Sorry. One more battery question

[AJMike]

People have been great giving me information about replacing my undersized AGMs with either new AGMS or Lithium, and I have spoken with Battle Born and exchanged email with Dakota about installation.

One thing no one has really addressed is whether or not a Lithium installation requires some new device on the generator charge line as on the alternator charge line. Both BB and Dakota insisted that I would need either a BIM or a DC-DC charger for the alternator but no one specified if I needed something similar for the generator or for shore power. For those who have done this, have you needed to install anything for the generator charge line or for shore power (or are those the same power supply)? And, if so, what?

OK. I guess that is 2 questions ...

[creativepart]

Nope, the generator does nothing but power your converter/charger or inverter/charger which ever you have.

Running the generator is the same as plugging into shore power. So, once your charger is set up for lithium you are done.

[AJMike]

Originally Posted by creativepart

Running the generator is the same as plugging into shore power. So, once your charger is set up for lithium you are done.

I don't understand.

As far as I know there are 4 sources of power for the house batteries - the alternator, solar panels, the generator and shore power. I suspect that the last 2 are really the same in that they both pass through a converter that converts the AC to DC to charge the batteries (a device which I think is called a charge converter).

For Lithium batteries the alternator is protected by a DC-DC charger and the solar power is processed by the solar converter set for Lithium. But I am not aware of any setting on the "charge converter" for wet cell, AGM or Lithium. Certainly there is no visible control in my Fuse for that setting, or at least nothing that I have seen in 18 months of use. How do you set the charger for Lithium? As far as I know it is not accessible anywhere in the RV, although perhaps I just don't know where to look.

Or am I completely misunderstanding your post?

[creativepart]

Yes, four sources of power. But not four different charging devices.

1. Shore power charges via the converter/charger or Inverter/charger (which ever applies)
2. Generator power - same as shore power
3. Solar Power - charges via the Solar Charge Control
4. Alternator Power - charges directly or through an added DC to DC charger

The shore power and generator just provide power to the main house charger. They don't provide anything but A/C current for those chargers.

The Solar Charge Controller is a totally separate charger. It is directly connected to the battery bank and it can be charging at the same time as the main house charger.

The alternator is it's own power source and it uses the built in voltage regulator to apply current again directly to the batteries. This is the source that's not tailored for Lithium and that why its recommended to either limit the time that it is connected to the battery bank, or it connects to a new additional charger made just for this purpose.

Look at the plug from the RV that plugs into shore power as being exactly the same as the generator when it's running.

As for your Converter/Charger or inverter/charger... I believe the RV you're talking about has the Converter/Charger you will need to learn what model you have installed and if there are "remotes" or circuit boards that need to be changed so that you can adjust the charging profile of the charger. I think Kayak73 posted that he added an inexpensive remote that let him change the charging profile. But I'm not familiar with the details of your RV.

Alternatively, it's possible that your converter/charger is already set up for AGMs or can be. If so, that's not ideal but does usually work at the AGM setting if you must.

Some people change out the converter/charger to accommodate LiPo batteries, but it's not always required.

[AJMike]

Well, this is both much more complicated and much more expensive than I imagined at first. I had the impression that changing to Lithium would require an expenditure for the batteries but not much more, but now I see that is completely wrong.

1) $2000 for batteries,
2) $500 or so for a DC-DC charger and installation,
3) $500 or so for a new charger for the new batteries and installation,
4) $400 or so for a battery monitor and installation,
5) $600+ to upgrade solar to provide charge for extra battery AH.

A local shop gave me an estimate of $3500+ without the extra solar. That is just too much for my budget so I guess I will look at AGM again.

Thanks for all the help. At least I can stop this thing before I end up spending much more than I expected, but it does leave me with another question about another subject (and another thread) ...

[creativepart]

As was mentioned before, the cost to have someone supply the parts, materials and installation is about twice the cost of DIY. So, $3,500 for them to do it or ~$2,600 by my calculations for the DIY cost (two LiPo batteries will cost ~$1,900 no matter who does the job). DIY solar panel upgrade would be about $250 more.

