Converting to Lithium

[Jon Vermilye]

Originally Posted by Steve Hammel

That's long enough to heat your coffee water.

Actually, my coffee water comes from a 600 watt 5 cup drip coffee maker. I usually make 3-4 cups & fill my mug twice. I haven't yet rewarmed it in the microwave since I usually drink 2 mugs full reading forums & blogs.

It will be long enough to cook a frozen Jimmy Dean sausage, cheese & egg, although I would love to find something better - they sure are not up to even fast food versions.

[Steve Hammel]

Lol, I stopped at a tiny seasonal cafe in Nine Mile Falls Washington and their featured delicacy was Jimmy Dean frozen breakfast sandwiches. They did microwave them for you.

[Jon Vermilye]

Discovered a minor problem - tried to run the power tongue jack - no go. Escape ties into the charge line for power for the tongue jack. The DC to DC converter I added to the charge line does not pass the converter voltage backwards through it, so no DC at the jack. I'll have to run a new line form the converter to the jack.

[Steve Hammel]

Any new updates? Also, if you don't mind me asking, what are you using for a battery monitor and charge controller for your solar?

[Jon Vermilye]

No updates - the system is up & running. The only thing I can't check is the tow vehicle charge line since the F 150 doesn't seem to be generating anything on pin 4.

I'm using a Victron Smart Solar 100/30 for the solar controller, and the Victron 712 for the battery monitor. Both send the current status to my phone over Bluetooth, keep a history of data (the solar for at least 15 days; as long as I've had it running, and are working as expected.

Again, I have no way of checking the Victron Energy Orion-Tr 12/12-9A (9 amp DC to DC converter) in the charge line until the truck is fixed. Earliest appointment is July 17th!

The whole project is documented at Converting to Lithium.

[Jon Vermilye]

Well, I just got back from an oil change at Ford, and tried to purchase another 25 amp fuse to replace the one in slot #30 (the trailer charge fuse). After using the VIN # to look up the replacement, the parts guy came out with a shorter, 30 amp fuse, insisted that it was what should have been in slot #30.

Sooo, I pulled what looked like a good 25 amp fuse (it wasn't), replaced it with what looked like the wrong size 30 amp fuse, and the charge line is working again. I'm not worried about the extra 5 amps with the new fuse size since I've never seen more than 9 amps from the truck. Who knows which is correct?

One less thing to get fixed on July 17th. Off topic, but interesting, at least to me - All that is wrong with the truck is an intermittent whine coming out of the entertainment console. Not the speakers, but directly from the console. It has happened 4 times over the last year, and when it starts, nothing shuts it off, including pulling all the fuses related to audio. Shutting off the truck doesn't kill it - it goes all night! It does stop while you are under a bridge, so I suspect it has something to do with the XM radio. After a couple of hours or days, it goes away. I recorded the whine, but I don't know how that is going to help.

The Victron DC to DC converter works as expected. 14.4V going into the batteries ,with less than 13V coming out of the truck.

[Steve Hammel]

Good deal, I'm sure now that you have a "Ford" instead of your Toyota you'll experience lots of little nuisance issues. Scary to have the wrong size and amperage fuse in that slot. Makes you wonder what the heck else is wrong.

[CarlD]

Good to hear you got everything working. You will probably measure about 11-13 amps from the truck when you get 9 amps out of the converter.


These converters would certainly take the guessing out of trying to run a gas absorption fridge on vehicle power while driving as long as the feed line from the TV can handle 13 amps, the line loss drops out of the equation.

[Raspy]

Jon,

Thanks for your excellent writeup "changing from Lead acid to lithium". This is a project I've been considering, and want to eventually do, for all the reasons you mentioned. The charging and management systems have been a dark area that I haven't got sorted out yet. Very helpful.

[ZachO]

I know it's off topic but I'm online reading threads...It's probably not exciting to you and I've brought this up before, but as a NY native who hasn't even set foot in the state in well over 10 years, it's still sort of exciting for me to see people from close to where I grew up. I'm a Fayetteville/Manlius native, currently house sitting for a Skaneateles native in the Centennial Valley, MT.

That's pretty exciting about that battery though! I'm far enough away from retirement that I'm always hesitant to put too much work or money into my trailer, since there's really no telling if I'll even own it in 2-5 years, but this is all stuff I'm keeping in the back of my mind for when I really settle in to something long-term.

[CarlD]

If you figure what you really want it is worth it to put the money into great quality now because you'll have it for a very long time.

[Jon Vermilye]

A real world update on the new batteries:

For anyone interested, I can give some user data on a combination of 480 watts of solar & a pair of 100 amp hour Battleborn lithium batteries here at Quartzsite, AZ. The data was collected by the Victron bluetooth readouts for both the solar controller & the battery monitor. While it is obviously conditioned on the solar conditions, which, of course, are variable, it might give users some "real world" idea of what they can expect from a system. I consider myself a "heavy" user of power - typically 50 amp hours per day. I usually make a pot of coffee, often microwave breakfast or dinner, use an electric toaster, and set the furnace at 60°F (it has been cooler than usual this winter)

I have 2 160 watt rooftop panels tilted for the correct angle for Phoenix, AZ for mid January. The trailer is aimed a bit west of due south. I also have a 160 watt portable panel that I shift 2-3 times a day to "follow" the sun. Batteries are charged through a Victron 100/30 MPPT solar controller. Since lithium batteries stay in the bulk mode until 95% filled, and only spend a few minutes in the absorption mode, unlike lead acid batteries, the full output of the panels is available at the batteries until they are filled.

