Fullriver batteries

[AJMike]

We have 300 watts of flexible solar panels on our roof which seem to be working well but our current batteries (Type 24) are pretty low in the morning (about 12.1 or 12.2 volts) and sometimes don't fully charge during the day, especially if we are under some shade or if it is not summer. I have been thinking that higher capacity might be better. Of course if our current batteries won't fully charge given the sunlight, neither will higher capacity batteries but I should get more time before I need to run the generator to charge them.

When I called around to the local solar shop the man mentioned some batteries that I have never heard of (Fullriver) and told me that they were 115AH rated each and would fit into our battery compartment (16" wide x 12" high x 12" deep). The idea of replacing 120 AH total batteries with 230AH AGM batteries sounds pretty good but since I have never heard of these batteries and since their rating seems to be almost too good to believe I thought I would ask.

Has anyone ever heard of Fullriver? If so, are they worth buying? Our Camp controller has a setting for AGM so that should not be a problem but I don't want to buy batteries that are not worth the cost.

[Winterbagoal]

Never heard of them, but they have offices in US, Europe, and Asia. Perhaps a clue?
If you upgrade to AGMs or lithiums, they typically have lower internal resistance, and will recharge faster than the GR24 regular maintenance free FLAs.
I would consider going in that direction, as I also have 300W up top and 2 100Ah lithium batteries, and so far they all seem to work well together.

[AJMike]

Originally Posted by Winterbagoal

I would consider going in that direction, as I also have 300W up top and 2 100Ah lithium batteries, and so far they all seem to work well together.

I did not seriously consider Lithium because I understood that they needed to be charged to a higher voltage and that my current alternator would not supply the 14+ volts that they needed to get fully charged. Since you have Lithium what did you do about that? Or is my understanding wrong?

[Winterbagoal]

Do you do a lot of driving between campsites? I'm probably somewhere in between a destination and touring camper/traveler in the Navion. It's got a 220A output alternator, but I'm told the actual output depends on a lot of other factors. I didn't consider the alternator output to be an issue when I switched to lithium. I have it plugged in the driveway, and between the PD9245 (with added Charge Wizard Pendant) and the Zamp solar (ZS-30A charge controller) and shore power, I'm always charged up. If we're on the road a few hours of driving does the job as well. If I see "FUL" (it's what the Zamp controller display shows at full charge, 13.4V), I'm happy.
You'll get different opinions on these things, which is normal. In my limited experience with motorhome power systems, if it works, don't mess with it. I don't see the point of micro-managing my system, and so I don't. I added the Relion RB100-LT lithiums last October, dropped them in as plug and play, without all the fancy gadgets others recommend, and they seem to charge up fine, and work well for me. No issues, so far.

[creativepart]

Full River batteries are very good. They also are quite a bit higher priced.

As for not choosing LiPo because of alternator charging, you could consider a Victron DC to DC charger. It takes alternator output (or any other 12v power source) and gives you a programmable DC output and smart charger to take over charging your batteries. It's not much over $250 and is a great way to maintain LiPo battery charging from your alternator. Plus it protects your alternator from damage at the same time.

[AJMike]

Originally Posted by Winterbagoal

It's got a 220A output alternator, but I'm told the actual output depends on a lot of other factors. I didn't consider the alternator output to be an issue when I switched to lithium. I have it plugged in the driveway, and between the PD9245 (with added Charge Wizard Pendant) and the Zamp solar (ZS-30A charge controller) and shore power, I'm always charged up. If we're on the road a few hours of driving does the job as well. If I see "FUL" (it's what the Zamp controller display shows at full charge, 13.4V), I'm happy.

I need to first say that I have no actual knowledge about this so anything I write is based on information I have read somewhere. That information may be wrong.

It was not the amp output of the alternator that I was concerned with, it was the voltage. As I understand it the alternator generates about 13.7 or 13.8 volts which is more than enough to charge both wet cell and AGM batteries to full, but not enough to charge Lithium-ion batteries to full. The batteries will not charge above the voltage being applied and if L-I batteries require 14.? volts to fully charge an alternator that produces 13.5 volts can not charge it to its capacity regardless of the amperage. I guess that is why solar panels produce 18 volts to charge a 12 volt battery.