It is understood that you’ve already stated you don’t feel comfortable doing DIY for this job.

By the way, with more battery bank amp hours and the battery monitor you’d probably learn that 300w of solar is fairly adequate. More solar is always nice but it’s battery storage that is most helpful.

A budget priced option with big results would be to use Group 31 100aH AGMs instead of lithium. This eliminates numbers 2 and 3 and changes number one to ~$650.

You would vastly increase your dry camping power supply for about $1200. Going to LiPo is ideal and if budget permits is the optimum way to go. But we can only do what we can only do.

[AJMike]

Originally Posted by creativepart

It is understood that you’ve already stated you don’t feel comfortable doing DIY for this job.

I am just not handy with tools and I don't have the expertise to know how to go about doing something like installing a DC-DC charger. I am pretty sure that if I spent the time studying I could figure out how to do the actual install and, when I realized I had screwed it up, I would probably do a better job the second time, but that is not a good recommendation for my mechanical expertise.

When I was a kid I took everything apart and put them all back together. The only problem was that I always had parts left over after reassembly and I don't think they were just extra parts left around by the manufacturer ...

Originally Posted by creativepart

A budget priced option with big results would be to use Group 31 100aH AGMs instead of lithium. This eliminates numbers 2 and 3 and changes number one to ~$650.

You would vastly increase your dry camping power supply for about $1200. Going to LiPo is ideal and if budget permits is the optimum way to go. But we can only do what we can only do.

This is the direction I am currently looking at. Interestingly enough it was the first decision I made when I thought I should upgrade the batteries and I only got side-tracked into looking at Lithium because of the idea of having 200AH or power, so I am going back to what I originally planned to do.

The issue now becomes finding a good 115AH AGM battery for the RV and making sure that the hanging battery storage area is strong enough to hold the extra weight. I think the pair of OEM batteries probably weighed about 90 pounds together and 2 115AH AGM batteries are probably about 130 pounds. I will need to make sure that the hanging straps are adequate for the added weight.

I had been looking at Fullriver 115AH AGM batteries but if there is a better choice I would appreciate knowing about it. Those Fullriver batteries are about $325/each.

[345 desoto]

If you could put up with only 100AH AGM's these are what I just bought (2)….https://www.ebay.com/itm/130927958837

[creativepart]

It should be easy to create a list of Group 31 AGM true deep cycle batteries, like the FullRiver. You'll find cheaper batteries from Asia, and more expensive Batteries like Lifeline. But the difference between the cheaper FullRiver and the expensive Lifeline is about $30. So, that's not a big difference.

The Universal Batteries from Asia are $140 cheaper and I don't know if that means they are a good deal or not well made.

Make a list and pick the battery and price point that seems best to you. You almost can't go wrong - or very far wrong. If you make a poor choice you may not know it for a couple of years anyway.

[Winterbagoal]

Best bang for the buck, in my opinion....

https://www.samsclub.com/p/duracell-...gm/prod3590232

[creativepart]

Originally Posted by Winterbagoal

Best bang for the buck, in my opinion....

https://www.samsclub.com/p/duracell-...gm/prod3590232

Not a true deep cycle storage battery. Those are "dual purpose" boat batteries for starting outboards and running trolling motors. But many people use them in RVs that's for sure.

I used them 10-years in a travel trailer I owned. They worked OK, but didn't last long and I always carried a portable generator (2 of them actually). I didn't know they weren't really deep cycle batteries at the time.

[AJMike]

Originally Posted by Winterbagoal

Best bang for the buck, in my opinion....

https://www.samsclub.com/p/duracell-...gm/prod3590232

The AGM batteries I have been looking at all have an AH rating, but the specs for this battery are the first that I have seen that lists AH based on how the battery is used:

1 amp hour rate:68.2
100 amp hour rate:110
20 amp hour rate:105
3 amp hour rate:85
5 amp hour rate:86
6 amp hour rate:87.4
8 amp hour rate:90

This makes me wonder how all of the other battery ratings compare to this one. When I see 115AH is that at 1 amp? 3 amps? 5 amps? Or something else?