While so far this winter I have not depleted the batteries to the point where I had to run a generator, after a 3 day stretch without enough sun to put the controller into the float mode, and being down 54 amp hours, I ran a small propane generator for 4 hours to bring the batteries back to full (and do a monthly generator run). This was probably not necessary, although the prediction was for another 3 days of heavy clouds. The lithium batteries can be safely drawn down to 10%, so I could have gone without the generator, but I needed to run it anyway, and I tend to be a bit conservative.

This has been the coolest & most cloud covered winter I've stayed at the Q over the last 4 years so the results would probably be better under more usual conditions. This is for December 9 - December 31. (21 days). Today (the 31st) is obviously not finished, but as of 11:00 AM I'm putting 91 watts into the trailer, had a peak of 195 watts, and collected a total of 250 watt hours (it is cloudy). Still down 49 amp hours for the day (I did not reach float yesterday).

Peak solar wattage - 423 watts. Minimum solar wattage - 42 watts. Peak KW hours collected - 1.49KWh. Lowest watt hours collected - 140 watt hours. # of days the controller never received enough sun to get out of the bulk mode - 7.

# of days the batteries reached full - 15. Largest discharge - -72 amp hours.

The image below is the December solar output. White = Bulk, Gray = Absorption & Light Blue = Float.

[David B.]

Thanks Jon. When our Lifeline D AGM batteries die, I plan to model our solar after yours.
Dave & Paula

[Stephen_Albers]

Have you considered your temperature operating range requirement?

Stephen

[Air Doug]

Originally Posted by Stephen_Albers

Have you considered your temperature operating range requirement?

Stephen

The Battle Born batteries have a battery management system (BMS) that prevents charging if the battery is too cold (25 degrees F or colder) and prevents charging or discharging if too hot (135 degrees F or hotter). In my Lil Snoozy application the batteries are internal to the trailer so it is pretty easy to keep them above 25 degrees. And 135 is way above my operating range.

[Stephen_Albers]

Good thinking. But you should also consider cold storage when your trailer is not being used. Make sure cold storage temperatures don't damage the battery from freezing unless you plan indoor storage. Further, how do you start up from below 25F, which is common in winter?

[Jon Vermilye]

Since I live in upstate NY, I talked with Battleborn about low temperature storage. Their answer - don't charge with the battery temperature under 32°F, don't draw current under 0°F, both of which are prevented by the BMS built into the battery. For long term, non use, store the batteries at 80% full, and if the temperature is expected to go below -4°F, pull the batteries and store them above freezing.

My solution is to spend winter in Arizona. Even if it does get cold, my batteries are in the trailer, so as long as I'm using it, freezing temperatures are not a problem.

[Air Doug]

Originally Posted by CarlD

I read your blog and everything looks ok except that the Battleborn LFP should be charged at 14.6 volts. The BMS will disconnect just below that value when fully charged.


Also, if you intend to charge the battery from your tow vehicle you will need a DC-DC converter. I am using a 9 amp isolated victron model. I see Renogy has a 20 amp charger which might be suitable. Set it to the same voltage as your Progressive Dynamics power supply.

I will offer a slightly different perspective and a caution.

I have read some statements that charging at lower voltages increases battery life. Battle Born recommends 14.4 volts on their website. If I had done my research better, I would have ordered the PD converter/charger set to 14.4 instead of 14.6. The Victron isolated DC/DC converter can be adjusted with a tiny screw and I set mine at 14.2 volts.

Regarding charging from the tow vehicle at 20 amps, that's 240 watts at 12v. Now I may get in trouble for giving opinions that I don't know as much about as I should, but here goes. When I looked at the length of wire from the vehicle battery to the trailer battery, it was ~15 feet in the 4Runner and ~20' in the trailer, for a total of ~35'. I believe the vehicle and trailer wire is 12ga. Blue Sea shows an ampacity for 12 ga wire of 20a up to 30 feet with a 10% voltage drop. So 20 amp charging in my application would be pushing the limits, I think. And can the vehicle alternator handle 20a long-term? The power outlets are limited in the 4Runner to 120 watts maximum total for all outlets combined. I have found 9 amps to be just fine for what I do.

[Air Doug]

Originally Posted by Stephen_Albers

...how do you start up from below 25F, which is common in winter?

Discharge below 25F down to 0 is fine. I don't camp in temperatures below the teens.

[Jon Vermilye]

I agree with Douglas. Again, talking with Battleborn, it is important that you charge at at least 14.4V for the absorption phase. That is when the battery balancing system does its thing. While you can charge up to 14.6V, they prefer 14.4V.

As to charging via tow vehicle, I have had no problems running a Victron 9 amp DC to DC controller set at 14.4V. I could go with a higher current version, but with my typical 4 hour drive between campsites, @ 9 amps I'm putting 36 amp hours into the batteries. With 320 watts of rooftop solar, between the two sources, I have never ended up at a campsite with less than 100% full batteries.