What is a PD9245? I have never heard of it and perhaps it is the reason that your L-I batteries are doing well. Or perhaps everything I thought was correct that I had read about L-I batteries is wrong ...

[AJMike]

Originally Posted by creativepart

Full River batteries are very good. They also are quite a bit higher priced.

Most of the shops around where I live want to replace the Fuse's OEM batteries with Interstate 34M AGMs and they are $300+ dollars for 62AH rated batteries. The Fullriver AGMS are supposed to bar 115AH and cost about $330 from the local Solar shop, + $50 for installation. That actually sounds like a bargain to me. Perhaps these people are just not gouging as much as some others?

Originally Posted by creativepart

As for not choosing LiPo because of alternator charging, you could consider a Victron DC to DC charger. It takes alternator output (or any other 12v power source) and gives you a programmable DC output and smart charger to take over charging your batteries. It's not much over $250 and is a great way to maintain LiPo battery charging from your alternator. Plus it protects your alternator from damage at the same time.

So this does what? Modify the output from the alternator so that it produces enough voltage to fully charge the Lithium-ion batteries?

The same Solar shop that is offering the Fullriver AGM batteries told me that they no longer sell Lithium-ion batteries for RVs because they still have serious issues - early failures, fires and an inability to maintain their rated voltage. I am not suggesting that what I am told is correct - I know so little about this subject that I can't immediately vet anything a sales guy tells me and so I tend to be very suspicious. Still, if they were selling L-I batteries and stopped doing so I would assume there was some reason.

Have you had any issues with L-I batteries? And what are good brands? I read a lot about Battle Born but know nothing about them or about other brands that might be just as good but not have a recognizable name.

[Winterbagoal]

Originally Posted by AJMike

I need to first say that I have no actual knowledge about this so anything I write is based on information I have read somewhere. That information may be wrong.

I have some knowledge and have consulted Battle Born and Relion technical support during the research phase of my lithium upgrade. However, a little knowledge can be a dangerous thing, or so they say.

Originally Posted by AJMike

It was not the amp output of the alternator that I was concerned with, it was the voltage.

I have a Scangauge II with a VLT gauge that tells me my alternator's output is regularly over 14V when driving. It puts out whatever the rest of the systems can handle, in that voltage range.

Originally Posted by AJMike

As I understand it the alternator generates about 13.7 or 13.8 volts which is more than enough to charge both wet cell and AGM batteries to full, but not enough to charge Lithium-ion batteries to full.

See prior response. Any amount of charge will eventually charge lithium batteries to full, but it will take longer. Also note that unless you draw them down to zero (0) state of charge, they don't need to be fully recharged. Partial recharge is fine. It comes down to personal preference. Some people aren't satisfied unless they see some add on fuel gauge gadget tell them that their batteries are full. I'm not one of them.

Originally Posted by AJMike

The batteries will not charge above the voltage being applied and if L-I batteries require 14.? volts to fully charge an alternator that produces 13.5 volts can not charge it to its capacity regardless of the amperage. I guess that is why solar panels produce 18 volts to charge a 12 volt battery.

Again, it's not the voltage that is as important as the current you're feeding them. It's what gets stored in the batteries as potential energy. More amps is better for charging lithium, and the better lithium batteries have built in BMS systems with all sorts of safety features algorithms that protect them from bad stuff happening, like over or under charging.

Originally Posted by AJMike

What is a PD9245? I have never heard of it and perhaps it is the reason that your L-I batteries are doing well. Or perhaps everything I thought was correct that I had read about L-I batteries is wrong ...

It's my factory converter/charger. I added the Charge Wizard Pendant, so I could increase the rate of charge if I want to recharge them faster on generator or shore power, at the touch of a button. You can kick up the charging current to 14.4V for around 2 hours, IIRC, to hit them harder if desired. I do it once in a while just to make sure it still works, if I ever really need to speed up the charging process, like before checkout at the campground.

