Li-thiiii-um.... continued.

[John in Santa Cruz]

so cogitating my lithium upgrade, I'm looking at the SOK 12V 206AH... and went to look at the dimensions, and its the nearly exactly same size as a GC2 ?!? 11.42" * 7.87" * 11.02" to be specific. can that be legit ?

https://www.amazon.com/SOK-Battery-R...dp/B087BJYGV4/
vs some other non-name alternatives (which tend to different dimensions)...
https://www.amazon.com/Lithium-LiFeP.../dp/B088RM4W48
https://www.amazon.com/Zooms-Lithium.../dp/B09DY2QKRQ
https://www.amazon.com/ExpertPower-L.../dp/B08CJYSG3H

these latter all seem to be in the 20 x 9 x 8 inch range.

[BobG]

John, You probably already know this but I will mention it anyway. Will Prowse has tested and torn down quite a few batteries. I believe he has a list of batteries that he feels are quality construction that meet their advertised specifications. I don't know where on his site they are listed but have heard him say to check his list. I am pretty sure the SOK battery is on his list. I originally ordered SOK but cancelled order when I realized the continuous amp draw was not enough for what I wanted to do. I am concerned that I may eventually regret my decision.
He has YouTube videos on each of his battery tests. Hopefully you can find his list on this site.

https://www.mobile-solarpower.com/

[John in Santa Cruz]

Originally Posted by BobG

John, You probably already know this but I will mention it anyway. Will Prowse has tested and torn down quite a few batteries. I believe he has a list of batteries that he feels are quality construction that meet their advertised specifications. I don't know where on his site they are listed but have heard him say to check his list. I am pretty sure the SOK battery is on his list. I originally ordered SOK but cancelled order when I realized the continuous amp draw was not enough for what I wanted to do. I am concerned that I may eventually regret my decision.
He has YouTube videos on each of his battery tests. Hopefully you can find his list on this site.

https://www.mobile-solarpower.com/

ok, its like the top battery on his list, heh. says they are built like a tank, and built to be repaired.

100 amp per battery max discharge, I plan on running two of the 200AH in parallel, but I don't expect to every need anywhere close to 100A, more like max 50A for short periods, and mostly well under 25 amps. mostly its so I can run a compressor fridge for like a week of dry camping and not sweat it. initial solar plan is a 360 W rooftop panel, which I figure will at most be outputting 300 watts or 20-25 amps, so likely will take 4 days of summer sunshine to fully charge a deeply discharged 400AH LFP setup (assuming 4 hours/day of 300W output equivalent).

gonna be upgrading to the PD4655L so I'll have 55 amps of charging when I do have house power, thats about 700 watts.

[BobG]

I was very impressed with SOK when I had to cancel my order. That was over a year ago. He was very concerned why I was cancelling and wanted to make things right. When he understood, he immediately returned my money.



I wanted 24 volt system and ability to run air conditioning for short periods of time. I did install 1080 watts of solar. I might have been able to make SOK batteries work but at the time I didn't have much knowledge.


I do have the DC558 refrigerator and have run it 6 days during warm summer without any charging of the batteries. It wasn't a good test because I only opened the door for occasional beer. Batteries are 2 x 170Ah 12V that I run in series for 24 volts.



My wiring between the converter and batteries was poor and had a large voltage drop when the GoPower was charging at bulk rate of 55 amps. I replaced all the wiring and actually replaced the converter with an inverter/charger.


I have the gopower converter with the lithium charging switch. I re-wired it for charging only and was going to keep it for charging 12 volt batteries but have decided to not carry it around in the trailer. Would you be interested in it?

[John in Santa Cruz]

so I just ordered 2 206AH SOK's, heh. as I said, planning to parallel them, so thinking I should use my NOCO Genius 10 in its LI mode to top both off separately before connecting... LI mode is 14.6V at 10A max until fully charged.

ordered 10 feet each black + red 4 AWG in to wire this up, and a couple 100A ANL fuse pods to put directly on the battery +. I've already got a smart shunt

I think I'll cut a piece of ply to mount under my curbside bench to install stuff on...

so, solar panel -> Victron MPPT 100/30 to the + and - battery terminals on the 'board'

batteries in existing batt box, both negs to the SmartShunt, then to the negative terminal on the board, velcro tape the 100A fuses to the top of each battery near the + terminal, then run those two + wires to the + terminal on the board.

