OEM battery question

[AJMike]

I have an odd problem.

Some time ago I replaced the OEM batteries with AGMs so I no longer have the original batteries. The battery storage area in our RV (2018 Winnebago Fuse, 23T) is a hanging shelf and because I did not know how much weight the shelf could hold I got small light weight AGMs to replace the originals. The AGMs I got seem to have too small a capacity for our use and thus I may have to replace them again but this time, if I do, I want to get batteries that are large enough to handle what we need, but not so heavy as to put too great a strain on the hanging shelf.

I called Winnebago this morning to find out what batteries were included with the RV when it was new, assuming I could then find out what they weighed, but the tech could only give me specs for the battery, not the original model type, and thus I know that they were 550 CCA 65AH batteries, but NAPA, the battery manufacturer does not seem to currently have any existing batteries that match those specs so I am still out of luck.

If anyone has a 2018 (or close) Winnebago Fuse with OEM batteries, perhaps they could give me the model number of those batteries so I can look up the weight?

[Winterbagoal]

Probably the 8240 model. Dual purpose, maintenance free, somewhere around 65 to 75 Ah. That's what my Navion came with.

[creativepart]

I think other fuse owners have said the batteries were Group 24. That's a smaller size and generally they are limited because of size to a max of 85 amp hours. I usually see ratings of 65aH on these, up to the max of 85aH.

Winnebago seems to have spec'd "dual purpose Marine/RV" batteries there. Especially since they gave you a CCA rating for the battery. When you see the Marine/RV battery description and a CCA (cold cranking amps) rating you are not seeing true deep cycle batteries. They are dual purpose in that they are "car starting" batteries for starting a boat motor, and deep cycle for running trolling motors, again for small boats. But that makes them less than idea for RV house power storage.

Other fuse owners have stated - but I have no real experience on this - that there is enough room in the battery compartment for two Group 31 batteries. Group 31 batteries are physically larger and because of this can have more storage amperage. The typical amp hour rating is 100 aH.

Naturally, larger Lead Acid batteries weigh more - more lead, more weight, more energy storage. Group 31 100ah batteries typically weigh 60 to 70 lbs. Typical Group 24 85ah batteries are in the mid-50 pounds. So, the weight difference isn't great at all.

The lightest weight batteries would be the 3 to 4 times more expensive Lithium Phosphate batteries like Battleborn. Group 31 100ah LiPo batteries are around 25lbs.

With Lead Acid batteries you are limited to using approx 50% of the total amp hour capacity in a duty cycle without causing some damage to the battery and shortening it's duty life. So, if you get 2-85aH AGM Group 24 batteries you'd have a total of 170aH of storage with essentially 85aH available. The same goes for Group 31 - but you'd have 200aH total and 100aH available for general use. You can drop below 50% during a duty cycle but each time you do so shortens the effective life of the battery.

LiPo batteries don't have this restriction. You can repeatedly use as much as 90% of the available amp hours without much degradation of the battery life. Plus they charge much faster and they hold a charge much better. They just cost 3 times as much as AGMs.

There have been a number of fuse owners that chose to use 2-Group 31 AGMs and I've yet to hear of anyone reporting any issues with the weight of the batteries on the hanging battery rack. But that's not very comforting I understand. Of course, a welding shop could easily reinforce the battery compartment in minutes.

Be careful, if you go to an auto battery shop and tell them you need deep cycle batteries they are VERY likely to sell you some more Dual Purpose Marine/RV batteries and this is really not your best choice. They will work, but generally are better at starting engines than being a deep cycle battery.

If you do a LOT of dry camping or boondocking consider getting as much amp hours of storage as you can. If you mostly camp with shore power or generator available you'd probably do fine with AGMs again. But consider getting true deep cycle AGMs NOT dual purpose and getting the 85aH rated batteries rather than 65aH rated versions.

Here are some choices for Group 24 batteries. Most will cost between $250 and $325 each:

https://www.amazon.com/Fullriver-Gro.../dp/B00LU2GSPI

https://www.amazon.com/VMAX-SLR85-Cy.../dp/B0755M1QVH

https://batteryguys.com/products/lifeline-gpl-24t

I do not know of anybody selling Group 24 sized Lithium batteries at this time.

[Winterbagoal]

Forgot to mention, if they were the Napa 8240 dual purpose maint-free batteries, they weigh around 45lbs each.
If you're even thinking about switching to lithium, here's Relion's spec page for their products, including sizing info....
https://relionbattery.com/products/lithium

So far, mine are working well, as drop in replacements for the Napa 8240s. Good support from them, too.

[AJMike]

Originally Posted by Winterbagoal

Probably the 8240 model. Dual purpose, maintenance free, somewhere around 65 to 75 Ah. That's what my Navion came with.

Thanks for the reply but the battery that came with our Fuse was not maintenance free. It was almost impossible to add water to the battery and that was the main reason that I started to consider replacing it.

They seem to have equipped your Nation with better batteries than those in the Fuse.

[AJMike]

Originally Posted by Winterbagoal

here's Relion's spec page for their products, including sizing info....
https://relionbattery.com/products/lithium

Thank you.

My first thought was to replace the current batteries with 85AH or higher rated AGMs, but the weight concerned me. The last thing I wanted was to find myself with 2 batteries splattered all over some road somewhere because they were too heavy for the hang-down shelf. Perhaps it would be worth checking with the local welding shop to see if they can make sure the shelf is sturdy enough to handle 140 pounds.

The alternative, of course, is Lithium and I spoke with the Battle Born tech for about 30 minutes to find out what issues there might be and what I would have to do to install L-I batteries to replace the current house batteries. He was very helpful but the cost seems a bit high for 2 batteries, an alternator isolator and, I suppose, a battery monitor - probably in the $3000 range - and I am uncertain about the wisdom of installing only one battery and adding a second later to spread the cost out.

In doing some checking I also found Dakota L-I batteries and their webpage says. that they charge to 12.8 volts instead of 14.4. I don't know if that means that they would not require an alternator isolator or not, but that might be one possible solution. The webpage says that they are made in the US (Battle Born says they are the only company to make L-I batteries in the US) and they are a bit less expensive, but I have no idea as to their reliability.

I also need to check with Relion. I called them last week but got no one, so I will give them another call. L-I may well be overkill considering that we don't use all that much power, but I do find that the batteries are down to 12.1 or so volts in the morning and that worries me. It seems I clearly need more power or more solar; perhaps both.

[AJMike]

Originally Posted by creativepart

I think other fuse owners have said the batteries were Group 24. That's a smaller size and generally they are limited because of size to a max of 85 amp hours. I usually see ratings of 65aH on these, up to the max of 85aH.

The batteries in our Fuse were Group 24 and according to Winnebago they were NAPA 550 CCA rated, 65AH. The closest thing I could find at the NAPA webpage weighed 45 pounds each so 90 pounds total weight, and that seems a bit far from 140 pounds. I suppose I worry too much. I could not find the actual batteries and that is why I posted the question.

I have measured the space in the battery enclosure and it is 16 x 12 x 12. While the width and height are fixed there is probably some hang-over space in the depth and it may be possible to fit 2 L-I batteries in there. I just need to figure out how much actual space there is when the door is closed.

We don't do a lot of dry camping, and what we do is usually limited to 2 days at any one site. After that we go someplace else and the drive charges the batteries back to full, so our usage is limited. But if we are dry camping at someplace where there is little sunlight we have real issues. My wife likes to go to a hot mineral water spa that has dry camping in a tree shaded area and rules that say no generator usage at all. One day there and we were almost out of power so I do need more reserve than we currently have. Then I had to drive the RV out of the campground to charge the batteries but doing that is a real pain.

[powercat_ras]

Whatever you do don't replace with the OEM Group 24 NAPA RV/Marine. Get true deep cycle batteries. They weigh more but work better and last longer.

Measure your battery area and if height allows it, consider two group 24 6 volt golf cart batteries connected in series. Costco sells them for about $ 80 each.

[AJMike]

Originally Posted by powercat_ras

Whatever you do don't replace with the OEM Group 24 NAPA RV/Marine. Get true deep cycle batteries. They weigh more but work better and last longer.

Measure your battery area and if height allows it, consider two group 24 6 volt golf cart batteries connected in series. Costco sells them for about $ 80 each.

I was told today that Costco is going to carry Lithium batteries for about $700 each. That might be worth waiting for.

[Winterbagoal]

Originally Posted by AJMike

Thanks for the reply but the battery that came with our Fuse was not maintenance free. It was almost impossible to add water to the battery and that was the main reason that I started to consider replacing it.

They seem to have equipped your Nation with better batteries than those in the Fuse.

On page 6-8 of the 2018 Fuse OM, there's a picture of 2 large batteries in an exposed tray next to the propane tank. The batteries have "8231" on the side of them. If they are NAPA 8231, does that ring a bell? They don't look like they have cell caps on them, so this may be a "sample picture", and not a true representation of your actual original batteries.

[345 desoto]

FWIW, This is what I just bought (2) for our '88 Chieftain w/hanging battery tray. They're 63lbs each...UPG 12V 100AH 21000 AGM Battery. https://www.ebay.com/itm/130927958837

[AJMike]

Originally Posted by Winterbagoal

On page 6-8 of the 2018 Fuse OM, there's a picture of 2 large batteries in an exposed tray next to the propane tank. The batteries have "8231" on the side of them. If they are NAPA 8231, does that ring a bell? They don't look like they have cell caps on them, so this may be a "sample picture", and not a true representation of your actual original batteries.

Unfortunately the batteries that came with our Fuse were not maintenance free. One of the issues I had was leakage of the electrolyte out of the top caps after boondocking at some BLM land after a particularly bad rain. The ground had dried but the previous campers had left large ruts in the ground getting out and our Fuse rocked and rolled enough that we had a fair amount of spillage from the top caps of the batteries and I had to have the storage shelf cleaned and repainted.

It does seem the the OEM batteries were something like 65AH rated and probably weighed something like 45 pounds each. If I am going to replace them with higher AH rated batteries I think I am going to have to have the shelf reinforced to hold the additional weight. I guess that means that I will have to find some shop to weld supports for the shelf. Either that or go with Lithium since they weigh so little.

[Winterbagoal]

Originally Posted by AJMike

Unfortunately the batteries that came with our Fuse were not maintenance free. One of the issues I had was leakage of the electrolyte out of the top caps after boondocking at some BLM land after a particularly bad rain. The ground had dried but the previous campers had left large ruts in the ground getting out and our Fuse rocked and rolled enough that we had a fair amount of spillage from the top caps of the batteries and I had to have the storage shelf cleaned and repainted.

It does seem the the OEM batteries were something like 65AH rated and probably weighed something like 45 pounds each. If I am going to replace them with higher AH rated batteries I think I am going to have to have the shelf reinforced to hold the additional weight. I guess that means that I will have to find some shop to weld supports for the shelf. Either that or go with Lithium since they weigh so little.

We must travel in similar areas. Our Navion has done some fairly intense rocking and rolling on many uneven roads/trails/dirt tracks, so I know exactly what you mean.
I only suggested the Napa 8240 as they fit the profile, except for the open cells part. Around 65Ah and around 45lbs and they're GR24. It's what we had in our tray from the factory. I had to modify the edges of the base to shoehorn in the Relion GR31 units. Pricey, but so far, worth every penny.

[Winterbagoal]

Originally Posted by AJMike

I was told today that Costco is going to carry Lithium batteries for about $700 each. That might be worth waiting for.

If you're not in a hurry, I would try to research this option, too.

[AJMike]

Originally Posted by Winterbagoal

I had to modify the edges of the base to shoehorn in the Relion GR31 units. Pricey, but so far, worth every penny.

Are those AGM? Or Lithium?

[Winterbagoal]

Originally Posted by AJMike

Are those AGM? Or Lithium?

LiFePO4 - lithium iron phosphate. See prior post with link to Relion website.
RB100-LT - rated at 100Ah each (actual rating is just over 100Ah, but that's the nature of these things) and can be safely charged/discharged down to -4F. I live in Ontario, Canada, and it gets cold here, so I wanted a lithium option that could charge, as well as be discharged, in colder weather. We sometimes stay at places where the overnight temps get below 32F, so it helps there, too. Plenty of off grid power from them for our style of camping, so it's all good.
https://relionbattery.com/products/lithium/rb100-lt

[AJMike]

Originally Posted by Winterbagoal

LiFePO4 - lithium iron phosphate. See prior post with link to Relion website.

I called them the other day and they referred me to one of their sales people for technical information and pricing. I tried calling but was only able to leave a message and will try to reach him again today.

The problem with Lithium, I think, is that a single battery will not be enough and 2 is out of my budget, especially when I would also have to install an alternator isolator, but it may be my only real solution since presumably 2 AGMs can only supply 50% of their rated power while Lithium can supply more. I don't know exactly how much more, but more.

[Winterbagoal]

What does an alternator isolator do, and why do you think you need one? Relion batteries have a built in BMS that prevents most common problems that might damage FLA batteries. If the concern is over charging.

You can discharge lithium batteries down to zero if you need to, but they need to be fully recharged afterwards. You can take them very low, with little voltage drop, and they won't be seriously damaged. It may shorten the number of full charge discharge cycles, and there are charts that suggest the various levels of rate of discharge and how it will affect those numbers. Usually supplied by the individual manufacturers.

Relion has some single battery/high Ah options. Maybe something like that would work for you.
Good luck with it. Relion does have excellent product support, but they're probably under the same restrictions as the rest of us, for now. Patience?

[AJMike]

Originally Posted by Winterbagoal

What does an alternator isolator do, and why do you think you need one? Relion batteries have a built in BMS that prevents most common problems that might damage FLA batteries. If the concern is over charging.

My ignorance is showing here, so please bear with me.

Every tech I have spoken with says that a Lithium battery will burn our an alternator if it (the alternator) is not isolated from the battery so that it only provides current to the battery for a limited period each time. That is, it charges, then stops charging, then charges, then stop charging, and so on. The techs that I spoke with referred to this as an isolator for the alternator although some said that it is the same thing as a DC-to-DC charger. So the problem is not over-charging the batteries but over-using the alternator to charge the batteries.

As I said, this is what I have been told, but I have no real technical knowledge of this issue. I am only telling you what Battle Born and some of the local solar shops have told me. If this does not apply to Relion batteries it would be good to know.

Originally Posted by Winterbagoal

You can discharge lithium batteries down to zero if you need to, but they need to be fully recharged afterwards. You can take them very low, with little voltage drop, and they won't be seriously damaged.

So how do you know when you are getting close to the end of the battery power if the voltage does not drop? Do you need a battery monitor?

Originally Posted by Winterbagoal

Relion has some single battery/high Ah options. Maybe something like that would work for you.

Here all I have is guesswork.

If I start with 12.6 volts (shown as 100%) and end up overnight with 12.1 volts, then I assume I am using something like 40% of the battery capacity (that is a guess). Since my 2 batteries are 130AH total I assume I am using 40-45AH and to do that for 2 days in a row without much solar power being generator due to too much shade I would think that 90AH might not be enough. That is why I am uncertain about a single Lithium battery.

If on the other hand 12.1v (or 11.9v as of yesterday morning) is only 35% or 40% of capacity then a single 100AH Lithium battery would be more than enough, and of course I get different answers from the sales and tech people at different companies.

Originally Posted by Winterbagoal

Relion has some single battery/high Ah options. Maybe something like that would work for you.
Good luck with it. Relion does have excellent product support, but they're probably under the same restrictions as the rest of us, for now. Patience?

As soon as I can get in touch with the Relion sales guy I will ask about a single battery solution. If that would work then I could add a second battery, if needed, later, but the issue is also whether or not I need that alternator isolator/DC-to-DC charger.

[Winterbagoal]

Originally Posted by AJMike

My ignorance is showing here, so please bear with me.

1) Every tech I have spoken with says that a Lithium battery will burn our an alternator if it (the alternator) is not isolated from the battery so that it only provides current to the battery for a limited period each time. That is, it charges, then stops charging, then charges, then stop charging, and so on. The techs that I spoke with referred to this as an isolator for the alternator although some said that it is the same thing as a DC-to-DC charger. So the problem is not over-charging the batteries but over-using the alternator to charge the batteries.

As I said, this is what I have been told, but I have no real technical knowledge of this issue. I am only telling you what Battle Born and some of the local solar shops have told me. If this does not apply to Relion batteries it would be good to know.



2) So how do you know when you are getting close to the end of the battery power if the voltage does not drop? Do you need a battery monitor?



3) Here all I have is guesswork.

If I start with 12.6 volts (shown as 100%) and end up overnight with 12.1 volts, then I assume I am using something like 40% of the battery capacity (that is a guess). Since my 2 batteries are 130AH total I assume I am using 40-45AH and to do that for 2 days in a row without much solar power being generator due to too much shade I would think that 90AH might not be enough. That is why I am uncertain about a single Lithium battery.

If on the other hand 12.1v (or 11.9v as of yesterday morning) is only 35% or 40% of capacity then a single 100AH Lithium battery would be more than enough, and of course I get different answers from the sales and tech people at different companies.



As soon as I can get in touch with the Relion sales guy I will ask about a single battery solution. If that would work then I could add a second battery, if needed, later, but the issue is also whether or not I need that alternator isolator/DC-to-DC charger.

1) OK, I'm new to this too. I just put 4,000 miles on my 220A MB alternator, and as far as I can tell, with no ill effects. Batteries were full at EOD of driving.
It is my opinion that the alternator puts out what it puts out in terms of volts and amps, depending on how quickly the engine running spins the rotor, as far as I know. So, how does a battery "burn out" an alternator? If the battery has the capacity to absorb the amps being generated, then I would think that's normal. When the battery capacity is reached, the BMS will slow and then stop any further charging, and the alternator will do whatever they do when the batteries it feeds are full. The voltage regulator kicks in and/or redirects it into the excess amps bucket? Sorry, but I don't get this depiction of a lithium battery as some blood sucking vampire that will kill your alternator. If others can explain it (dumb it down for us) I'm all ears.

2) I suppose you could add a battery fuel gauge if you like. I haven't, and I just use the voltages on my One Place, and the (probably better one) Zamp ZS-30A Solar Charge Controller. If they tell me I'm FUL, then I take their word for it. I have read that lithiums are full anywhere from 13.4 resting to 13.8 resting voltage. If I'm in those ranges when we stop and start to use our off grid power, I figure I'm good until morning. I think I mentioned before that I'm not a micro-manager of my battery bank. I have 200Ah (210Ah actually, but that's another lithium battery oddball story) and that is probably more than all the overnight off grid draws I could put on them, including the propane solenoid and the Norcold DC0061 fridge. I deal with replenishing them the next day. Solar (300W), driving to a new location, running the generator to heat something up, or being plugged in to shore power, are my usual options, and together they seem to do the trick.

3) I would be guessing too. If you can figure out what your average off grid usage might be in amp hours, you'll be all set to determine what will work best for you in terms of batteries.
If you use 45Ah overnight for your average, then a 100Ah lithium would do you for several days off grid, assuming some level of recovery charging greater than zero. Even just idling your chassis engine for a while, if possible, would help replenish what you've used. A few amps of solar, run your generator if you have one when you're doing something else, or go for a short drive, would all help for the next night off grid. Even rainy days can produce a few amps of solar charge over the daylight hours.
I have had (in 3 different motorhomes) FLA, AGM, and now LiFePO4 batteries, and can tell you I prefer them in the reverse order. If you don't want tp jump into lithium right away, AGMs are probably the next best thing, but they're getting pricey, too. And they're twice the weight of comparable capacity lithiums. For my weight challenged Navion, the choice was clear. So far, I'm glad I spent the money and got the Relions. It was a tough call, leap of faith type of decision, but so far it's worked out well. I don't give how much power we have for off grid a second thought. If I do look at the resting voltages on the displays, and they look reasonable, I'm happy.
Without the "alternator isolator".

As I said, I'm new to this too. It can be a roller coaster learning curve at times, and I'm just along for the ride.