wired for solar...sorta! (MC4s on the roof) - R-pod Owners Forum

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podwerkz

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Joined: 11 Mar 2019
Location: Texas
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Posts: 966

Topic: wired for solar...sorta! (MC4s on the roof)
Posted: 18 Mar 2019 at 4:24pm

Success!

I found the beefy 10 ga wires, 4 of them, (no markings at all) behind the Furrion Radio, which I had to remove, and found a rats nest of wires back in that compartment. One pair has battery voltage, (with no protection of the cut ends!) and two of them were...zilch. I clipped a 10 ohm resistor across those two, went up on the roof, and voila, 10 ohms reading on the meter!

Then I set one of my panels, a 50 watt Grape Solar, up on the roof, and attached it to the MC4s.

Presto! 22 volts on those wires in the pod radio cabinet!

I made progress...it was just not being able to find those wires that had me bum-fuzzled.

Thanks guys!

r･pod 171 gone but not forgotten!

offgrid

Senior Member

Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 18 Mar 2019 at 4:54pm

Congrats! I do believe you've got it. So that's where your charge controller is supposed to go. If you can run a new pair of wires to there from an external location where you can plug in your portable solar module then you're home free. Otherwise, you could splice the 4 wires together in the cabinet, disconnect the other ends from the battery, and locate your controller near the battery.

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

podwerkz

Senior Member

Joined: 11 Mar 2019
Location: Texas
Online Status: Offline
Posts: 966

Posted: 18 Mar 2019 at 5:19pm

Yep...looking over some options. It would be nice to have the new flush mount controller there, but then I have to run a lot of wires one way or another to incorporate the portable panels on the ground, and the battery temp and battery voltage sensors for the controller.

By the way I have had good luck with a Renogy Adventurer in my camper truck, with AGMs, but the new version of that controller has LI settings...which basically eliminate 'equalization' and 'float' modes.

It also provides adjustable boost voltage, in .2v steps. Should work out well for the Battle Born LiFePo4.

That is the one I have ordered.

BTW while I was in there, I discovered why the Furrion radio has no AM receive. They run the antenna for the radio thru the TV antenna pre-amp with a splitter, and of course, AM signals dont like that tiny rubber whip antenna on the roof, nor the higher range 88mhz to probably 400 mhz amplifier for the FM radio and the TV signals. Hooked up a shorth length of wire to the Furrion antenna jack and it pulled in local AM stations with no problem.

I'm a fan of AM radio when I can listen to talk shows etc, so I will be adding a seperate antenna for AM, and probably eliminating the connection to the TV pre-amp. I might end up getting an A-B switch just in case I need a boosted FM signal...unlikely since the Furrion radio can sync with my smartphone for all the music I want!

Yeah I know, AM radio!

I'm old school...

r･pod 171 gone but not forgotten!

offgrid

Senior Member

Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 18 Mar 2019 at 6:27pm

I really don't listen to any OTA broadcasts. 100% internet streaming for me. I'm getting rid of my roof antenna to make room for more solar Wink

I'm sure the Relogy controller is fine, but I didn't think the Li batteries need any boost charging at all. Just don't allow overvoltage and don't charge if its too cold. And, do you really need temp comp wires for Li batteries? Most controllers I've seen have that turned off for Li.

With 10AWG wires and what, around 10-11 peak amps solar, your voltage drop should only be 2-3 tenths of a volt, right? Not sure you really need voltage sense wires either. Li batteries are really pretty easy to maintain compared to PbA, the biggest issue is cell balancing which Battleborn takes care of.

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

podwerkz

Senior Member

Joined: 11 Mar 2019
Location: Texas
Online Status: Offline
Posts: 966

Posted: 18 Mar 2019 at 6:56pm

LiFePo4 batteries do need a 'boost' when on solar to fully charge them as fast as possible, or less boost if you want a slower more complete charge, as in a 24/7 shore-power hookup.

But also, I don't foresee ever fully depleting this thing...my typical use of batteries and DC power is fairly conservative. No trolling motors or microwaves running on inverters. Mainly, just charging the phone and laptop, a wifi hotspot, running a radio or two, some LED lights, etc.

I emailed Battle Born recently, and asked exactly what are the parameters in cold weather.

You can see some stats online, but I wanted the exact cut-off points for low temperature operation.

According to the email I received from Battle Born, the Battle Born batteries cease to accept any input charge current below 24 degrees, and will not accept charge current until the internal sensor in the battery recovers to above 32 degrees. You can DRAW power below those temps, but you cant shove any in.

I don't know for sure if the Renogy controller will shut off charge current at cold temps, but I would assume that it will, when LI is selected as the battery. If the temp probe is absent or not placed in the battery compartment, the controller will not 'know' the battery temps.

