My Lithium Upgrade

[Treker20]

Thanks Rowie, Looks like you have a Roadtrek. I have a 2007 190P. Would like Battle Borns, and they would fit in the battery compartments, but then would have to install shunt in the inside like you did and I don't want to deal with bringing the battery cable through the floor. The Renogy smart batteries not only fit better, i can connect the the monitor to the smart batteries with only a low voltage cable and don't need a shunt. I have to see if I have room for the inverter changer in the area where the tripplite now is. I know there is no room there for the dc/dc changer. For now I may just disconnect the feed from the isolator. have your heard anything about the smart batteries and monitor?

[Treker20]

Wow, you have been jumping through a lot of hoops. I am still learning to walk through them.

[Treker20]

I am also looking into the heated batteries. We live in NC, but are traveling more and more and don't want to get with out battery power because of the cold. Battle Borns say you can change down to 26 F,(they did tests) Renogy does not give much info on that. Anyone have opinions on heated batteries?

[avanti]

Originally Posted by Treker20

I am also looking into the heated batteries. We live in NC, but are traveling more and more and don't want to get with out battery power because of the cold. Battle Borns say you can change down to 26 F,(they did tests) Renogy does not give much info on that. Anyone have opinions on heated batteries?

[OK, so I have been paying minimal attention to all the discussions about particular Li battery brands, due to lack of personal need. Since that is about to change, I guess it is time to get back in the saddle...]

WRT to heated batteries, it seems to me that the only setup that makes any sense is for the batteries to have internal heaters (or perhaps the ability to control external heat pads) AND the ability to automatically heat the battery using charging current until the battery is warm enough to be charged. As far as I can see, this completely takes the "cold charging" issue off the table and has no downside. I understand that this could be accomplished in other ways, but this one seems simple, foolproof, and invisible. Am I missing anything?

My impression is that this feature exists but is far from standard. Anybody know what brands behave this way?

[booster]

Originally Posted by avanti

[OK, so I have been paying minimal attention to all the discussions about particular Li battery brands, due to lack of personal need. Since that is about to change, I guess it is time to get back in the saddle...]

WRT to heated batteries, it seems to me that the only setup that makes any sense is for the batteries to have internal heaters (or perhaps the ability to control external heat blankets) AND the ability to automatically heat the battery using charging current until the battery is warm enough to be charged. As far as I can see, this completely takes the "cold charging" issue off the table and has no downside. Am I missing anything?

My impression is that this feature exists but is far from standard. Anybody know what brands behave this way?

I have had the same impressions about heating the batteries for a long time.



It would not be difficult to layout a system do the heating off charging power, even without going to a totally integrated control system. Using a small 110v powered supply would work to run the heaters until the batteries come online if you got shore power. A temporary connection to the engine charging, starting battery side of the vehicle wiring would handle it when no shore power. We aren't talking about a lot of power being needed for the heaters, at least based on the wattage we have seen for few heater installs that folks have posted. The heaters would run off the batteries and/or solar once they were back on line, of course, you have to make sure you have the bank capacity to do that in your sizing calculations if you are going to be in very cold weather and the batteries in a place the is cold even if the interior is warm from the furnace.

[avanti]

Originally Posted by booster

It would not be difficult to layout a system do the heating off charging power, even without going to a totally integrated control system. Using a small 110v powered supply would work to run the heaters until the batteries come online if you got shore power. A temporary connection to the engine charging, starting battery side of the vehicle wiring would handle it when no shore power. We aren't talking about a lot of power being needed for the heaters, at least based on the wattage we have seen for few heater installs that folks have posted. The heaters would run off the batteries and/or solar once they were back on line, of course, you have to make sure you have the bank capacity to do that in your sizing calculations if you are going to be in very cold weather and the batteries in a place the is cold even if the interior is warm from the furnace.

I don't understand the above. What I was trying to say is that it can be much simpler than that: The restriction (as I understand it) is on charging, not on use. So, we don't have to talk about shore power or "temporary connections" or solar. Nothing happens until I try to charge the batteries. I don't care where the charging current is coming from. The battery uses this power to heat itself until it is warm enough to charge, and then it switches to normal charging mode (which will itself continue to heat the battery, I assume). What could be simpler? I strongly believe that this is the job of the battery itself--I want basic safety reflexes to be in my spinal column, not in my brain.

Of course, there is also the issue of the battery being too-cold-to-store. That is a different matter. That WOULD require some external intelligence (something like "if it is really, really cold, heat up the battery compartment" or maybe "...start a charging cycle")

[rowiebowie]

Originally Posted by Treker20

I am also looking into the heated batteries. We live in NC, but are traveling more and more and don't want to get with out battery power because of the cold. Battle Borns say you can change down to 26 F,(they did tests) Renogy does not give much info on that. Anyone have opinions on heated batteries?

If you mount the batteries outside, definitely consider either self-heating batteries or some source of plug in heat. Since my batteries are mounted inside and I live in climate that (almost) never freezes, I don't have that concern. And on rare ocassions when camping in cold, like last month when overnight temps in Yellowstone dipped to 19 degrees, we are heating the interior because we are living in it.

I have a rare 2012 Airstream Avenue Suite on the Chevy Express chassis. Comparable in size and layout to your 190, but definitely not identical.

[booster]

Originally Posted by avanti

I don't understand the above. What I was trying to say is that it can be much simpler than that: The restriction (as I understand it) is on charging, not on use. So, we don't have to talk about shore power or "temporary connections" or solar. Nothing happens until I try to charge the batteries. I don't care where the charging current is coming from. The battery uses this power to heat itself until it is warm enough to charge, and then it switches to normal charging mode (which will itself continue to heat the battery, I assume). What could be simpler? I strongly believe that this is the job of the battery itself--I want basic safety reflexes to be in my spinal column, not in my brain.

Of course, there is also the issue of the battery being too-cold-to-store. That is a different matter. That WOULD require some external intelligence (something like "if it is really, really cold, heat up the battery compartment" or maybe "...start a charging cycle")

I would certainly think that could be done if you have enough capacity to do it and it isn't cold soaking out very quickly if you were trying to get ready to leave, you would also have furnace load, I think. That may have been what Roadtrek was trying to do with separate charge and discharge wiring they had in their models, but IIRC quit doing as they were failing (bad execution). It would be interesting to see just how many watt-hrs of heat are needed to raise the temp of the batteries from about 0*F to 33-35*F for various battery bank sizes and also what the capacity loss at those temps is for lithium. I think the ARV that davydd heated the batteries off themselves, but ran it through the 110v inverter to it and if they went offline that didn't work (which it could have at higher use than 12v heaters would be so don't know why they wouldn't do that). They said at the time that the only way was to get into warm place to warm the batteries, which made no sense at the time.


Of course, if you had a low temp cutoff for discharge, as in coming out of storage like you mention, and you don't remove the batteries you could be locked out. But the batteries should be removed then if no heaters and it is that cold. Same would be true if the batteries were low and then got cold so you wouldn't have the ability to heat them off themselves.


Personally, I think having both would be right way to go, as heating themselves makes sense in a warm van and in use as little heat would ever be needed unless they were underbody. I would, though, want to have at least one way to heat them from an outside source, with the engine charging being the one that covers all situations as long as the engine runs. Having the shore power option would be good so the batteries could be disconnected, but heated when stored with shore power.


Anybody know how Volta is doing it? Or Li3.


On edit: Here is an article that addresses capacity at lower temps and how much capacity it takes to heat the battery to usable from cold, but they didn't state the starting temperature, unfortunately. My guess it is the -20*C they talked about in the rest of the discussion.


https://shop.gwl.eu/blog/LiFePO4/FAQ...--at-20C-.html

[Davydd]

My first ARV in 2014 had 800ah of lithium LiFePO4 batteries that were under the van and heated by two 5 amp 12v electric heating pads sandwiched between the battery modules. They cycled on and off as necessary to maintain 41 deg. F. I could control and monitor this by the Silverleaf controller status and reports. Being 12v they were self heating off the batteries but used little power considering I had 800ah of battery. Very sophisticated.

My new ARV Class B the batteries of 576ah are under my bed inside the van. They too are heated and controlled by the Silverleaf but I haven’t inquired about how but underway the majority of the heat will come from the cabin heating to keep us warm and the battery space is ventilated. That seems to be the standard by upfitters when batteries are inside the cabin.

