Lead Acid, Lithium Hybrid Comment thread

hbn7hj · 05-13-2018, 03:28 AM

Just a thread for question or comment.

A major advantage, so far, is access to the 80%-100% Lead Acid charge level for those without solar. 44 amp hours is a lot of power that the generator people have difficulty getting. The under hood generator folks may have a shot at it.

We will experiment with procedures to reduce intervention during the charge cycle. After the generator run turn on the DC to DC charger with solar directed to the Lithium battery. I can't do that now, without monitoring, because the solar controller is old and dumb.

We will see how it works just keeping the LA at 100% and using the Lithium. Two hundred amp hours of power available is a lot.

My thought is the system arguably matches the usable power of 600 AH of AGM batteries.

hbn7hj · 05-21-2018, 10:05 PM

I've added the second lithium battery and the 1500 watt whole house inverter. Will give results on the other thread when I get them. I'm home for a few days and not using any power.

What I am interested in is other's comments. It appears that as good as the dual system appears to me to be there isn't much interest in anyone else doing it. Why? Cost? Space? Effort? It certainly was a lot of work but it functions so very, very well. Both banks at 100% every evening with a minimal generator run.

What am I missing? B's are made for moving, not sitting, and this is a B forum. Maybe that is the difference.

I intend to put it in a B this winter. There certainly is less space to work with.

booster · 05-21-2018, 10:16 PM

Quote:

Originally Posted by hbn7hj

I've added the second lithium battery and the 1500 watt whole house inverter. Will give results on the other thread when I get them. I'm home for a few days and not using any power.

What I am interested in is others comments. It appears that as good as the dual system appears to me to be there isn't much interest in anyone else doing it. Why? Cost? Space? Effort? It certainly was a lot of work but it functions so very, very well. Both banks at 100% every evening with a minimal generator run.

What am I missing? B's are made for moving, not sitting, and this is a B forum. Maybe that is the difference.

I intend to put it in a B this winter. There certainly is less space to work with.

I think we touched on the seeming lack of interest in some of the early discussions, and likely still true. Most people either don't know, or don't care, that they are not getting full capacity and are shortening the life of their batteries by continually short charging them.

I don't think the system will ever just take off on it's own, but if the Hymer setup proves to work out well, and the folks realize it is an improvement, and Hymer pushes that information out to the public, then it may gain some traction.

A ground up design of a system that carefully matched and tested compatibility of the parts and capacities could probably be totally plug and play, which would be necessary for large acceptance.

It almost seems like anyone who is interested enough in improved battery systems is also willing to go with the extra cost and complexity of the much larger and much more expensive lithium systems.

Bud · 05-22-2018, 02:38 AM

Hi hbn7hj,

I may just not be recalling and it is in the other thread, but what prompted your interest. Hey, and enough to pull it off!

Bud

hbn7hj · 05-22-2018, 03:44 AM

This is a post from a class C forum when they told me 4 AGMs were a better deal (not so) and said they would rather buy a Victron system at three times the price. (Backing up Booster's comments) All in all they blew it off. The hybrid system is so superior to a large AGM bank. The lead acid battery box is out in the cold, may as well put something useful in it. The lithium battery charges (5 times?) faster than lead acid reducing generator times considerably. The DC to DC charger is also a major asset. Both banks at 100% every night, rain or shine.

"I'm not tinkering. This is a full blown, so far successful, effort to increase the power capabilities of the RV without making changes beyond my capability. The rapidly increasing park space rental rate is the motivation. I could pay $50/day with no seasonal option but I refuse, so far. Off grid in cold temps are a challange and, yes, I have a catalytic heater which uses no electrical power.

My friends here in Moab had an 8 day stay (Diesel pusher) at $75/day. The place was booked. Supply and demand run the show and if I owned a park I'd charge that, too.

Soon I expect the off grid locations to start charging or increase rates. The two week stay limit wasn't there or was ignored not too many years ago. Will the geezer rate go away? Eventually I expect I'll have to change my destinations. The good news to me is many new RVs are not capable of off grid operation with their compressor fridges and limited battery bank. For $1300 I'm still in the game though I will expand to $3000."

hbn7hj · 05-22-2018, 04:59 AM

I travel in my B, I sit in my C. Four years ago the $15/day plus electric seasonal rate went to $50/day, no seasonal rate. The parks remain full, much to my surprise. When I plugged in power didn't matter, now it does, and if you want sat TV or even DVDs in the evening it takes a lot of generator time the next day.