We've had some cold weather here, but hopefully it will stay warm for awhile now, so the dayime freezing temps below 25 degrees or so should be over with for the season.

r･pod 171 gone but not forgotten!

offgrid

Senior Member

Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 19 Mar 2019 at 6:03am

The limitation against charging the Battle Born batteries below freezing is consistent with all Li batteries I think. But if the battery is self protected against charging when its too cold then it doesn't matter what the the controller thinks the temperature is.

I'd be more concerned with bricking a Li battery under freezing conditions, if its cold and discharged and you can't charge it, you'll have a real problem. When I convert to Li I'm planning to put my batteries inside the trailer in the heated space. They don't out gas like PbA batteries do so that should be fine.

I looked at the "boost" settings for the Renogy Adventurer and it looks like for Li batteries then boost time is indefinite, so its not really a "boost" setting, just a fixed max charge voltage setting. Also, on solar the battery charge rate will be controlled by how much solar irradiance you're getting, not by the battery charge voltage setting. IOW, you can set the charge voltage on the controller where you want it and leave it alone.

The Battle Born literature calls for a single max charge setting in the range of 14.2-14.6V, no boost, float, or equalizaion required. LiFePo4 cells have a max recommended voltage of 3.6 V per cell, or 14.4V, which is also Battle Born's recommendation. I'd personally stay a little below that, say at around 3.55 Vpc or 14.2, because overcharging Li batteries can result in thermal runaway, and also because Li battery lifetime is increased if you keep the charge voltage lower than max. The only downside is a very slightly lower available capacity, not a big deal.

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

podwerkz

Senior Member

Joined: 11 Mar 2019
Location: Texas
Online Status: Offline
Posts: 966

Posted: 19 Mar 2019 at 10:57am

'Boost' on the Renogy controller is also called 'absorption' on other controllers, but it's the main charging phase, the one you want when you have sunlight. So yeah, same thing. And it is adjustable up to 16v so they refer to it as 'boost'...to those of us with lead acid experience we would typically refer to that as absorption (or equalization). Sorry for the confusion, I was using their terminology. With lead acid, we are used to 3 and 4 stage chargers, but for lithium...its ONE stage, sometimes two. Whatever they call it, it's the one where energy is being returned to the battery.

And I'm looking at moving the lithium battery box inside the camper.... that falls under the other options I mentioned. That would solve the temperature and temp sensor issue, and make a bit of space on the tongue frame to put a storage box for chains, jacks, etc. The 171 has limited outside storage space.

The BattleBorn is a lot lighter, so I'm not worried about the weight of it on the inside floor of the trailer, bouncing down the road, and I can mount it on a piece of plywood to spread the load, of course the battery will be in a battery box as it is on the tongue, and inside the forward cabinet under the dinette, near the converter/charger.

Supposedly the LiFePo4 chemistry is less prone to thermal runaway, and during the extreme heat of the summer, or the deep cold during winter, I would think the lithium chemistry would be 'happier' in a stable indoor temperature.

I know that my lithium-ion drone flight batteries and my lithium e-bike batteries are 'picky' about low temps. The drone simply will not launch if the battery temps are too low. The e-bike has reduced range when it's really cold. Which is fine, since I dont ride it long distances in the frigid temps anyway!

Renogy sent an email advising my controller is on the way, so we are getting close to 'crunch time'!

r･pod 171 gone but not forgotten!

offgrid

Senior Member

Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 19 Mar 2019 at 11:33am

Sounds like a good plan if you can route conductors from the gopower controller location you found to your new battery location. Using a battery box under there is optional I think, as long as the positive battery terminal is protected from something falling on it.

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

podwerkz

Senior Member

Joined: 11 Mar 2019
Location: Texas
Online Status: Offline
Posts: 966

Posted: 19 Mar 2019 at 1:06pm

Currently (see what I did there?) I'm running a few items on battery power in the trailer, no shore power.

A couple of LED lights, the radio, and the vent fan, with occasional operation of other lights and USB ports. They have all been running continuously for about a day and still seeing 13.2v on the Battle Born. Of course the 'battery monitor' lights still show Full.

Back in early February, out in SW Arizona, I used this Battle Born in my other trailer, with some heavier loading, and only saw it drop to 13.1 a couple of times, and it would return to 13.2 when the loads were removed.

Running a small generator the next morning for a half hour to an hour or so, into a 15 amp charger, the battery recovered quickly up to above 14 volts. Then the solar panels kept it topped it off the rest of the day.

That's one of the advantages to the LiFePo4: Quick recharge times. So far, I like it.

r･pod 171 gone but not forgotten!

offgrid

Senior Member

Joined: 23 Jul 2018
Online Status: Offline
Posts: 5290

Posted: 19 Mar 2019 at 3:41pm

Li batteries are "currently" the best batteries you can get by far. I'm working up to getting a salvage 5.2kwh 22V Tesla Li Ion pack for my 179. 50 lbs for 5.2kWh isn't bad. Considering that 80% of that is useful capacity vs 50% for PbA the weight of an equivalent PbA pack would be about 200 lbs, way too much for an rPod.