I haven’t inquired because I store inside a heated garage now set at 50 deg. and with shore power. My garage heater doesn’t even come on at 50 deg. because apparently all the surrounding garages are heated higher and my garage seems to be 70 deg. plus in the winter.

I believe when the Winnebago Revel came out they just said heat the cabin before charging the batteries to bring them up from freezing when underway. I don’t know if they had anything more sophisticated. I haven’t read anything about the other upfitters with lithium ion batteries either. They don’t seem to be concerned about the -4 deg. F damage.

ARV pretty much has abandoned the under the van batteries and have installed 48v Volta systems or 12v Lithiumwerks Valence batteries (my choice.) I had 12v Elite Power solutions in my previous ARV. This 2018 paper written by Fred Algren for ARV is still a pretty good source of information but is dated a little bit.

https://advanced-rv.com/wp-content/u...hite-Paper.pdf

[Treker20]

Booster, this link is to a white paper report that Battle Born did comparing discharge capacity between AGM and their Lithium batteries.

https://youtu.be/5gwmzDSkD7Y

[avanti]

I seem to be doing a terrible job communicating on this one. Let me be more concrete:

--I wake up one chilly morning and decide to go camping. My van has been sitting out completely turned off all night, so everything (including the batteries) are at ambient temperature, which is below freezing.

--So, what exactly do I have to do in order to get on with my trip? The answer I prefer is "nothing". I don't want to turn on any heaters. I don't want to turn off my charging system until the batteries are warm. I don't want to wait till my cabin is warm. So, what is the simplest and most robust way to accomplish this?

--What I am trying to say is that I should be able to simply start the engine and drive off. When I do this, the charging system will power up and start sending power to the battery. This is ok, even thought the battery is too cold to charge. Any proper BMS will prevent me from damaging my batteries in this case. But I want more: I want the BMS (built into the battery) to not just turn off the charging current, but rather to divert it to the battery's warming pads, so they warm up on their own accord, using the charger as the current source. The only consequence is a slightly longer charging time -- I don't need to understand anything.

I know that there is at least one battery with a built-in heater that behaves this way. Does anybody know which ones do and don't?

[Treker20]

Avanti, I am far from a battery expert, but I think the renogy heated battery will do that. It has a built in BMS that will shut down the charging at 0 C. It has a self heating mode that needs a constant charge of 4 amps and is activated at 41F. If i am understanding this right, heating will not start until battery charger come on.

[booster]

Originally Posted by Treker20

Booster, this link is to a white paper report that Battle Born did comparing discharge capacity between AGM and their Lithium batteries.

https://youtu.be/5gwmzDSkD7Y

I gave up on it as soon as they said they are using discharge voltage to determine the capacity comparison. Lithium always has lower voltage drop per amp of discharge rate so not surprising at all. They also said they will always get more energy, but the energy total, in amp hours or watt hours based on peukert will be skewed because the AGM will cut off earlier on higher amp draws. Heaters are very low amp draw so you would get more energy energy out increase from fast discharge to slow discharge than you would from lithium, but that wasn't the question either.


The only concern was how much capacity (energy) would you lose at the low use cutoff off -4*F compared to rated capacity. This would allow you to have a better idea of how long your battery bank could run the heaters to heat themselves if they were that cold. Of course it gets more complicated than that in reality as the batteries will be heating up over the testing, depending on how fast they transfer heat to the outside cold air.


I think it said the test went to 15-18*F it appears and used high amps so not really applicable.

[avanti]

What is an example of a situation in which I would want to use power from a battery to heat itself? I have a feeling I am missing something, but I don't see why I would want to do that. If I have power to charge I have power to heat. If I don't, I don't care if the battery is cold or not.

[booster]

Originally Posted by avanti

I seem to be doing a terrible job communicating on this one. Let me be more concrete:

--I wake up one chilly morning and decide to go camping. My van has been sitting out completely turned off all night, so everything (including the batteries) are at ambient temperature, which is below freezing.

--So, what exactly do I have to do in order to get on with my trip? The answer I prefer is "nothing". I don't want to turn on any heaters. I don't want to turn off my charging system until the batteries are warm. I don't want to wait till my cabin is warm. So, what is the simplest and most robust way to accomplish this?

--What I am trying to say is that I should be able to simply start the engine and drive off. When I do this, the charging system will power up and start sending power to the battery. This is ok, even thought the battery is too cold to charge. Any proper BMS will prevent me from damaging my batteries in this case. But I want more: I want the BMS (built into the battery) to not just turn off the charging current, but rather to divert it to the battery's warming pads, so they warm up on their own accord, using the charger as the current source. The only consequence is a slightly longer charging time -- I don't need to understand anything.

I know that there is at least one battery with a built-in heater that behaves this way. Does anybody know which ones do and don't?

I don't think there is any misunderstanding at all and what you want is doable by simply having the heaters connect from the chassis power side when the engine is running and thermostat on the batteries calling for heat. With a standalone alternator, it would have to be that way, I think, because if the batteries were in cold, no discharge, mode you wouldn't have a voltage reference for the standalone alternator. If the Transit will allow all your charging from the stock referenced system, that probably would be a really easy way to do it. That is pretty much what I was referring to and no input needed or lots of automation.



There is the question that I don't know if ever really got answered as to if the BMS should be used for no charging and/or low and high temp shutdowns. It seems the higher end systems are controlling separately and letting the BMS be suspenders with the belt system.

[avanti]

Originally Posted by booster

I don't think there is any misunderstanding at all and what you want is doable by simply having the heaters connect from the chassis power side when the engine is running and thermostat on the batteries calling for heat. With a standalone alternator, it would have to be that way, I think, because if the batteries were in cold, no discharge, mode you wouldn't have a voltage reference for the standalone alternator. If the Transit will allow all your charging from the stock referenced system, that probably would be a really easy way to do it.

OK, yes, your solution answers my need and isn't very complex. I guess I still think that the feature belongs inside the battery itself, at least if we are talking about a battery with a built-in heater, which I think I also prefer.

[rowiebowie]

Originally Posted by avanti

OK, yes, your solution answers my need and isn't very complex. I guess I still think that the feature belongs inside the battery itself, at least if we are talking about a battery with a built-in heater, which I think I also prefer.

I was previously suspicious of batteries with built-in heaters thinking the heaters may draw too much current and be counter-productive. But I'm less so now after the experience below when I was finally able to use my tank heaters (turns out they don't come on until temps are at or near freezing, so I was never able to test them before).

We recently camped in Yellowstone's Madison campground without hook ups and only 200Ah of lithium batteries. We arrived with batteries full and gray/black/macerator winterized with rv antifreeze, and overnight temps predicted to be in the high teens farenheit (which turned out to be 19 the first night and 21 degrees the second night).

I flipped on the tank heaters for the first time and found out (if I recall correctly) that they collectively only used about 9-10 amps. I only turned on the gray/black tank heaters briefly to test their draw. I did, however, leave the fresh tank heater on all night which only drew 4-5 amps.

This draw was much less than I anticipated and I anticipate internal battery heaters to draw even less. We still had a bit over 50% battery charge in the morning after using lights, furnace, and a couple of hours of Inverter that included brief Microwave use.

So, as long as self-heating batteries are not worse power hogs than my tank heaters, I would expect an easy two to three days of self-heating before you'd need to charge (assuming no other power usage). I haven't looked, but the battery makers show reveal the heating draw in their specs.

[themexicandoctor]

Did you know that Lifeline, the World's PREMIER AGM Battery Manufacturer, here in the USA, now makes two sizes of Lithium Batteries, a 24 & 27?

On the "Lifeline is Obsolete?", a completely erroneous heading, there is a discussion.

I don't know if they have the heating g elements you require but I do know, they are technically superior to anything Renogy or Battleborn make.

They have to be, they have the Lifeline name in them.

Even

[Treker20]

I have found out some info on the renogy. Attached is a video that a reviewer made of the battery,
Basically, the heat function can be activated when temperature drops below 41 degrees. But it will not start to heat until the battery is being charged. so no drain on battery.
Here is the link to the video, he goes into a lot of detail since renogy gave him the battery to try, but he talks about the heating about 8:30 into it.

https://www.youtube.com/watch?v=c8LcrYfFnbM

[Treker20]

Booster, this goes to show a little bit of knowledge can be dangerous. to me it looked like a great answer.