[Morich]

Batteries are one of those really simple things that actually are quite a lot harder to figure than first look. All batteries are a chemical reaction of various sorts and one thing is common in all charging. The higher the voltage the higher the difference in input and what is stored. So yes, higher voltage does get more flow initially but most alternators on the vehicle will be putting out more than 14 volts when running down the road. Figure day or more to get full charge really done. So how fast each type charges is part of the factor but the way we read the voltage can mess with our mind.
Think of the chemical reaction like adding black paint to white paint as we charge. If we do it for a bit and then take a look at the surface (like voltage check?) we may see lots of black paint and think the whole thing is black but after it settles out and slowly does the chemical reaction, that black is not nearly as black as we might guess. We have to let things settle and then a voltage check is closer to the real story. But that settle time may take several days. How long varies with type, age, temperature, and lots of small things so a voltage check is an easy kinda sorta answer more than true fact of how good the battery is. Better than nothing but not as good as a load test or specific gravity testing.

[Park Super]

We have 300 watts of flexible solar panels on our roof which seem to be working well but our current batteries (Type 24) are pretty low in the morning (about 12.1 or 12.2 volts) and sometimes don't fully charge during the day, especially if we are under some shade or if it is not summer.

Sounds like your system is working as designed. Batteries at 12.1 volts is still at 50%. You can draw them down further. Running the gen to charge batts to 80% and letting the solar top off the charge is your best bet with your system. Works well for us with 270 watts of solar and 150 amp hour capacity. A couple hours of gen time in the morning and evening when cooking and solar all day gets the batts up to where you want them, then batts do not need to be replaced. You are correct that changing to more capacity will take more time to charge. This will require more gen time or you will need to add more solar. If you really need more capacity and you want less charge time you will need to go lithium and all the up grades that go with them.

[AJMike]

Originally Posted by Park Super

Sounds like your system is working as designed. Batteries at 12.1 volts is still at 50%. You can draw them down further.

I thought that 50% was the lowest you were supposed to draw down batteries and if they were lower they might be damaged and lose their ability to recharge. Is that wrong?

Originally Posted by Park Super

A couple hours of gen time in the morning and evening when cooking and solar all day gets the batts up to where you want them, then batts do not need to be replaced.

We dry camp a lot, but often in regular campgrounds, and we usually can not run the generator in the morning due to "quiet hours". Usually we are not allowed to run the generator until about 10 am and by then the sun is up here in Arizona and charging the batteries.

In the Summer there is enough sun directly overhead that we can reach full charge by late afternoon but in the Winter, late Fall and early Spring we are not so fortunate and often we can only get enough solar power to charge the batteries up to perhaps 12.6 volts instead of 12.8.

[creativepart]

Mike, Interstate 34M AGM are dual purpose Marine/RV batteries AKA Starting/Deep cycle. Not at all a good choice for an RV house battery.

Also, the excuse they gave you for not selling lithium batteries is certainly another very big red flag about that shop. Fires, are not an issue with the type of lithium battery used in RVs, never has been. Different chemistry than with electric cars and Boeing Jets.

I’d be very concerned about any “solar shop” that recommended that type of battery for RV house battery use and made those others statements. In fact, I’d run away form that shop.

I have no direct experience with the Full River product, but I’ve seen good reviews. The prices I saw mentioned were higher. Though looking at them now they do seem pretty reasonably priced.

I’m unfamiliar also with the Fuse house battery storage space. If it’s Group 24 sized, how are these shops thinking you can get such larger batteries into that space? I see you posted the storage area size, I haven’t looked to see what fits in that space. It sounds a lot larger than Group 24.

[creativepart]

You’re correct about 50% discharge... but it’s a general rule to extend the life cycle of the battery bank. Going to 40% won’t kill your batteries. Done repeatedly it can shorten their life span. As in getting 3-yrs of service rather than 3.5-yrs out of them, (made up numbers) for example.

Just as important is quickly getting them back to full-charge and generally keeping them at or near full charge. Storing them correctly too.

When we see “generator hours” in campgrounds we usually see 8am to 8pm times.

Keep asking questions, it sounds like you’re on the right path.

