Winnebago Travato with Volta Lithium Battery System

[gerrym51]

How long have lithium batteries been around in rv's. lifespans done in a lab are not always the same as lifespans out 'in the wild".

not enough years have passed on this.. Lithium batteries in cars have been in longer however they keep changing also.

[Technomadness]

Originally Posted by gerrym51

How long have lithium batteries been around in rv's. lifespans done in a lab are not always the same as lifespans out 'in the wild".



not enough years have passed on this.. Lithium batteries in cars have been in longer however they keep changing also.

Lithium battery chemistry has been around for decades. Not so long in RVs, but then these people aren’t shipping product much different from the 1970s anyway.


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[Davydd]

Originally Posted by gerrym51

How long have lithium batteries been around in rv's. lifespans done in a lab are not always the same as lifespans out 'in the wild".

not enough years have passed on this.. Lithium batteries in cars have been in longer however they keep changing also.

Mine are going on 3-1/2 years and I don't see a drop off. The same batteries but a little older generation were installed in the Technomad's RV bus in 2011 and they had drop off after about 4 years which you can read about on their blog but they were much more abusive especially with high temperatures.

I think up to about a 400ah battery bank you can make a case for either AGM or Lithium ion, but there is no contest in my mind with an 800ah battery bank. You simply cannot cram enough AGMs physically or weight wise to be practical in a Class B.

[BBQ]

Originally Posted by Davydd

...

I think up to about a 400ah battery bank you can make a case for either AGM or Lithium ion, but there is no contest in my mind with an 800ah battery bank. You simply cannot cram enough AGMs physically or weight wise to be practical in a Class B.

Agreed.

For small installations, Li is an overkill.

For large installations in an RV, AGM is impractical, no matter the cost. Because of the weight and size.

YMMV

[wincrasher]

Oh, I don't know about that. I found the 250 ah install in my Travato to be quite useful. It gave me total peace of mind of not running the batteries down to nothing. I essentially stopped caring about how much power I was using and it was quite liberating. But I wasn't running an inverter - just the DC fridge and typical onboard systems. In that scenario, you are essentially equivalent to having 4 group 31 AGM's, but with only 2 drop-in lithiums. Standard alternator charging was fine, as your depth of discharge wasn't so severe.

My Xplorer has 500 ah hours in it and it's even better. The only thing to worry about is if you run the air conditioner for an extended time.

My new van will have over 800 ah. But it will also have a big inverter, and rapid 2nd alternator charging. It may be anxiety free as well, but that will largely depend on air conditioner use.

As they say, the more you have, the more you use.

[Davydd]

Originally Posted by wincrasher

Oh, I don't know about that. I found the 250 ah install in my Travato to be quite useful. It gave me total peace of mind of not running the batteries down to nothing. I essentially stopped caring about how much power I was using and it was quite liberating. But I wasn't running an inverter - just the DC fridge and typical onboard systems. In that scenario, you are essentially equivalent to having 4 group 31 AGM's, but with only 2 drop-in lithiums. Standard alternator charging was fine, as your depth of discharge wasn't so severe.

My Xplorer has 500 ah hours in it and it's even better. The only thing to worry about is if you run the air conditioner for an extended time.

My new van will have over 800 ah. But it will also have a big inverter, and rapid 2nd alternator charging. It may be anxiety free as well, but that will largely depend on air conditioner use.

As they say, the more you have, the more you use.

I said up to 400ah it was debatable. BBQ agreed but then said it was overkill and we have a few here that are AGM proponents. But you brought up a subject AGM proponents don't say much about and that is running batteries down completely which is very easy to do with low amp hour battery capacity and does anyone manufacture Class Bs with AGMs to prevent that?

I've preached many times the liberating factor of using your Class B with no electrical worries transparently off-grid as if you are on shore power. I think that aspect is not appreciated until you have actually experienced it.

[wincrasher]

Yes, and shallow discharging only leads to one thing - longer battery life! Especially on lithiums. Testing has shown that only discharging 20-30% SOC can extend cycle life out into the 10's of thousands of cycles.

[gerrym51]

fit rv 59 KL yes KL

https://www.thefitrv.com/rv-reviews/...-travato-59kl/

[Technomadness]

Originally Posted by avanti

That's an interesting claim. I suppose you could make that case, but you would have to make a lot of dubious assumptions.

No I wouldn’t. And further, if you want to make an argument, make it. You’re the one making assumptions here and you totally fail to to even try to dig into the basis of my claim.

