Pro-Rig V2.0 - Home Built Compact Composite Pop-up

[CoyoteThistle]

Worse....I’m getting these BS pop ups instead of the pictures when I clicked on them!
Looks like his pictures page somehow got hijacked.
So.....Don’t open his pictures links!!!

This stuff kinda pisses me off when people post blind links (or download files) here instead of putting their original info right in their posts. Now I’m gonna have to run a virus scan and cache cleaner. ****!

Looks like Photobucket is down for lots of people or everyone. No need to freak out man.

Lots of us spend a fair amount of time posting here to help other builders out or entertain fellow camper nerds - if my way of posting pisses you off, plenty of other places to go on the web

 

[AbleGuy]

Well, you might note I said ‘kinda’ pisses me off, so not quite freakin out yet?

anyway


(Cat actually kinds looks like me, or visa versa)

 

[CoyoteThistle]

Okay, time to get the Maxxair fan up and running again. They sent me a new board. No instructions but pretty straight forward replacement. A little searching on these fans turned up two known weaknesses that will apparently fry the board: 1) moisture and 2) highish voltage. The small camper can get moist and our Lithium batteries are usually at a higher voltage than typical lead acid. I probably just got a lame board, but I decided to try to cover these two issues just in case.

First issue addressed by brushing on a conformal coating.


That's the board after a light coat with that little brush. We'll see...

Second issue addressed by adding a little voltage regulator to the power supply line.


$10 Amazon thing. Power and ground in and out and a little voltage adjuster. Mounted it in with the house battery BMS.


Set it to 12.3v. Put it all back together and all seems to be working. Will report back...

Next project is thermostat controlled battery heaters to keep the LiFePO4 from getting too cold. Details to follow...

 

[java]

My maxxfan has been being grumpy too. I need to coat my board as well.

Sent from my SM-G973U using Tapatalk

 

[Anton2k3]

Okay, time to get the Maxxair fan up and running again. They sent me a new board. No instructions but pretty straight forward replacement. A little searching on these fans turned up two known weaknesses that will apparently fry the board: 1) moisture and 2) highish voltage. The small camper can get moist and our Lithium batteries are usually at a higher voltage than typical lead acid. I probably just got a lame board, but I decided to try to cover these two issues just in case.

First issue addressed by brushing on a conformal coating.


That's the board after a light coat with that little brush. We'll see...

Second issue addressed by adding a little voltage regulator to the power supply line.


$10 Amazon thing. Power and ground in and out and a little voltage adjuster. Mounted it in with the house battery BMS.


Set it to 12.3v. Put it all back together and all seems to be working. Will report back...

Next project is thermostat controlled battery heaters to keep the LiFePO4 from getting too cold. Details to follow...

I used the same voltage regulator to permanently dim my bedroom light, works well.
Interested to see what your heating solution is. Mine (although not plumbed in yet), is a spur off the diesel water heater coolant line with a thermostatic valve in the battery space. Problem is it will only work when the heater is on. Need a secondary for when it’s off (or make the thermo valve start the heater up).

 

[CoyoteThistle]

So, as the LiFePO4 geeks among us know, charging is strictly forbidden if the battery is below 32 degrees F (0 degrees C). Doing so can lead to total loss of the battery. I've been playing with fire, a few times on ski trips and on our last four corners trip, I probably came close to charging when it was too cold. Time to add a layer of protection.

Still very early in the testing, but battery heater attempt v1.0 may be working. Here's what I'm trying:


It's an adhesive-backed 12v heating element that is made to keep external RV drainage pipes from freezing. Found it on Amazon (e-trailer has them too). They claim 7.5 watts and 0.55 amps at 13.5VDC. Made to run continuously and not melt PVC (they stick these right to the pipes by the dump valves). My original plan was to stick these directly on to my battery. My mind went wild though on ways the heater could malfunction and melt through the battery case and lead to a total melt down of some sort. Very low-probability I'm guessing, but I decided to try a different approach first.

My battery is split in to two locations. I started with the upper half


That's looking at the inside of the 1/8" thick plywood box that encloses the upper half of my battery. I spray-adhesived in some insulation (old beat up closed-cell sleeping pad) and a second layer of the light plywood where the heater is stuck on. It's a pretty tight space in there so maybe the modest output of the heater would make a difference even without direct contact to the battery?

Next, needed thermostatic control. Found a little unit on Amazon with a built in 20amp relay - got two, one for each half of the battery. Mounted them up out of the way with an on/off switch.


They have a wired temp sensor that displays in red (in Celsius) and a programmable temperature (in green). Upper half of the battery is in the box at right in the above photo. Temp sensor can be seen in second photo above (at right).

Hooked it up and started experimenting at the relatively warm (but cold for SoCal!) temps. First, amp draw looks spot on at about half an amp. The pad gets warm but not too hot to touch. I let it run for a bit and the temp in the box slowly but steadily rose. I won't claim a rate yet, but very early estimate is maybe 1.5 degrees C per hour. Once it gets up to the set temperature, the relay opens and it turns off the pad. When the temp drops by about 0.3C, the relay closes and the heater comes back on. It seems to get back to the set temp in under 15 minutes and then cycles off. Fairly promising so far. Ultimately, I'd set the thermostats to 3 or 4C and then expect them to cycle on and off to keep it all above freezing.

The lower half of the battery doesn't have a snug little box that I can insulate, so not sure what the plan there is yet. I'll do a bit more testing on what I've done so far before committing to a strategy.

 

[java]

That is exactly what scared me off the LiFePO4 for this go around...... I went AGM again.

Ill follow along to see how it keeps them up. Try to keep track of how much they burn energy wise also!

 

[RAM5500 CAMPERTHING]

That is exactly what scared me off the LiFePO4 for this go around...... I went AGM again.

