and the fact there is a big diesel generator in the front of the coach to keep them charged up.  That last part is a big factor, as it negates a lot of the concerns.

Edited March 2 by superbus

[five]

Good move, the AGMs are great.  I would not get Lithiums until they come way way down, and I don't have to figure out how to change my charging system to use them.  It seems I recall where they also have a problem if it is real cold or real hot....don't remember.

Edited March 2 by five

[RRR]

If you mean poorly maintained as not keeping the cells refreshed with water add a battery watering system. Simple to use.  https://www.flow-rite.com/product/qwik-fill-on-board-battery-watering-system/ also on Amazon and I have seen at local auto part store. Gang them together and you have one fill point, unlike my dealer who couldn't figure that out. There is others out there too.

[rayin]

pspickel, made that one post and has never returned, to read replies or update his status.

[sfroese]

Just a note, although a DC-DC charger is the best option, you don't need one. You can also use a Li-BIM isolator. Much easier to wire up. 

Also, the cost of ownership of LiOn over the cost of their lifetime is much lower than the alternatives, and the power vs. weight is much more favorable, as LiOn are roughly half the weight per Ah as lead-acid.

Lots of advantages vs. a few disadvantages. I just upgraded to LiOn while camping last week. Took me about an hour, although it could take longer, depending on what charging and isolating technology you use. 

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