We have 400 aH of AGM batteries and 300 watts of solar in our Class A. We try to keep our batteries at or near full charge. When dry camping in cooler weather, where we need to run the propane furnace and our residential fridge we will be at ~ 65% state of charge in the morning. Then we run the generator for an hour or less to make breakfast and let the sun finish charging our batteries during the day.

At night we’ll top them up with running the genset during dinner prep - but run it about 1.5 hrs to make sure we’re at least 98% SOC before bedtime.

Anytime we need the microwave we run the generator because it uses so much of the battery charge to use the inverter for that. But all other loads we leave to the battery and inverter.

I’ve installed a shunt-based battery monitor, so I can see my state of charge in percentages rather than use voltage because that reading is so often unreliable. I recommend anyone dry camping install one as a first step to understanding their RVs electrical use and needs.

[AJMike]

Originally Posted by creativepart

I’m unfamiliar also with the Fuse house battery storage space. If it’s Group 24 sized, how are these shops thinking you can get such larger batteries into that space? I see you posted the storage area size, I haven’t looked to see what fits in that space. It sounds a lot larger than Group 24.

The storage area is exactly large enough to hold 2 Type 24 OEM batteries with just about no room to spare. In fact the batteries that came with the Fuse were so tall that there was no room to get to the top of the batteries to add water and, since the tray does not slide out, maintaining the batteries was next to impossible. I assumed I would replace them when they went bad (which would not take too long here in Arizona when you can't refill the batteries) but we went boondocking in an area that had too many potholes and the rocking and rolling of the RV spilled so much fluid from the batteries that it became necessary to replace them early.

Originally Posted by creativepart

Not at all a good choice for an RV house battery.

Yes. I think I know that now.

When I replaced the OEMs I called around to find good replacement batteries but everywhere I spoke with told me to use the Interstate 34M batteries that I ended up buying. I called Interstate and asked them if these were good RV coach batteries and, of course, they said they were wonderful RV coach batteries. When they gave me the specs in CCA rating instead of AH rating I was deeply suspicious but not a single RV repair shop in the area suggested any other batteries than the Interstate and only the Group 34M, and that included both the RV dealer where I bought the RV and the local RV repair shop that otherwise seems to do very good work.

In the end I did not know enough to see through all of the great comments about these batteries so I went for them. They are not bad and they seem a bit more resilient than the OEM batteries in terms of charging after sizable discharge but I will probably replace them. I just want to do it right this time.

Originally Posted by creativepart

When we see “generator hours” in campgrounds we usually see 8am to 8pm times.

The places we typically stay tell me 10 am to 8 pm and those are the hours that we have had to live with. That usually means that we can't even eat breakfast before we head out and we have to find some place to stop where we can run the generator.

All of the California State Parks that we have stayed at gave us those hours as did some of the Arizona, Texas and New Mexico State Parks. I just assumed it was standard.

Originally Posted by creativepart

At night we’ll top them up with running the genset during dinner prep - but run it about 1.5 hrs to make sure we’re at least 98% SOC before bedtime.

My wife hates the sound of the generator so we don't run it much. The LP generator in the Fuse is noticeably quieter than the gas generator in our last RV but it is still pretty noisy. We have to really need the charge before I run the generator for any length of time.

In the summer, of course, the noise from the generator is not as abusive as the heat from the sun so we have learned to live with it.

Originally Posted by creativepart

I’ve installed a shunt-based battery monitor, so I can see my state of charge in percentages rather than use voltage because that reading is so often unreliable. I recommend anyone dry camping install one as a first step to understanding their RVs electrical use and needs.

I spoke with Battle Born tech support this morning to get some battery information and they suggested the Victron model along with a DC-to-DC charger for the batteries. They also suggested getting a single 100AH battery to replace the 2 AGMs that are currently in the storage area although they also mentioned that since the batteries were very safe I could put them someplace other than the restricted space in the current battery compartment. I do have considerable storage in our Fuse and I could probably put 2 100AH batteries in one of the storage units if I was willing to rewire the battery connections and that is one thing I will consider.