Ill follow along to see how it keeps them up. Try to keep track of how much they burn energy wise also!

Yeah, im with ya @java! The amount of extra work/parts needed, the idiocincries and complexities of the lipos has me staying with AGM as well.

 

[RAM5500 CAMPERTHING]

The next morning we started touring the ruins. We had this whole site to ourselves for an hour or more - the perfect way to experience such an amazing place.

Nice! This is still to date, one of the coolest places i've ever visited and absolutely awe struck when seeing it in person and the scale of it

 

[Ducstrom]

Awesome! I will be following. I am on the fence still about the lifepo4 batteries or AGM. Going to buy all the components at once when I finally decide which way to go (likely this summer).
I am limited to space for 2 batteries so the extra amps of the Lithium means I can run induction. If I go AGM it'll mean I've got to cut a vent in my insulated battery box and I'll likely have to use a countertop propane stove with the green bottles.
The cold weather charging is one of the major concerns with lithium especially since I am in northern Canada and deal with freezing temps for half the year.
If this works well I could see it being beneficial for AGM too since the usable capacity drops on those as well from what I understand. I wonder if the extra usable capacity of a warmer battery would negate the power used by the heating pad?

 

[Terra Ops]

I have been very happy with our drop in lithiums. Tons of available power and quick recharge. No generator needed. We do however have the batteries located inside
the camper which is well insulated. For those that need a heated insulated box, I wonder if it would make sense to power the heater with a separate battery used in motorcycles, lawnmowers, etc. A simple thermostat could regulate the temp. You would need to figure out the best/efficient way to charge.
Here is what Battle Born has to say;

Are there any temperature restrictions on your LiFePO4 batteries?
Yes, our batteries do have temperature restrictions. The batteries will no longer accept a charge once the temperature drops to 24 degrees F, but they will continue to discharge until the temperature reaches -4 degrees F. We do suggest insulated battery boxes, or heating blankets to help keep the temperature up on the batteries. As far as heat is concerned, the batteries will shut down once the temperature hits 135 degrees F.

Here is a link to their FAQ's. https://battlebornbatteries.com/faq/

Not trying to promote this brand as I have the Stark which are out of business. However, the chemistry and bms seem identical. I have had a few instances where the bms has protected the battery. Not to mention its a simple drop in.

 

[java]

I have been very happy with our drop in lithiums. Tons of available power and quick recharge. No generator needed. We do however have the batteries located inside
the camper which is well insulated. For those that need a heated insulated box, I wonder if it would make sense to power the heater with a separate battery used in motorcycles, lawnmowers, etc. A simple thermostat could regulate the temp. You would need to figure out the best/efficient way to charge.
Here is what Battle Born has to say;

Are there any temperature restrictions on your LiFePO4 batteries?
Yes, our batteries do have temperature restrictions. The batteries will no longer accept a charge once the temperature drops to 24 degrees F, but they will continue to discharge until the temperature reaches -4 degrees F. We do suggest insulated battery boxes, or heating blankets to help keep the temperature up on the batteries. As far as heat is concerned, the batteries will shut down once the temperature hits 135 degrees F.

Here is a link to their FAQ's. https://battlebornbatteries.com/faq/

Not trying to promote this brand as I have the Stark which are out of business. However, the chemistry and bms seem identical. I have had a few instances where the bms has protected the battery. Not to mention its a simple drop in.

What I wonder is why Battle Born and Stark's BMS allows them to go much colder 5han every other BMS. 99% of them cut off at 5C/40F

Sent from my SM-G973U using Tapatalk

 

[CoyoteThistle]

That is exactly what scared me off the LiFePO4 for this go around...... I went AGM again.

Ill follow along to see how it keeps them up. Try to keep track of how much they burn energy wise also!

Yeah, im with ya @java! The amount of extra work/parts needed, the idiocincries and complexities of the lipos has me staying with AGM as well.

I think if space and weight aren't pretty major concerns, AGM still makes sense for most builds. Efficient charging and long lifetime of Lithium may be good reasons for some as well (e.g., full-timers living off solar).

Yeah, interested in the energy usage of the heaters too, I'll try to track it but I have to travel a bit to get to below-freezing temps and it refuses to snow in the Sierras this year ? Guess I need to pack up and head to Jackson Hole or something!

 

[CoyoteThistle]

Nice! This is still to date, one of the coolest places i've ever visited and absolutely awe struck when seeing it in person and the scale of it

Yeah, I'm with you. Truly a special place. Inspired by that trip, I just read Craig Childs "House of Rain", which tracks the history of Chaco civilization and the Anasazi more broadly. Good read.

 

[CoyoteThistle]

Awesome! I will be following. I am on the fence still about the lifepo4 batteries or AGM. Going to buy all the components at once when I finally decide which way to go (likely this summer).
I am limited to space for 2 batteries so the extra amps of the Lithium means I can run induction. If I go AGM it'll mean I've got to cut a vent in my insulated battery box and I'll likely have to use a countertop propane stove with the green bottles.
The cold weather charging is one of the major concerns with lithium especially since I am in northern Canada and deal with freezing temps for half the year.
If this works well I could see it being beneficial for AGM too since the usable capacity drops on those as well from what I understand. I wonder if the extra usable capacity of a warmer battery would negate the power used by the heating pad?

That seems like a tough call. Dealing with green bottles sucks, but worrying all winter about your $$ battery being ruined might be rough. Maybe it depends on your usage. If you aren't using the camper in the cold months, you could design it so you just pull the batteries, put them in a closet in your house, and wait for spring. In shoulder seasons with cold nights, a simple battery heater like this might make it feasible. Designing a good insulated battery box (which I didn't do) seems helpful too.

Enjoying your build thread btw, looking great!