+ and - terminals on the board wired to the WFCO power center.

oh, and those two batts /should/ fit in my existing battery box. I think this gives me something like nearly 5000 watt*hours usable power.

should I have separate fuses on the output of the solar MPPT? what about on the solar side? I kinda thought the solar stuff was short resistant, and it would just drop the voltage if the current limits were exceeded, and its only 10 amps max anyways.

[John in Santa Cruz]

one thing I'm worried about, the 14.6V output of the PD4655L could be too much for my Maxifan Deluxe, but I have a couple little 6 or 8 amp 12V to 12V DC-DC regulators, so I figure I'll install one of those on the fuse output that drives the street side LED lighting and the maxifan. now, I know the maxifan on its highest setting can exceed 8 amps, but I don't think we've EVER used that except just to laugh at how noisy it is, so we'll just have to be careful.

I'm pretty sure my older (2002) truck's alternator pretty much always outputs 14V or so when its got a load, so I'm not real worried about needing a DC-DC to keep the li from feeding the truck. I've always been careful to unplug AC power *before* plugging in the vehicle, and unplugging the vehicle *before* plugging in the AC power. and vehicle OFF disconnects the trailer power on mine.

[Perry Butler]

Originally Posted by John in Santa Cruz

one thing I'm worried about, the 14.6V output of the PD4655L could be too much for my Maxifan Deluxe, but I have a couple little 6 or 8 amp 12V to 12V DC-DC regulators, so I figure I'll install one of those on the fuse output that drives the street side LED lighting and the maxifan.

This is a known MaxxFan problem. A month after installing our SiO2 batteries our MaxxFan light came on and the fan quit working. After resetting the power it would run for a day or two and then get wonky again. The running time got shorter and shorter until it was lucky to run 5 minutes. The SiO2's were charging at 14.6. Coincidence?

I called MaxxAir and they said many boards have failed, almost all because the owner installed LiFePo4 batteries and charge > 14.4. The board they sent is supposed to handle the higher charge rates. I put the new board in last November (2021) so we'll see how long it lasts.

I now charge at 14.4 and have no problems keeping the batteries full, but it sounds like even 14.4 can reek havoc with the MaxxFan with an older board. When over 45F our MaxxFan runs 24/7 on low. We'll see how long this board lasts.

Enjoy,

Perry

[rubicon327]

Originally Posted by BobG

I wanted 24 volt system and ability to run air conditioning for short periods of time. I did install 1080 watts of solar. I might have been able to make SOK batteries work but at the time I didn't have much knowledge.

I guess you realized that at 24V you cut your amperage in half? Curious about your system. Are you running a standard Dometic or Coleman rooftop A/C unit? That takes some serious hardware to make that work. I can relate. I can run my 9,000 BTU mini-split A/C for 6 hours +/- on a hot day off a 400AH lithium battery and 2000W Xantrex Freedom XC inverter/charger. Adding some solar next but can probably only manage 400-500W on a 19. Does your 1080W include portable ground deployed?

[BobG]

Rubicon327, You are correct that I wanted to cut the amperage in half. I have an Escape 21 and put the 2 batteries and all equipment under the driver side dinette bench. I did remove the supplied converter and installed the Victron MultiPlus. I did install 2 AC and 1 DC electric panels in the area above the bench next to the bathroom. I can add a couple more batteries in the passenger dinette bench later if I need to but if it gets to where I need air conditioning during the day instead of just bed time, I will probably head to cooler places rather than add more batter. I have 170 Ah at 24 volts.



I have the Coleman 13,500 BTU easy start Mach 10?. It switches seamlessly between the shore power and inverter.


I have 210 watt solar panels front and back. I was too nervous to install larger panels but really wanted to use the Panasonic HIT 340 watt panels or similar. Even thought about the 370 watt Panasonic but in the end I was just too nervous. The front and back are in series so needed to be the same size panel.



I have 2 x 160 watt panels on each side. All 4 are connected in series. The AC will shade a panel on one side or the other for most of the day so I don't really have 1080 watts available at any one time except for maybe a brief half hour.



The solar panel mounting is 1 rail attached to 5 x L brackets through bolted on each side of the trailer. I used AM Solar clips and AM Solar mounting brackets taped to the roof for the additional mounts. There are 2 of these on each smaller panel and 4 of these added to each larger panel. The large panels are attached to the rail on each side and the smaller panels are attached to a rail. It is not the best layout or system but it is what I ended up with. The uneven roof made it difficult and I didn't want to just attach the panels at the corners or through bolt brackets where they could be seen. I just pealed back the foam inside the upper cabinets and wardrobe closet to install the 10 L brackets. Can't see where the bolt heads are but can feel them. I added a piece of HDPE with caulking type adhesive and 2 1/2" fender washer under the bolt heads.