[creativepart]

Sounds like all good info.

One thing to note... your RVs HOUSE batteries are to be deep cycle dedicated for house appliances and inverter. You mentioned on two occassions that you are asking for COACH batteries- those are acutally called Chassis batteries and those are STARTING batteries for the engine in your RV.

If you ask a retail battery shop for COACH batteries you're going to get just that - starting batteries for your RV's motor.

What you need are HOUSE batteries not COACH. Two different things. But I think you've learned that now.

In your earlier posts you said one place suggested two 120 aH Full Rivers - but those would never fit your space. Neither would the two 34M - those are group 34 batteries. You have space for Group 24 batteries. By the way the "M" in 34M is for Marine. When ever you see Marine and CCA - that's not a battery you need for your HOUSE batteries.

A Battery's physical size has a direct bearing on the amount of Amp Hours possible inside that battery case. A Group 24 battery is limited by it's size to no more than 85 Amp Hours. So, you'll see 75 aH and 85 aH rated deep cycle batteries in Group 24. When someone quotes you 100 aH or more... it's for a battery size bigger than Group 24. You may be able to get one in your space - but not two.

Battleborn is offering a Group 31 drop-in 100 aH Lithium battery. So, only one would fit in your space. They don't make Group 24. They do make smaller batteries but they are 50 aH and that wouldn't be an improvement.

Their batteries can be mounted almost anywhere, including indoors because they don't off-gas, and are solid so they can be mounted on their side.

Even though you'd be installing only one Battleborn or other Lithium (LiPo) you'd be getting nearly 100 usable amp hours because you can routinely drop these down to nearly empty over and over without damage. Also, you can draw great amounts of power from them, charge them back up faster and you no longer have the requirement to get them back to 100% right away like you do with Lead Acid.

I think your basic choice is to go with 2-Group 24 85 aH Full River AGMs for 170 aH total and 85 aH usable for about $500 (I found them online for $252 each for two). OR one LiPo (Battleborn) Group 31 100 aH battery with about 90 aH usable for $950. PLUS, the Victron DC-DC charger. About $1200 plus installation of the dc to dc charger unless you can do that yourself.

So, the Battleborn plan is more than twice the cost initially, but they will last at least twice and more likely 3 times as long and give you better service.

I know if my AGMs were dying, I'd pony up the money for LiPo instead or replacing them with more AGMs.

[AJMike]

Originally Posted by creativepart

Sounds like all good info.

One thing to note... your RVs HOUSE batteries are to be deep cycle dedicated for house appliances and inverter. You mentioned on two occassions that you are asking for COACH batteries- those are acutally called Chassis batteries and those are STARTING batteries for the engine in your RV.

My mistake. Thank you for pointing that out. I guess I thought Coach batteries were House batteries. I will have to remember to be more careful when shopping for replacement batteries.

Originally Posted by creativepart

In your earlier posts you said one place suggested two 120 aH Full Rivers - but those would never fit your space. Neither would the two 34M - those are group 34 batteries. You have space for Group 24 batteries. By the way the "M" in 34M is for Marine. When ever you see Marine and CCA - that's not a battery you need for your HOUSE batteries.

The space in my battery compartment is 16" width x 12" height x 12" depth. The Fullriver DC-115-12 batteries are listed as 12.9" depth x 6.8" width x 8.7" height. The only issue would be the depth and since there is hang-over space behind and in front of the current batteries I think they would fit. For what it is worth I currently have 2 Type 34M AGM batteries in that space now and they actually don't even take up all of the room available.

I did not know that the M was for Marine but there is one more thing I have learned. I already knew these were the wrong batteries unless, of course, I try to convert the RV into a house boat?

Originally Posted by creativepart

Their batteries can be mounted almost anywhere, including indoors because they don't off-gas, and are solid so they can be mounted on their side.

Or, according to the Battle Born guy, upside down. He said there is no liquid in them so they could be mounted pretty much in any configuration.

Originally Posted by creativepart

Even though you'd be installing only one Battleborn or other Lithium (LiPo) you'd be getting nearly 100 usable amp hours because you can routinely drop these down to nearly empty over and over without damage. Also, you can draw great amounts of power from them, charge them back up faster and you no longer have the requirement to get them back to 100% right away like you do with Lead Acid.

I think your basic choice is to go with 2-Group 24 85 aH Full River AGMs for 170 aH total and 85 aH usable for about $500 (I found them online for $252 each for two). OR one LiPo (Battleborn) Group 31 100 aH battery with about 90 aH usable for $950. PLUS, the Victron DC-DC charger. About $1200 plus installation of the dc to dc charger unless you can do that yourself.

So, the Battleborn plan is more than twice the cost initially, but they will last at least twice and more likely 3 times as long and give you better service.

I know if my AGMs were dying, I'd pony up the money for LiPo instead or replacing them with more AGMs.

Thanks for the information. As it is the batteries are working OK. I am now sure they are the wrong batteries but they probably are going to continue to be OK for the next short while, although I may replace them just to have it out of my mind and to stop worrying about running out of power.

The only thing I worry about in getting a single battery is that if something goes wrong with it I have no house power while if I get 2 smaller LI batteries I could survive with only one of them working. The cost of getting 2 50AH instead of 1 100AH batteries is about $100 and might be worth that for the peace of mind. I guess it will depend upon the installation cost.

As for doing any of this work myself - anything past using a simple screwdriver and, perhaps, a crescent wrench is probably beyond my mechanical expertise. I knew I should have paid more attention in shop class.

[creativepart]

Originally Posted by AJMike

The space in my battery compartment is 16" width x 12" height x 12" depth. The Fullriver DC-115-12 batteries are listed as 12.9" depth x 6.8" width x 8.7" height. The only issue would be the depth and since there is hang-over space behind and in front of the current batteries I think they would fit. For what it is worth I currently have 2 Type 34M AGM batteries in that space now and they actually don't even take up all of the room available.

If you can fit two DC-115-12 Fullriver batteries then you can fit two Battleborn lithium batteries.

That means you can accommodate ~26" in battery width in a 16" wide battery bank. I guess I've heard of others cutting off the sides of the floor in their battery bank and putting in a new floor to utilize the whole space.

Here's a link to Battery Guy's website. They list 4-deep cycle group 31 AGMs from just under $200 to just over $400.

https://batteryguys.com/collections/...ose_deep-cycle

And here are the Group 31 AGMs that Winnebago puts OEM in their RVs;
https://www.napaonline.com/en/p/NBP9831DT

Most all US Batteries are made by one or two companies and just sold with different names on them. Eastern Penn/Deka makes the most.

VMax sells one with a bit higher amp hour rating of 135 amp hours:
https://www.amazon.com/VMAX-XTR31-13.../dp/B071K538YK

Installing batteries is not a very technical job and is easily handled EXCEPT the weight as each battery is usually 65 or more pounds.

[AJMike]

Originally Posted by creativepart

If you can fit two DC-115-12 Fullriver batteries then you can fit two Battleborn lithium batteries.

That means you can accommodate ~26" in battery width in a 16" wide battery bank. I guess I've heard of others cutting off the sides of the floor in their battery bank and putting in a new floor to utilize the whole space.

Ah. I see the confusion.

The battery compartment in the Fuse stores the batteries with the side usually designated as width being the depth. That is, the battery narrow side faces forward so the battery compartment in the Fuse can accommodate 2 narrow faces, each 8" wide with a depth (ie, width) of 12" + overhang. Given that you are probably right - I can perhaps put 2 100AH batteries in that compartment. Not only that, but the height will actually leave space at the top since the current height of 12" will leave the top of the batteries open.

Originally Posted by creativepart

Here's a link to Battery Guy's website. They list 4-deep cycle group 31 AGMs from just under $200 to just over $400.

https://batteryguys.com/collections/...ose_deep-cycle

And here are the Group 31 AGMs that Winnebago puts OEM in their RVs;
https://www.napaonline.com/en/p/NBP9831DT

Most all US Batteries are made by one or two companies and just sold with different names on them. Eastern Penn/Deka makes the most.

