Flooded batteries or agm?

[doorguy]

Looking for some electrical advice from the more knowledgeable than me.

I have 4 ea. 6V flooded house batteries and 2 ea. flooded start batteries. My inverter has a switch setting for AGM if I go that route.

I would like to know if I replace the house batts with AGM, do I need to replace the start batts with AGM also?

[Ray,IN]

No. I've had AGM start batteries since 2018 and had 3 FLA 12V house batteries until this year, when i replaced them with Renogy AGM 12V, 100A batteries. To me, the specs read like AGM batteries use a slightly lower charging voltage than FLA, I tired of continually monitoring water level.
It's easy to look up battery specs on mfgrs. websites if you want specifics.

[dssl]

The inverter charger is for charging the house batteries, not the chassis batteries, so you can go to AGM on just the house batteries.

An AGM is an easy swap. They cost quite a bit more then flooded. The main advantage is they don't require you to top them off periodically with distilled water. If you add a battery watering system then toppling them off is very easy.

LIFEPO4 is another option, which has lots of advantages and the cost difference between lithium and AGM isn't near as big as it once was, although lithium can end up being a bit of a project vs an easy swap. If you do much boondocking then you should definitely look into lithium.

[shootist]

I only see an advantage in agm’s if you let your coach sit a lot with the batteries disconnected. They can handle a year without completely discharging. Adding water and cleaning the compartment with baking soda aren’t a big deal to me, and I don’t want to baby my batteries with the 50% discharge routine because I paid so much for them. If you can put a manual switch on your chassis combiner relay ( very simple with most systems) charging your chassis batteries every few weeks when sitting on an agm profile should not hurt them.

[Ray,IN]

Originally Posted by dssl

The inverter charger is for charging the house batteries, not the chassis batteries, so you can go to AGM on just the house batteries.

An AGM is an easy swap. They cost quite a bit more then flooded..

AGM true deep-cycle batteries are not all that expensive today. This is IMO the best AGM true deep-cycle battery available @ $189. (That includes shipping)


missed the Renogy battery sale in January by 1 day, they were on sale for $99 es.so I thought, tomorrow I'll buy 3 for the MH.

[Winemaker2]

Originally Posted by Ray,IN

AGM true deep-cycle batteries are not all that expensive today. This is IMO the best AGM true deep-cycle battery available @ $189. (That includes shipping)


missed the Renogy battery sale in January by 1 day, they were on sale for $99 es.so I thought, tomorrow I'll buy 3 for the MH.

I may start a disagreement but would avoid Renology. Here is a link that includes a post by Mainsail that does not speak very highly (an understatement) about Renology. He is referencing Li in this thread but the tone doesn't leave me with warm feelings for anything they produce.
https://www.cruisersforum.com/forums...d.php?t=273428
Mainsail aka Rod Collins is a very well respected resource and a guru in the marine electrical / electronic area. He holds certifications from ABYC American Boat & Yacht Council
His very informative website...
https://marinehowto.com/

[dssl]

Originally Posted by Ray,IN

AGM true deep-cycle batteries are not all that expensive today. This is IMO the best AGM true deep-cycle battery available @ $189. (That includes shipping)


missed the Renogy battery sale in January by 1 day, they were on sale for $99 es.so I thought, tomorrow I'll buy 3 for the MH.

As far as relative cost of AGM vs LIFEPO4.

4 x 189 is 756.

A Chins 100ah battery is $319 each. The way they works if you never go bellow 50% on the AGM then 2 would be equivalent, so battery wise the lifepo4 would be cheaper. If you like going bellow 50% then 3 would be a closer match by capacity. Which would be $957 a bit more then 756, but will likely last much longer and can charge more quickly.

With LIFEPO4 you will likely need to spend more on other stuff like new wires, a DC to DC charger or LBIM, a battery monitor, and a different charger if your charger doesn't support lifepo4. Also you can'tcharge LIFEPO4 when they are bellow freezing. So again it's more of a project then a direct swap. But after moving to LIFEPO4 life is good

[Ray,IN]

Winemaker2, I do not have any Renology batteries, i have Renogy batteries, and they are well respected in the solar energy field for storage batteries.



dssi, I do not pay attention to anyone who makes their living writing blogs expressing their opinions.
I have 3 batteries which makes your numbers incorrect. I'm not going to buy LIPo batteries, too many problems. Battle Born batteries are currently having problems and they supposedly are the best available.
I don't care about 10 years of battery life since I'm 80 and my future driving years are very limited.

[Winemaker2]

Originally Posted by Ray,IN

Winemaker2, I do not have any Renology batteries, i have Renogy batteries, and they are well respected in the solar energy field for storage batteries.



dssi, I do not pay attention to anyone who makes their living writing blogs expressing their opinions.
I have 3 batteries which makes your numbers incorrect. I'm not going to buy LIPo batteries, too many problems. Battle Born batteries are currently having problems and they supposedly are the best available.
I don't care about 10 years of battery life since I'm 80 and my future driving years are very limited.

I do not and did not claim any experience w renology.
I do however put a lot of faith in Mainsail, Rod Collins as he posts very technology complete articles and is not in the business of trashing anyone.
He backs up any / all recommendations with facts, test data or significant first hand experience. Others experience may be different and that's OK I only strive to present factual articles I find valuable.

[dssl]

[QUOTE=Ray,IN;6456984]Winemaker2, I do not have any Renology batteries, i have Renogy batteries, and they are well respected in the solar energy field for storage batteries.



dssi, I do not pay attention to anyone who makes their living writing blogs expressing their opinions.
I have 3 batteries which makes your numbers incorrect. I'm not going to buy LIPo batteries, too many problems. Battle Born batteries are currently having problems and they supposedly are the best available.
I don't care about 10 years of battery life since I'm 80 and my future driving years are very limited.[/QUOTE


I'm amused and flattered that you think I make a living by blogging. I don't even blog.

3 batteries implies you have 12v batteries, I assumed you had pairs of 6v like most folks since that gets you better value.

I don't care what you get, I was only trying to offer helpful information Good luck.

[dssl]

Originally Posted by Ray,IN

Winemaker2, I do not have any Renology batteries, i have Renogy batteries, and they are well respected in the solar energy field for storage batteries.



dssi, I do not pay attention to anyone who makes their living writing blogs expressing their opinions.
I have 3 batteries which makes your numbers incorrect.

In the initial post it says

"I have 4 ea. 6V flooded house batteries"

This makes your post even more odd. At any rate definitely do what you thinks makes sense for you. There is definitely no one size fits all solution. .

[astrnmrtom]

Originally Posted by doorguy

Looking for some electrical advice from the more knowledgeable than me.

I have 4 ea. 6V flooded house batteries and 2 ea. flooded start batteries. My inverter has a switch setting for AGM if I go that route.

I would like to know if I replace the house batts with AGM, do I need to replace the start batts with AGM also?

The simple answer is No, you don't need to change your chassis batterie if you switch your house batteries to AGM.

[doorguy]

If want to thank each of you that contributed to my post. I didn't think it through to realize the house batteries are charged thru the inverter and the chassis, the alternator. I DO appreciate the many inputs.
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