Please do be sure that your charger is also limited to 14.4V max.

1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold

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podwerkz Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966	Topic: wired for solar...sorta! (MC4s on the roof) Posted: 18 Mar 2019 at 4:24pm
	Success! I found the beefy 10 ga wires, 4 of them, (no markings at all) behind the Furrion Radio, which I had to remove, and found a rats nest of wires back in that compartment. One pair has battery voltage, (with no protection of the cut ends!) and two of them were...zilch. I clipped a 10 ohm resistor across those two, went up on the roof, and voila, 10 ohms reading on the meter! Then I set one of my panels, a 50 watt Grape Solar, up on the roof, and attached it to the MC4s. Presto! 22 volts on those wires in the pod radio cabinet! I made progress...it was just not being able to find those wires that had me bum-fuzzled. Thanks guys!
	r･pod 171 gone but not forgotten!

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 18 Mar 2019 at 4:54pm
	Congrats! I do believe you've got it. So that's where your charge controller is supposed to go. If you can run a new pair of wires to there from an external location where you can plug in your portable solar module then you're home free. Otherwise, you could splice the 4 wires together in the cabinet, disconnect the other ends from the battery, and locate your controller near the battery.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

podwerkz Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966	Posted: 18 Mar 2019 at 5:19pm
	Yep...looking over some options. It would be nice to have the new flush mount controller there, but then I have to run a lot of wires one way or another to incorporate the portable panels on the ground, and the battery temp and battery voltage sensors for the controller. By the way I have had good luck with a Renogy Adventurer in my camper truck, with AGMs, but the new version of that controller has LI settings...which basically eliminate 'equalization' and 'float' modes. It also provides adjustable boost voltage, in .2v steps. Should work out well for the Battle Born LiFePo4. That is the one I have ordered. BTW while I was in there, I discovered why the Furrion radio has no AM receive. They run the antenna for the radio thru the TV antenna pre-amp with a splitter, and of course, AM signals dont like that tiny rubber whip antenna on the roof, nor the higher range 88mhz to probably 400 mhz amplifier for the FM radio and the TV signals. Hooked up a shorth length of wire to the Furrion antenna jack and it pulled in local AM stations with no problem. I'm a fan of AM radio when I can listen to talk shows etc, so I will be adding a seperate antenna for AM, and probably eliminating the connection to the TV pre-amp. I might end up getting an A-B switch just in case I need a boosted FM signal...unlikely since the Furrion radio can sync with my smartphone for all the music I want! Yeah I know, AM radio! I'm old school...
	r･pod 171 gone but not forgotten!

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 18 Mar 2019 at 6:27pm
	I really don't listen to any OTA broadcasts. 100% internet streaming for me. I'm getting rid of my roof antenna to make room for more solar. I'm sure the Relogy controller is fine, but I didn't think the Li batteries need any boost charging at all. Just don't allow overvoltage and don't charge if its too cold. And, do you really need temp comp wires for Li batteries? Most controllers I've seen have that turned off for Li. With 10AWG wires and what, around 10-11 peak amps solar, your voltage drop should only be 2-3 tenths of a volt, right? Not sure you really need voltage sense wires either. Li batteries are really pretty easy to maintain compared to PbA, the biggest issue is cell balancing which Battleborn takes care of.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

podwerkz Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966	Posted: 18 Mar 2019 at 6:56pm
	LiFePo4 batteries do need a 'boost' when on solar to fully charge them as fast as possible, or less boost if you want a slower more complete charge, as in a 24/7 shore-power hookup. But also, I don't foresee ever fully depleting this thing...my typical use of batteries and DC power is fairly conservative. No trolling motors or microwaves running on inverters. Mainly, just charging the phone and laptop, a wifi hotspot, running a radio or two, some LED lights, etc. I emailed Battle Born recently, and asked exactly what are the parameters in cold weather. You can see some stats online, but I wanted the exact cut-off points for low temperature operation. According to the email I received from Battle Born, the Battle Born batteries cease to accept any input charge current below 24 degrees, and will not accept charge current until the internal sensor in the battery recovers to above 32 degrees. You can DRAW power below those temps, but you cant shove any in. I don't know for sure if the Renogy controller will shut off charge current at cold temps, but I would assume that it will, when LI is selected as the battery. If the temp probe is absent or not placed in the battery compartment, the controller will not 'know' the battery temps. We've had some cold weather here, but hopefully it will stay warm for awhile now, so the dayime freezing temps below 25 degrees or so should be over with for the season.
	r･pod 171 gone but not forgotten!