VMax sells one with a bit higher amp hour rating of 135 amp hours:
https://www.amazon.com/VMAX-XTR31-13.../dp/B071K538YK

Installing batteries is not a very technical job and is easily handled EXCEPT the weight as each battery is usually 65 or more pounds.

My mechanical skill does include changing the batteries but I would not attempt to install the battery monitor or the DC-to-DC adapter. That is what I would want done by someone who knew what they were doing. However I am not sure that the shelf, which is hung down from the top, can hold 130+ pounds. I will need to check to see what the original battery weight was.

I will check the links you provided. Thank you.

[Phil G.]

Originally Posted by AJMike

We have 300 watts of flexible solar panels on our roof which seem to be working well but our current batteries (Type 24) are pretty low in the morning (about 12.1 or 12.2 volts) and sometimes don't fully charge during the day, especially if we are under some shade or if it is not summer. I have been thinking that higher capacity might be better. Of course if our current batteries won't fully charge given the sunlight, neither will higher capacity batteries but I should get more time before I need to run the generator to charge them.

When I called around to the local solar shop the man mentioned some batteries that I have never heard of (Fullriver) and told me that they were 115AH rated each and would fit into our battery compartment (16" wide x 12" high x 12" deep). The idea of replacing 120 AH total batteries with 230AH AGM batteries sounds pretty good but since I have never heard of these batteries and since their rating seems to be almost too good to believe I thought I would ask.

Has anyone ever heard of Fullriver? If so, are they worth buying? Our Camp controller has a setting for AGM so that should not be a problem but I don't want to buy batteries that are not worth the cost.

I have had a couple of those Fullriver 12V, Group 31, true deep cycle AGM batteries in our Itasca (Winnebago) Class C motorhome for 3-4 years now. They're rated at 115AH each, so the two of them in parallel provide a total of 230AH.

Two of them fit nicely right under the coach entrance step - which is the stock location for the coach batteries in our Class C - with room to spare.

They have performed very well and are kept charged mainly with the stock 13.8V converter that came built into the motorhome, and the Ford V10's 130 amp alternator.

Those AGM batteries were expensive (~$305 each) ... but were slightly less expensive than the "top of the line" Lifeline AGM batteries that I was thinking about buying. I chose Fullriver batteries over LIfeline batteries because of Fullriver's world-wide reputation in the marine world, and because of their recommended float voltage of 13.5 to 13.8 volts. This made the Fullrivers a perfect match for the the stock converter so that I could leave the converter powered up all the time ... without ruining the Fullriver AGM batteries due to all the time that I have the RV plugged into power during storage at home.

The Lifeline AGM batteries recommended float voltage was 13.2 volts, and when I called Lifeline they stated that constant floating at the stock converter's 13.5 to 13.8 volts would slowly but surely dry out and ruin the Lifeline batteries.

Note that AGM batteries have very low internal resistance, which means that they charge faster than liquid acid batteries - at whatever charging voltage one applies to the AGM batteries. Hence my motorhome's stock converter usually charges my Lifeline batteries fast enough for our camping style. The engine alternator also hits them with over 14 volts for awhile whenever we travel between campsites.

[AJMike]

Originally Posted by Phil G.

I chose Fullriver batteries over LIfeline batteries because of Fullriver's world-wide reputation in the marine world, and because of their recommended float voltage of 13.5 to 13.8 volts. This made the Fullrivers a perfect match for the the stock converter so that I could leave the converter powered up all the time ... without ruining the Fullriver AGM batteries due to all the time that I have the RV plugged into power during storage at home.

Please forgive my ignorance, but what is the "stock converter" you refer to? Is that just part of the standard OEM alternator connection to the house batteries? Or is it something else.

And are these batteries that you can just drop into the RV without having to add any other equipment? $600 is expensive but a lot less than the $1000 for each Lithium 100AH battery, and if it does not require any additional equipment that is another savings.

My alternative is to get a single 100AH Lithium battery + the alternator isolator and then add another battery in a year or two. That would also work but is more expensive and would require that I use the RV with only a single house battery for one or more years and I am not sure I am comfortable with that.