I don't like AGM batteries. Everyone I know has ruined a set. I don't have the skills or desire to hang a large lead acid bank underneath the coach.

Last winter I spent a week at the Grand Canyon Mather campground.
Their generator hours are 8 to 10AM and 6 to 8PM. My guest was an almost Los Angeles Laker (blown out by injury, 6'7" so he had a shot.) He wanted to watch basketball in the evening. We did it but the batteries were severely depleted and couldn't recover the next day in the generator time allowed for the next night. It was restrictive to have to stay with the coach to run the generator for the two hours in the morning and two hours in the evening. The lithium option with the DC to DC charger solves all these problems with much less battery weight.

There are other problems to staying off grid. Not using the black tank stretches my stay time to two weeks when I have to move, anyhow.

That was my mindset when Booster mentioned a hybrid system and GeorgeRa mentioned the DC to DC charger. From there it all went together.

I spent six weeks in Moab putting it together and testing it with one lithium battery. It worked. Both banks at 100% every evening in cold temperatures. I went through 36 gallons of propane which is another issue.

Bud · 05-22-2018, 12:48 PM

"I went through 36 gallons of propane which is another issue."

Then I'm looking forward to your next thread.

Bud

hbn7hj · 06-26-2018, 12:11 AM

200 AH lithium system is working well in parallel with the LA system.With low nighttime temperatures in the 30's I find that a heated mattress pad (Electrowarmth AC version) overnight with inverter consumes around 30Ah per person.

The furnace takes more power than that set at 55F and consumes lots of propane. Use the mattress pad and keep the furnace off. Warming the coach in the morning loses some of the advantages, of course, but you are not heating a sieve all night.
Harry

MsNomer · 07-03-2018, 01:47 PM

You lost me at "generator." Never. We just got home from a 6-week trip. Never plugged in once even when it was occasionally available.

hbn7hj · 07-03-2018, 02:57 PM

Quote:

Originally Posted by MsNomer

You lost me at "generator." Never. We just got home from a 6-week trip. Never plugged in once even when it was occasionally available.

Yep, but when you don't move, have satellite TV, nights in the 30's and only 200 watts of solar it has to be. There are some days 200 watts is enough but not many.

With lithium the generator runs are mercifully short. Thirty minutes or less. The morning drones are gone.

hbn7hj · 07-03-2018, 11:47 PM

Today's generator run was 18 minutes. Lithium completed the lead acid charge and solar recharged the lithium. Both banks at 100% by late afternoon.

peteco · 07-24-2018, 02:32 AM

I see mention in this thread of another thread on the present topic. Can someone put a link here to the other thread please.

I am trying to get my ducks in a row for the day I dump my 5 cu ft Dometic RM2454 3-way fridge for a compressor fridge. I am leaning towards the Vitifrigo. I will need to upgrade the electrical system. This seemed daunting at first as I thought I would need at least 200 watts of solar plus the associated control system. I really don't want to deal with a solar install if I don't have to. I can see upgrading to a high capacity alternator to handle charging. We are typically on the move each day.

The discussion here has me thinking I don’t need solar at all. I could keep my two 6-volt lead acid batteries and add 1 or 2 lithium batteries. I hope they come down in price when I am ready. It looks like I could get by on 1. It would also be nice to be able to run the microwave.

My vehicle is a 2006 Roadtrek 210P.

booster · 07-24-2018, 02:38 AM

Quote:

Originally Posted by peteco

I see mention in this thread of another thread on the present topic. Can someone put a link here to the other thread please.

I am trying to get my ducks in a row for the day I dump my 5 cu ft Dometic RM2454 3-way fridge for a compressor fridge. I am leaning towards the Vitifrigo. I will need to upgrade the electrical system. This seemed daunting at first as I thought I would need at least 200 watts of solar plus the associated control system. I really don't want to deal with a solar install if I don't have to. I can see upgrading to a high capacity alternator to handle charging. We are typically on the move each day.