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 19 Mar 2019 at 6:03am
	The limitation against charging the Battle Born batteries below freezing is consistent with all Li batteries I think. But if the battery is self protected against charging when its too cold then it doesn't matter what the the controller thinks the temperature is. I'd be more concerned with bricking a Li battery under freezing conditions, if its cold and discharged and you can't charge it, you'll have a real problem. When I convert to Li I'm planning to put my batteries inside the trailer in the heated space. They don't out gas like PbA batteries do so that should be fine. I looked at the "boost" settings for the Renogy Adventurer and it looks like for Li batteries then boost time is indefinite, so its not really a "boost" setting, just a fixed max charge voltage setting. Also, on solar the battery charge rate will be controlled by how much solar irradiance you're getting, not by the battery charge voltage setting. IOW, you can set the charge voltage on the controller where you want it and leave it alone. The Battle Born literature calls for a single max charge setting in the range of 14.2-14.6V, no boost, float, or equalizaion required. LiFePo4 cells have a max recommended voltage of 3.6 V per cell, or 14.4V, which is also Battle Born's recommendation. I'd personally stay a little below that, say at around 3.55 Vpc or 14.2, because overcharging Li batteries can result in thermal runaway, and also because Li battery lifetime is increased if you keep the charge voltage lower than max. The only downside is a very slightly lower available capacity, not a big deal.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

podwerkz Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966	Posted: 19 Mar 2019 at 10:57am
	'Boost' on the Renogy controller is also called 'absorption' on other controllers, but it's the main charging phase, the one you want when you have sunlight. So yeah, same thing. And it is adjustable up to 16v so they refer to it as 'boost'...to those of us with lead acid experience we would typically refer to that as absorption (or equalization). Sorry for the confusion, I was using their terminology. With lead acid, we are used to 3 and 4 stage chargers, but for lithium...its ONE stage, sometimes two. Whatever they call it, it's the one where energy is being returned to the battery. And I'm looking at moving the lithium battery box inside the camper.... that falls under the other options I mentioned. That would solve the temperature and temp sensor issue, and make a bit of space on the tongue frame to put a storage box for chains, jacks, etc. The 171 has limited outside storage space. The BattleBorn is a lot lighter, so I'm not worried about the weight of it on the inside floor of the trailer, bouncing down the road, and I can mount it on a piece of plywood to spread the load, of course the battery will be in a battery box as it is on the tongue, and inside the forward cabinet under the dinette, near the converter/charger. Supposedly the LiFePo4 chemistry is less prone to thermal runaway, and during the extreme heat of the summer, or the deep cold during winter, I would think the lithium chemistry would be 'happier' in a stable indoor temperature. I know that my lithium-ion drone flight batteries and my lithium e-bike batteries are 'picky' about low temps. The drone simply will not launch if the battery temps are too low. The e-bike has reduced range when it's really cold. Which is fine, since I dont ride it long distances in the frigid temps anyway! Renogy sent an email advising my controller is on the way, so we are getting close to 'crunch time'!
	r･pod 171 gone but not forgotten!

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 19 Mar 2019 at 11:33am
	Sounds like a good plan if you can route conductors from the gopower controller location you found to your new battery location. Using a battery box under there is optional I think, as long as the positive battery terminal is protected from something falling on it.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold

podwerkz Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 11 Mar 2019 Location: Texas Online Status: Offline Posts: 966	Posted: 19 Mar 2019 at 1:06pm
	Currently (see what I did there?) I'm running a few items on battery power in the trailer, no shore power. A couple of LED lights, the radio, and the vent fan, with occasional operation of other lights and USB ports. They have all been running continuously for about a day and still seeing 13.2v on the Battle Born. Of course the 'battery monitor' lights still show Full. Back in early February, out in SW Arizona, I used this Battle Born in my other trailer, with some heavier loading, and only saw it drop to 13.1 a couple of times, and it would return to 13.2 when the loads were removed. Running a small generator the next morning for a half hour to an hour or so, into a 15 amp charger, the battery recovered quickly up to above 14 volts. Then the solar panels kept it topped it off the rest of the day. That's one of the advantages to the LiFePo4: Quick recharge times. So far, I like it.
	r･pod 171 gone but not forgotten!

offgrid Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290	Posted: 19 Mar 2019 at 3:41pm
	Li batteries are "currently" the best batteries you can get by far. I'm working up to getting a salvage 5.2kwh 22V Tesla Li Ion pack for my 179. 50 lbs for 5.2kWh isn't bad. Considering that 80% of that is useful capacity vs 50% for PbA the weight of an equivalent PbA pack would be about 200 lbs, way too much for an rPod. Please do be sure that your charger is also limited to 14.4V max.
	1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold