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Lithium ion phosphate battery


 

Hi all.? I was thinking about swapping out my AGM battery in my Aliner Classic for a lithium one.? The biggest concern I have is the possibility of burning out the alternator in my tow vehicle if the li ion is discharged when towing.? I have read that a DC-DC charger would solve this potential problem, but was wondering if anyone has installed a single 100 ah li ion battery without any other devices.? And if they did, were there any problems.? Thanks

?? Bob


 

I hadn't installed any extra devices from the tow vehicle & ran a lithium battery for several years without issue, the wire size to the 7 way connector won't allow you to draw too much from the tow vehicle (too much line loss). But your vehicle may not charge your lithium all the way and might even discharge it a little while towing (approx 90% charge).? The higher lithium battery voltage may prevent your alternator from charging? until the voltage on the lipo4 battery drops a little, some people tow with headlights on to keep the alternator engaged. (if you have a newer smart alternator)

But in general no issues.
Happy Camping
Dan S

Last year I added a small cable from my roof mounted solar (before I just hooked up when parked) , so I solar charge while driving now also


On Thu, Feb 29, 2024 at 5:20 PM, BobF
<rf771918@...> wrote:
Hi all.? I was thinking about swapping out my AGM battery in my Aliner Classic for a lithium one.? The biggest concern I have is the possibility of burning out the alternator in my tow vehicle if the li ion is discharged when towing.? I have read that a DC-DC charger would solve this potential problem, but was wondering if anyone has installed a single 100 ah li ion battery without any other devices.? And if they did, were there any problems.? Thanks

?? Bob


 

Years ago I had my vehicle battery go dead while camping in a remote area of Michigan’s UP. I left an inverter plugged into a constant 12v outlet. With our Aliner Classic we now often?camp in remote areas without cell service. I installed solar panels and controller to change the camper batteries while camping and on the road. The is no electrical connection, other than lights, between the camper and TV. I would not risk being stranded for the sake of a couple hundred dollars saved by charging from the TV. Modern batteries seem to fail without much warning. Note: I am a bit paranoid about that so I found space under the hood to mount an extra battery totally disconnected from anything that is ready to be used for a jump start if needed. Just my 2 cents.
JoeS


 

I recently replaced my original deep cycle lead-acid marine battery for a 100AH Lithium Iron Phosphate battery. As others have said, the "full charge" voltage of the LiFePo battery is higher than lead-acid, about 14.4-14.6V. The car cannot over charge it. I upgraded the DC converter in my 2008 Aliner to a newer one that had a setting for the lithium battery. I also added a solar panel and charge controller, as well as a cutoff switch for the shore power charger. This last bit was to insure I am not constantly "floating" the lithium battery at 14.6v while I am connected to shore power for extended periods. One of the main reasons I wanted to switch to a higher capacity battery was so that I am not completely draining it while driving long distances while the fridge is running on 12 volts. The fridge draws about 10amps while on DC. I have found that with the tow vehicle running, about 5 amps is being supplied from the tow vehicle. This halves the amount needed from the camper battery. The solar panel can add an additional 2-3 amps while driving on a sunny day. I can monitor the charge/discharge current and battery voltage via Bluetooth while driving. Getting ready for a 5000 mile road trip for the eclipse and I expect this upgrade to help a lot on future trips as well.


 

Thanks Dan, this was the info I was looking for. The videos on YouTube showing a smoking alternator were a little scary. But, they only showed the alternator connected directly to the lithium battery.? I was wondering, though, if you have towed after camping with the lithium battery almost completely discharged.? According to the info out there, this is when you could fry the alternator.


 

Thanks to all who responded.? I have a solar panel permanently mounted on my Aliner which helps charge the battery while towing and have never had any problems draining the battery with the fridge running on 12 volts.? My concern is that sometimes when I am camping in the deep woods I do not receive enough sun on my solar panel to charge the battery so when I leave the campsite my agm battery is discharged.? If the same thing happened with a lithium battery, I was concerned that this might cause a problem with my alternator while towing home.


 

Be careful here.? Sure some people drop in a lithium battery and have no major issues.? But others do have issues.? Which category will your setup fall into?? You have to take into account make, model, and year of tow vehicle, brand of lithium battery and max charge rate, how it was wired (direct or through the bargman cable), how many batteries are being charged, and how deeply discharged the lithium battery was when the test was started (some never deeply discharge the battery).

With just one battery and charging through the bargman cable, I doubt, but can't guarantee, you won't damage your alternator.? You would probably blow the typical 30 amp fuse on the bargman power wire first.?

But you have other more likely problems you may need to deal with:

Some vehicles won't charge a lithium trailer battery while towing, and instead drain it.? I know my 4Runner has a bad problem in this area.? The dc dc charger also fixes this.

Some converters have an equalization mode that may wreck a lithium battery.

Some converters are reluctant to go to 14.4 volts, and do a lousy job of charging a lithium battery.? That gives you less battery power, and also shortens the life of the lithium battery.

If you get a new converter, get a 50 amp one.? That will shorten charging times, which is nice when using a generator.


 

?We installed a 100ah Battle Born LiFePO4 battery on our Chalet LTW back in 2016. It is definitely superior to lead acid batteries of all types, but we had an added issue with it when we replaced our Volvo tow vehicle with a plug-in hybrid Audi in 2017. Our Audi does not have an alternator, so all power from the tow vehicle comes from the 12V accessory battery only. The problem was that it only sends a max of 12.6V, not enough to keep our 3 cu.ft. refrigerator operating while being towed. The 12V accessory battery is recharged while driving via the PHEV main battery, but not at a high enough voltage, so we discovered an alternative solution. We installed a 175W Renogy thin flexible solar panel on the front of the roof of our Chalet, bolting it securely and used 50 year warranty 100% silicone caulk to prevent any leaks. The panel is wired through a MPPT charge controller, which will charge the LiFePO4 as high as 14.5V, something a standard charge controller will not do for lead acid batteries, which is why a specific controller must be used for Lithium batteries. The controller and battery are both encased in lockable steel boxes to prevent theft. We now have zero issues with maintain our refrigerator during towing, except at night, of course. We also do not have to pull out our folding 120W or Renogy aluminum framed 100W portable panels when we camp, uncles we are under trees and need to position our extra panels further from the trailer. True, this was not a simple solution, but we are never short on power now, plus the charge controller is the best and safest for LiFePO4, which is the best and safest Lithium chemistry.

D Link


 

It is true that the standard converter in a liners are not setup for lithium. (Maybe the new aliens are?)

So you can go one of two routes, change the converter, or bypass the charger on the converter and add a new charger for shore power.?

Some one mentioned adding a 50amp charger, I would be very careful about using a 50amp charger in your aliner - this would require new wiring and fusing to the battery, the factory installed wiring and fusing is setup for 30amp max.

Back to the original question, your tow vehicle through a 7 pin harness probably won't charge a lipo4 battery completely but it won't hurt it either.

If you charge at campsite via shore power or solar with the proper charger - should be no issues

Happy Camping
Dan S


On Fri, Mar 1, 2024 at 8:31 AM, D Link via groups.io
<d_linkeg@...> wrote:
We installed a 100ah Battle Born LiFePO4 battery on our Chalet LTW back in 2016. It is definitely superior to lead acid batteries of all types, but we had an added issue with it when we replaced our Volvo tow vehicle with a plug-in hybrid Audi in 2017. Our Audi does not have an alternator, so all power from the tow vehicle comes from the 12V accessory battery only. The problem was that it only sends a max of 12.6V, not enough to keep our 3 cu.ft. refrigerator operating while being towed. The 12V accessory battery is recharged while driving via the PHEV main battery, but not at a high enough voltage, so we discovered an alternative solution. We installed a 175W Renogy thin flexible solar panel on the front of the roof of our Chalet, bolting it securely and used 50 year warranty 100% silicone caulk to prevent any leaks. The panel is wired through a MPPT charge controller, which will charge the LiFePO4 as high as 14.5V, something a standard charge controller will not do for lead acid batteries, which is why a specific controller must be used for Lithium batteries. The controller and battery are both encased in lockable steel boxes to prevent theft. We now have zero issues with maintain our refrigerator during towing, except at night, of course. We also do not have to pull out our folding 120W or Renogy aluminum framed 100W portable panels when we camp, uncles we are under trees and need to position our extra panels further from the trailer. True, this was not a simple solution, but we are never short on power now, plus the charge controller is the best and safest for LiFePO4, which is the best and safest Lithium chemistry.

D Link






 

I just did an on-line chat with Renogy re my situation. The reply was that they would not recommend installing a lithium battery in the camper without a DC-DC charger.? My original avoidance of wanting to do this is that some of these converters require a wire connected to the tow vehicle ignition switch and I did not want to run an additional wire thru my vehicle to do this.? However, I found out that Victron makes a charger that does not require this.? So, I guess my next question would be has anyone used this type of charger and how and where did you install it?


 

I went for overkill on the solar with 2-175 watt Renogy flexible panels and a MPPT controller. The panels fit perfectly on the front dormer with the controller mounted in a weathertight box next to the batteries. It will charge the 2 golf cart batteries just a little on a 4 hour road trip on a rainy day. I run the fridge on propane so the only battery drains on the road are the fridge fan, rear camera, brakes and safety sensors. Like I said in my earlier post, I would not risk the reliability of my TV for anything.