How can I compare batteries when I don't even know if I am comparing apples to apples or apples to oranges?

The battery is certainly less expensive and Costco does not have any competing AGM batteries, but is it a good RV house battery? I just don't know enough about rV batteries, or batteries in general. The cost is certainly low compared to other batteries I have been looking at, and worth the cost of joining Sam's Club, but are they good RV house batteries?

[AJMike]

Originally Posted by creativepart

It should be easy to create a list of Group 31 AGM true deep cycle batteries, like the FullRiver.

Perhaps, but I am not sure how I go about finding out what batteries are right for the list. One of the issues I have had is knowing what batteries are truly RV batteries and what batteries are not, so how do I know which batteries should be on that list.

At the moment I only have Fullriver, and I only have that because people on these forums have verified that they are truly deep cycle batteries and are good for use as RV house batteries. I don't know of any others.

[creativepart]

Originally Posted by AJMike

Perhaps, but I am not sure how I go about finding out what batteries are right for the list. One of the issues I have had is knowing what batteries are truly RV batteries and what batteries are not, so how do I know which batteries should be on that list.

Just Google Group 31 12 volt Deep Cycle AGM batteries. Ignore any "dual purpose" or "Marine/RV" batteries. Those are not true deep cycle. Ignore those that promote their CCA amps. Those are cold cranking amps... again they are engine starting batteries hence the "crank" in CCA. And, that list you posted with different amps at different periods of time, that most of the time means it's not a true deep cycle. A true deep cycle will say 100 ah (or whatever) and that's pretty much it. It delivers 100 ah period.

In general you can also tell by the cost. True Deep cycle batteries cost more because they have thicker plates inside and more robust casing to hold thicker plates. It's rare to see true deep cycle Group 31 100ah 12 volt AGM batteries much below $275. The most expensive are over $400.

A Google search like I suggested will offer a LOT of options that are not true deep cycle. But you'll be wise enough to pick out the real "storage" batteries and avoid the "engine-starting-and-oh,-by-the-way-we-can-store-power,-too" batteries.

[Goodspike]

Originally Posted by creativepart

The Universal Batteries from Asia are $140 cheaper and I don't know if that means they are a good deal or not well made.

If there's one thing the Chinese are good at it's putting lead in products.

[AJMike]

Originally Posted by creativepart

In general you can also tell by the cost. True Deep cycle batteries cost more because they have thicker plates inside and more robust casing to hold thicker plates. It's rare to see true deep cycle Group 31 100ah 12 volt AGM batteries much below $275. The most expensive are over $400.

I know little about AGM batteries other than what I have learned on this and other RV forums, but I assumed Lifeline was one of the better deep cycle RV house batteries. it certainly is one of the most expensive at > $400 for 125AH, but it is listed as also a Marine battery. And its specs list CCA as well as AH ratings.

From what I have read I thought it was one of the best RV house batteries, but does the CCA rating remove it as a true RV house battery?

[creativepart]

Lifeline is a company with a great reputation for building a good battery. But they make many batteries for many industries and uses. So, you can certainly find LIfeline true deep cycle AGMs and Lifeline Dual Purpose Marine/RV AGMs. Just because it's a Lifeline battery that doesn't mean all of their batteries are one kind or another.

The comments I made about CCA and and such are just clues to look for. So when someone points you to a $169 Walmart Marine/RV AGM battery you will be able to tell it's not the same as a $370 Lifeline AGM.

Most any 12v battery including a deep cycle battery can start an engine, it depends on how the battery is built. Is it built to send out hundreds of amps in 5 sec bursts to crank an engine starter, or is it designed to put out 50 amps continuously and then recharge and do it again and again.