But asserting that it must be based on “dubious assumptions” is a smear— mainly meant to shut down debate and reject my claim out of hand.

Fact of the matter is, my claim is objective fact based on the stats.

The reason none of the Lithium badgers will actually make an argument is that the facts are not on your side.... so you just spread FUD.

There are very few situations where Lithium is not a better choice for house batteries: you’re poor and you need a low entry cost, or your rig is disposable and you don’t anticipate keeping it for more than a few years.


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[Technomadness]

Originally Posted by wincrasher

Yes, and shallow discharging only leads to one thing - longer battery life! Especially on lithiums. Testing has shown that only discharging 20-30% SOC can extend cycle life out into the 10's of thousands of cycles.

I think you are way underestimating how much longer the life is. Remember most stats are 1C or higher, yet most charging of a decent sized pack or via solar for even small packs, is well less than 1C.

Discharging, even at 1C has less reduction in lifetime than charging rates— and that’s more important than DoD.

All this focus on DoD is a holdover from the days of lead acid which couldn’t handle more than %50.

LFP has performed very well in vehicles for the past decade including very high C use, the RV application is super gentle.

We should expect significantly better performance than rated.


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[Davydd]

Actually there is data on RV lithium ion battery installations and expected life. Real data and not test lab data.

Living the Lithium Lifestyle – 3.5 Year Lithium RV Battery Update

After 3-1/2 years the authors stated that the batteries only had 75% of the stated capacity. Read the blog for details.

Advanced RV is always tweaking their systems. Last year I had an upgrade to my 800ah lithium ion system. Instead of staying fully charged all the time I now float from 90% to 99% SOC. In other words, when I reach 99% charging shuts down until SOC drops to 90%. That is tweaking for longer life. Batteries shut down at 20% SOC but I have set Autogen (auto starting the engine) at 40% SOC but have never dropped to that on our road trips. So I am theoretically keeping my batteries in a middle SOC range. The Autogen SOC is programmable. I don't know what the upper end is off hand but I've programmed it to 90% SOC in my impatience to see if Autogen actually worked. I have once turned Autogen off to see if the batteries actually shut down at 20% SOC. It did.

[wincrasher]

The EV manufactuers know that thermal control is the key to long life. They have high discharge and charge rates, on a daily basis, and manage to not have severe performance drop-offs. Tesla reports minor degradation of 10% or so in a few years. GM is reporting no degradation. GM keeps your use inside a more narrow band of SOC than Tesla does.

My own experience with the Volt this last year is making me optimistic about the durability of these batteries if you keep them in the proper temperature band. We all lament on here about freezing them, but few concerns voiced about cooking them. LiFEPO4's are a bit different than what's used in electric cars, as they don't get hot from discharging, but as Technomadia showed, you can cook them nonetheless.

[nebulight]

Originally Posted by Davydd

Actually there is data on RV lithium ion battery installations and expected life. Real data and not test lab data.

Living the Lithium Lifestyle – 3.5 Year Lithium RV Battery Update

After 3-1/2 years the authors stated that the batteries only had 75% of the stated capacity. Read the blog for details.

Advanced RV is always tweaking their systems. Last year I had an upgrade to my 800ah lithium ion system. Instead of staying fully charged all the time I now float from 90% to 99% SOC. In other words, when I reach 99% charging shuts down until SOC drops to 90%. That is tweaking for longer life. Batteries shut down at 20% SOC but I have set Autogen (auto starting the engine) at 40% SOC but have never dropped to that on our road trips. So I am theoretically keeping my batteries in a middle SOC range. The Autogen SOC is programmable. I don't know what the upper end is off hand but I've programmed it to 90% SOC in my impatience to see if Autogen actually worked. I have once turned Autogen off to see if the batteries actually shut down at 20% SOC. It did.

That is fine if the battery is in use, but for storage, most lithium chemistries like to be stored at 50-60% SOC. If you take notice, any electrical device that ships with a lithium battery is only ever 50% charged. Even large prismatic lifepo4 cells that ship from the factory are shipped at 50% SOC. Long term storage at high soc will degrade the batteries.

Originally Posted by wincrasher

The EV manufactuers know that thermal control is the key to long life. They have high discharge and charge rates, on a daily basis, and manage to not have severe performance drop-offs. Tesla reports minor degradation of 10% or so in a few years. GM is reporting no degradation. GM keeps your use inside a more narrow band of SOC than Tesla does.

My own experience with the Volt this last year is making me optimistic about the durability of these batteries if you keep them in the proper temperature band. [U]We all lament on here about freezing them, but few concerns voiced about cooking them. LiFEPO4's are a bit different than what's used in electric cars, as they don't get hot from discharging, but as Technomadia showed, you can cook them nonetheless[/B].

a lot of early DIY ev cars used lifepo4 and they do heat up. Using batteries on a van is what one boater calls fractional C. Most have healthy discharge rates of 1/2C. So davydd's van with 800AH, a healthy/normal discharge is 400 amps. We never get to the point where we get close to drawing that much current from the batteries. Even with my 400AH, 200 amps will never get drawn from my batteries. And that those lower C rates, they arne't producing that much heat.

Storage is always recommended in a cool place. If Technomadia spent a lot of time in 110F heat, that's just the outside temp and the battery box could have gotten much warmer.

Float is a highly debated topic. When I bought my van, the MPPT charger was set to float at 2 amps at 13.5V but has the ability to disable float and run in two stages (bulk and absorb). I disabled float and just set to 2 stage. I set my absorb time to 5 minutes and then the charge cycle is complete. There is no need to float these cells as the self discharge is so low that you'll never notice. Plus there is no harm in partial charge of a lifepo4 cell. And as I said before, the cells do not like to be at 100% SOC.

If the van is not in use, I discharge the cell down to 60%, then turn off the solar. Then a few days before I leave for a trip, I turn on my solar and I'm charged and ready for my trip.

[Davydd]

I agree batteries heat up in use. It varies from about 10-20 degrees F. above ambient air temperature when being charged. With minor draw since I am plugged in and have a draw of about 2-3 amps, they are practically ambient temperature in storage.

As for lithium ion batteries stored at 60% SOC that is questionable benefit at best in my practical experience over 3-1/2 years. If I stored outside as I did for two winters I stayed plugged into shore power so was always over 90% SOC. That kept my batteries above 41F at all times with resistant heating pads and since I have Trik-L-Start the lithium ion batteries kept my chassis battery charged. As for storage temperatures any comfortable temperature will do. So trying to stay at a 60% SOC would have been impractical.

[avanti]

I have seen hybrid cars whose manufacturers recommend 25% SOC for long-term storage. One of them went into detail about monitoring during storage and occasionally bringing it back up to 25%.

[Yellowhammer]

I have been looking at used Travatos and hoping to buy this summer. The new lithium system seems like a really good idea-but the cost of a new GL is out of my price range. How feasible and expensive is a lithium retrofit?

[warpig]

Originally Posted by Yellowhammer

I have been looking at used Travatos and hoping to buy this summer. The new lithium system seems like a really good idea-but the cost of a new GL is out of my price range. How feasible and expensive is a lithium retrofit?

http://www.classbforum.com/forums/f2...html#post71930

[BBQ]

.

Volta Key points

The Auto-Start

1. Each cycle will run for 60 min
2. @ high idle -- 1,600 RPM
3. Cycle stop triggers: SOC=90%, or fuel<1/4 tank
4. No cycle limits. The autostart will repeat the cycles until the fuel is down to 1/4 tank
5. The headlight will not come on during autostart cycles

https://www.youtube.com/watch?v=fudfEkPXlfc

[kite_rider]

Originally Posted by Yellowhammer

I have been looking at used Travatos and hoping to buy this summer. The new lithium system seems like a really good idea-but the cost of a new GL is out of my price range. How feasible and expensive is a lithium retrofit?

I suggested such a thing for a new van build in an older post. If you have an older Travato and want to get rid of the genny and replace it with a 2nd alternator and lithium batteries, the suggestion would be valid.

http://www.classbforum.com/forums/f2...uild-7217.html

In some other threads I've got some good new information about the voltage regulator that could be used with the retrofit system.

If this Volta system works out, then it makes me feel good about my original suggestion for this (52V NMC system). Would love to see the actual cells that Volta uses. They call it "Automotive NMC" in the marketing flyer..

[gregmchugh]

Based on the location of Volta in Holland, MI and the background of the management, I suspect they are using cells from one of the various cell manufacturers in Michigan (LG Chem, Johnson Controls, A123, ...) but maybe not...

https://voltapowersystems.com/company/

https://www.autoblog.com/2010/03/14/...in-holland-mi/