 

If your bargman power wire isnt shut off by the tow vehicle when the engine is off, you can't use the victron charger that doesn't have the additional wire option, because there no way to turn off the dc dc charger.? If the bargman power wire is shut off when the tow vehicle engine ships off, you just wire the bargman power wire into the main input of the dc dc charger, and also as the additional wire option.


On Fri, Mar 1, 2024 at 10:15 AM, BobF wrote:
I just did an on-line chat with Renogy re my situation. The reply was that they would not recommend installing a lithium battery in the camper without a DC-DC charger.? My original avoidance of wanting to do this is that some of these converters require a wire connected to the tow vehicle ignition switch and I did not want to run an additional wire thru my vehicle to do this.? However, I found out that Victron makes a charger that does not require this.? So, I guess my next question would be has anyone used this type of charger and how and where did you install it?


 

I installed an SOK 206Ah LiFePo4 battery in 2022.? As mentioned above, the converter does not charge a lithium battery properly.? My battery is still hooked up to the converter, but I have 400 watts of solar on my Dormer and a victron mppt CC? that do the charging. The only time I hook up to shore power is to test how much that would put into the battery. I monitor this on the Victron shunt I have installed in the system. I recommend these shunts as they will tell you truly your battery state of charge.? If I do connect to shore power on a sunny day, my victron system typically puts an additional 40 to 60 watt hours into the battery above what the charge controller puts in.
Lead acid batteries are at 100% when the voltage is 12.8 or higher. A typical good quality mppt charge controller will charge your battery at 3 stages each having their own voltage. The absorption phase, (100%), is when you will see the voltages up at 14.4 or 14.6 depending upon the settings in the charge controller and what the battery manufacturer recommend for this setting.? First stage bulk charging and last stage float charging are generally in the area of 13.5 & 13:8 volts respectively.
Again as above most likely there will be no charging going forward or backwards through your seven pin connection, in my experience.
I have a friend who ran a number 10 wire from the battery to the seven pin connection to run his fridge on DC in his ranger 12. There was a lot of voltage drop over the length of his TV back to the seven pin and failed to run his refrigerator properly.??


 

Towing your trailer while the propane is burning to operate the refrigerator is not legal in many states, so please investigate carefully before you do this. Also, propane has a habit of blowing out while being towed, which can cause gas buildup inside the trailer. This could be a bomb if a spark ignites it.


 

Actually, it is legal to tow with propane on in all states.? Its only illegal in some tunnels and on ferries. I saw a survey that said 70% of RVs tow with propane on, because its so difficult to get the fridge running on DC properly.? It may be bad for us, but its a lot worse for the big RVs which have another 20 feet of wire to get to the fridge, and have bigger fridges that draw more power.

The government also doesn't make any attempt to fix the problem.? They could require thicker power wires running through the tow vehicle, and in the bargman cable.? But they don't, and you can't even buy a bargman cable with a power wire thicker than 10 gauge.? If they had 4 gauge wire in the vehicle and the bargman, you could then easily install a 20 amp dc dc charger in the trailer and the problem would be solved.? Trailers would then probably come with a dc dc charger installed by the trailer manufacturer.

They also don't regulate how the propane excess flow shutoff works either.? It also has gotten less effective in the last 5 years too.? It used to be that when the propane shutoff engages, the amount of propane coming out would be only enough to barely light a stove burner.? But when I replaced my propane pigtails last time, I noticed that after the shutoff engaged, the burner still burned as if on its highest setting.?

Its also much more difficult to get the excess flow shutoff to engage.? My old pigtails would engage the shutoff if the flow was at the max output by the regulator.? My new pigtails would not shutoff with max regulator output.? So the excess flow shutoff now only works if you cut the propane line between the tank and the regulator -- in other words, if the pigtail is cut.??

I found this out when I tried to find pigtails with a lower max flow shutoff.? I called around asking for better pigtails, and I finally got connected to a guy that knew about propane, and he said nope, they don't shutoff at the max flow supplied by the typical regulator.? Again, this is another area where the government could impose standards that make the excess flow engage with less than max flow put out by the regulator, but they don't.??

I also looked into putting in thicker wires, and tried to find waterproof connectors, so I could disconnect these thicker wires when the trailer wasn't hitched.? I could not find anybody that had waterproof connectors.? One guy had a picture of his setup on his truck, and was using Anderson connectors that are not waterproof.? The connection point was behind the rear wheel, where it would get blasted from tire spray in rain.? Not very impressive.? The fact that I couldn't find good examples of this must mean very few are doing it.

So I'm towing with the fridge running on propane, like most others.


On Sat, Mar 2, 2024 at 01:44 AM, D Link wrote:
Towing your trailer while the propane is burning to operate the refrigerator is not legal in many states, so please investigate carefully before you do this. Also, propane has a habit of blowing out while being towed, which can cause gas buildup inside the trailer. This could be a bomb if a spark ignites it.


 

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I’ve mentioned this before, so let me be clear:? with the Renogy DC-DC converter/charger, the trigger wire does NOT need to be connected via a separate wire to the TV ignition!? Just wire it to the positive incoming wire from the TV, and if you don’t already have one, install a TV mounted cut-off relay in the positive wire coming from the TV battery, that cuts off the current flow from TV battery/alternator to the camper when the TV engine is not running.? Every TV should have a cut-off relay so the TV battery can’t be drained when the rig is parked with TV engine off.?

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I’ve wired my Renogy 20 amp DC-DC converter/charger this way for years with no problem!

?

Dave

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...? My original avoidance of wanting to do this is that some of these converters require a wire connected to the tow vehicle ignition switch and I did not want to run an additional wire thru my vehicle to do this.?


 

Dave, this sounds like a great idea, but just wondering what you wired the relay to so it would turn off with the engine.? I imagine it would be necessary to find a circuit that is only hot with the ignition on. Did you then not connect the ignition wire at all on the charger?? From what I read on the Renogy web site the charger will not work unless the ignition wire is connected.


 

Bob, I think the point that's being missed here is that one wire can be connected to 2 locations.? So if the power wire from the TV to the trailer shuts off when the TV engine shuts off, you can splice two wires on the end of the power wire, and connect one of those to the ignition terminal, and the other to the input power of the dc charger.? Does that make this conversation make sense?

Be aware that you have two options for how you install the dc charger.? One option is to connect it to the existing power wire in the bargman cable.? In this configuration you have to run the the 20 amp dc charger in 1/2 power mode, because the bargman cable can't handle full power.

The other alternative is to run separate fatter wires for power from the TV to the trailer, and then you can run the dc charger to output the full 20 amps.

The first option is the easy one to install.? Your bargman power wire most likely already is setup to shut off power when thd TV engine shuts off.? Provided that's true, you cut the + and - power wires coming out of your bargman cable in your trailer, fasten 3 extension wires to the + wire on the vehicle side, then fasten one of those + extensions to the power input on the dc charger, another to the ignition terminal, and another to the current limiting terminal to make the charger run at half power.? Then also connect the - power wire to the - charger input.? Then the other ends of the cut wire fasten to the outputs of the dc charger.


On Sat, Mar 2, 2024 at 08:20 AM, BobF wrote:
Dave, this sounds like a great idea, but just wondering what you wired the relay to so it would turn off with the engine.? I imagine it would be necessary to find a circuit that is only hot with the ignition on. Did you then not connect the ignition wire at all on the charger?? From what I read on the Renogy web site the charger will not work unless the ignition wire is connected.


 

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I ran into this same dilemma when I installed my DC-DC converter/charger, so I ran 8awg wiring from the TV start battery positive (AND negative too), through a 50 amp fuse and an ignition switched cut-off relay (a 12 volt boiler relay with nice big contacts mounted under the driver’s seat) to the Bargman receptacle on my TV, then from the camper’s Bargman plug to the DC-DC unit. This involves cramming two thick wires into the Bargman receptacle and plug, but it can be done and results in a relatively weatherproof connection (as much as the Bargman assembly ever provides…)

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This solution has been working for years.

?

Dave

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I also looked into putting in thicker wires, and tried to find waterproof connectors, so I could disconnect these thicker wires when the trailer wasn't hitched.? I could not find anybody that had waterproof connectors.?


 

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Every TV has at least one circuit that is only hot when the ignition is on.? You can find these circuits within the fuse boxes that all modern vehicles have.? Then just tap onto one of these switched voltage sources to power your cut-off relay.? Then the relay cuts-off the current flow from your TV start battery to your DC-DC converter/charger whenever your TV ignition is off.

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The DC-DC exciter connection that ordinarily goes to the very same ignition-on source in your TV is then just jumpered to the positive wire coming from the TV via its cut-off relay using a short length of 14 awg wire. No splicing is required, just a jumper from the exciter terminal on the DC-DC to the positive input terminal on the DC-DC. Saves an extra wire from the camper to the TV.

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BTW, I ran 8awg wiring from TV to camper so that there would be minimal line loss when charging the camper battery via the DC-DC at up to 20 amps.

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Dave

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?

Dave, this sounds like a great idea, but just wondering what you wired the relay to so it would turn off with the engine.? I imagine it would be necessary to find a circuit that is only hot with the ignition on. Did you then not connect the ignition wire at all on the charger?? From what I read on the Renogy web site the charger will not work unless the ignition wire is connected.