[al1florida]

Originally Posted by AJMike

The AGM batteries I have been looking at all have an AH rating, but the specs for this battery are the first that I have seen that lists AH based on how the battery is used:

1 amp hour rate:68.2
100 amp hour rate:110
20 amp hour rate:105
3 amp hour rate:85
5 amp hour rate:86
6 amp hour rate:87.4
8 amp hour rate:90

This makes me wonder how all of the other battery ratings compare to this one. When I see 115AH is that at 1 amp? 3 amps? 5 amps? Or something else?

How can I compare batteries when I don't even know if I am comparing apples to apples or apples to oranges?

The battery is certainly less expensive and Costco does not have any competing AGM batteries, but is it a good RV house battery? I just don't know enough about rV batteries, or batteries in general. The cost is certainly low compared to other batteries I have been looking at, and worth the cost of joining Sam's Club, but are they good RV house batteries?

AJMike, There is a simple answer to all the numbers that are listed for the batteries you looked at.
The batteries that are used in RV's have AH ratings using the "20 hour" rate. Typically that is: " battery that can deliver 5 amps for 20 hours before it is discharged would have a 100 amp hour rating 5 Amps X 20 Hours = 100Amp Hours".

Just ignore all the other ratings in comparing batteries.

It is not that the other AH rating you listed are incorrect, it is just a standard that is used for RV usage is the 20 hour rate.

[Winterbagoal]

Originally Posted by creativepart

Not a true deep cycle storage battery. Those are "dual purpose" boat batteries for starting outboards and running trolling motors. But many people use them in RVs that's for sure.

I used them 10-years in a travel trailer I owned. They worked OK, but didn't last long and I always carried a portable generator (2 of them actually). I didn't know they weren't really deep cycle batteries at the time.

I understand that, that's why I said "best bang for the buck". The price is low, but the product will do what he wants it to do. And being dual purpose, it will likely recharge faster than a true deep cycle. Pay less, but get something that will work just fine for the OP's needs.
As a second thought, he could use 2 AGM GC2 6V batteries in series, but you're getting back up in price there.

[al1florida]

Originally Posted by AJMike

Well, this is both much more complicated and much more expensive than I imagined at first. I had the impression that changing to Lithium would require an expenditure for the batteries but not much more, but now I see that is completely wrong.

1) $2000 for batteries,
2) $500 or so for a DC-DC charger and installation,
3) $500 or so for a new charger for the new batteries and installation,
4) $400 or so for a battery monitor and installation,
5) $600+ to upgrade solar to provide charge for extra battery AH.

A local shop gave me an estimate of $3500+ without the extra solar. That is just too much for my budget so I guess I will look at AGM again.

Thanks for all the help. At least I can stop this thing before I end up spending much more than I expected, but it does leave me with another question about another subject (and another thread) ...

I have some comments about the costs and "needs" you have listed above.
1) the cost for lithium is about right. There are very definite very good reasons to go with lithium. In my opinion a lot depends on what your dry camping/boondocking plans are. If you are going to dry camp for 2-7 days and then go back on shore power for a few to many days, there is no real need to go to lithium. This statement is tempered by just how much power you take out of your batteries. If your life style means you take 50-60% of your AH capacity every day, then you really should put a priority on lithium. Getting lead acid (even AGM lead acid) charged from 50% to 90-95% ever day is not a simple matter of running a generator for an hour or two.
2) There are less expensive DC to DC chargers available. A competent installer should not need more than 30 minutes to install, plus 2 new cables. You can find install manuals that give details on the install. Well worth reading.
3) I don't known if you really need a new converter/charger. Probably not. Battle Born should be able to advise you if their batteries need a different charger than what is in your RV
4) This has NOTHING to do with installing lithium. If you are going to dry camp/boondock for more than overnight or 2 days, you MUST have a battery monitor. You are flying blind w/o the monitor.
5) Same with solar. You don't need more solar just because you go to lithium. Just the opposite. You can put more AH into lithium in an hour or two of generator time than you will ever get into lead acid. If you stay with AGM and use 30-50% of your battery AGM capacity each day you really should upgrade your solar.