The discussion here has me thinking I don’t need solar at all. I could keep my two 6-volt lead acid batteries and add 1 or 2 lithium batteries. I hope they come down in price when I am ready. It looks like I could get by on 1. It would also be nice to be able to run the microwave.

My vehicle is a 2006 Roadtrek 210P.

This is where the hybrid system discussion started.

http://www.classbforum.com/forums/f2...ymer-7383.html

And here is more as Harry did the rest of the testing to get to what he wanted out a combo system.

http://www.classbforum.com/forums/f2...stem-7451.html

peteco · 07-24-2018, 03:06 AM

Quote:

Originally Posted by booster

This is where the hybrid system discussion started.

http://www.classbforum.com/forums/f2...ymer-7383.html

And here is more as Harry did the rest of the testing to get to what he wanted out a combo system.

http://www.classbforum.com/forums/f2...stem-7451.html

This setup sure looks like a great upgrade for older coaches. I have a lot more to learn about wiring upgrade, inverter upgrade, proper fusing, alternator upgrade, etc. These pieces are spread throughout this great forum thanks to booster, hbn7hj (Harry?) and others. If someone put all the pieces together in one "how to" that would be great (hint-hint).

hbn7hj · 07-24-2018, 05:53 AM

Solar is not necessary but the system documented is based on use of a generator. I don't think you need to upgrade the alternator but the system would be very different. I don't use the vehicle alternator.
Harry

booster · 07-24-2018, 12:55 PM

We have very little actual data on how different combos might work or need to be put together, as we have only had one system made.

Harry's system is a bit different than the the original premise in that he has quite a bit more lithium percent of the total capacity than the first ideas, and he uses multiple chargers.

Use patterns and how much human intervention would be acceptable would certainly help with trying to come up with something that might work well for you.

peteco · 07-24-2018, 01:38 PM

Quote:

Originally Posted by hbn7hj

Solar is not necessary but the system documented is based on use of a generator. I don't think you need to upgrade the alternator but the system would be very different. I don't use the vehicle alternator.
Harry

I was thinking the high output alternator could do the lithium charge during the morning drive. Or even charge while sitting still. Not as loud as the Onan. The Onan is still there as well, but would need to upgrade the charger, which might happen as well as part of the inverter/charger upgrade.

booster · 07-24-2018, 03:24 PM

It is possible that you could use the layout, that was posted in the other thread, that was aimed at having a nearly pure add on system for existing systems. It is in this post on Harry's discussion.

http://www.classbforum.com/forums/f2...html#post70505

I think a system like this could be "built in a box" and then put on a large two wire plug in to the existing system, so you could easily disconnect it if needed until refined.

One issue of concern would be charge rate off the alternator. It appears that many of the drop in lithium batteries want fairly low charge rates, so a high output alternator might be too much. Solutions might include using a DC to DC current limiting charger, finding a 100% duty cycle alternator of the right size, or finding an alternator that has double the output you need and using a Balmar regulator set to cut the output in half (to keep the alternator cool).

peteco · 07-24-2018, 03:57 PM

Quote:

Originally Posted by booster

One issue of concern would be charge rate off the alternator. It appears that many of the drop in lithium batteries want fairly low charge rates, so a high output alternator might be too much. Solutions might include using a DC to DC current limiting charger, finding a 100% duty cycle alternator of the right size, or finding an alternator that has double the output you need and using a Balmar regulator set to cut the output in half (to keep the alternator cool).

Any thoughts on how to size the alternator for this setup?

booster · 07-24-2018, 04:08 PM

Quote:

Originally Posted by peteco

Any thoughts on how to size the alternator for this setup?

I just did some looking at batteries, and if you did a small Elite battery system of maybe 60ah plus BMS, you might not have to do much special with the alternator setup and could use the standard Nations add on kit of 280 amps turned down to 180 amps (you can do that on a Balmar and still have the 50% temp cutback). Elite says they can charge at 3C so that would work well. The Elite BMS should be able to do the charged voltage shutoff for the lithium so a separate control for that wouldn't be needed. The Elite system would require a bit of assembly work, but is a much better setup IMO than the drop in batteries and not much more cost. I think it would be under $1000 for a 60ah setup. I saw a complete Elite 100ah system for about $1250 so that is not bad at all and could handle as much charging as the Nations would do without overheating.

At that point you just need the DC-DC charger like Harry used and some switches for control.

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