[alanmalk]

Originally Posted by BobG

...

I have 2 x 160 watt panels on each side. All 4 are connected in series. The AC will shade a panel on one side or the other for most of the day so I don't really have 1080 watts available at any one time except for maybe a brief half hour.
...

This caught my attention...

Per:
https://www.aurorasolar.com/blog/sha...mitigate-them/

"In his book Renewable Energy and Efficient Electric Power Systems Stanford University’s Gil Masters demonstrates how shading just one out of 36 cells in a small solar module can reduce power output by over 75%."

This could reduce your power far more than using the wrong size wire, methinks.

[BobG]

I believe that shading 1 cell in a module can cut output of the module by 75% or even cut a whole string of modules if they are in series. However, modern modules have bypass diodes so this doesn't happen. A little shading can still cause complete loss of the string of cells that shaded cell is located in but if there are bypass diodes properly wired into the module then current is bypassed around the shade affected string of cells and life goes on.


Here is video explaining this better than I can.

https://www.youtube.com/watch?v=-x_6OLdAods

[Perry Butler]

Originally Posted by BobG

I believe that shading 1 cell in a module can cut output of the module by 75% or even cut a whole string of modules if they are in series. However, modern modules have bypass diodes so this doesn't happen. A little shading can still cause complete loss of the string of cells that shaded cell is located in but if there are bypass diodes properly wired into the module then current is bypassed around the shade affected string of cells and life goes on.

Yes, Gil Master's papers are from 2017 and earlier. Quality panels for RV's today have diodes, so a shaded panel minimally affects the output of the other non-shaded panels. Do your homework!

Enjoy,

Perry

[Perry Butler]

Originally Posted by BobG

I believe that shading 1 cell in a module can cut output of the module by 75% or even cut a whole string of modules if they are in series. However, modern modules have bypass diodes so this doesn't happen. A little shading can still cause complete loss of the string of cells that shaded cell is located in but if there are bypass diodes properly wired into the module then current is bypassed around the shade affected string of cells and life goes on.

Yes, Gil Master's paper was published in 2004. According to Arizona Wind & Sun, solar farms are exchanging their 4-7 year old panels for panels that can absorb 2-4 times the watts in the early and late portions of the day, among other reasons. The changes in solar panels since 2004 have been huge, even many since 2017.

_________________________________________

Quality panels for RV's today have diodes, so a shaded panel minimally affects the output of the other non-shaded panels. If the panel you're looking at doesn't claim diodes, it probably doesn't have diodes and you should walk away. Diodes are a huge selling point for RV's. Do your homework!

Enjoy,

Perry

[rubicon327]

Originally Posted by BobG

Rubicon327, You are correct that I wanted to cut the amperage in half. I have an Escape 21 and put the 2 batteries and all equipment under the driver side dinette bench. I did remove the supplied converter and installed the Victron MultiPlus. I did install 2 AC and 1 DC electric panels in the area above the bench next to the bathroom. I can add a couple more batteries in the passenger dinette bench later if I need to but if it gets to where I need air conditioning during the day instead of just bed time, I will probably head to cooler places rather than add more batter. I have 170 Ah at 24 volts.

I have the Coleman 13,500 BTU easy start Mach 10?. It switches seamlessly between the shore power and inverter.

I have 210 watt solar panels front and back. I was too nervous to install larger panels but really wanted to use the Panasonic HIT 340 watt panels or similar. Even thought about the 370 watt Panasonic but in the end I was just too nervous. The front and back are in series so needed to be the same size panel.

I have 2 x 160 watt panels on each side. All 4 are connected in series. The AC will shade a panel on one side or the other for most of the day so I don't really have 1080 watts available at any one time except for maybe a brief half hour.

The solar panel mounting is 1 rail attached to 5 x L brackets through bolted on each side of the trailer. I used AM Solar clips and AM Solar mounting brackets taped to the roof for the additional mounts. There are 2 of these on each smaller panel and 4 of these added to each larger panel. The large panels are attached to the rail on each side and the smaller panels are attached to a rail. It is not the best layout or system but it is what I ended up with. The uneven roof made it difficult and I didn't want to just attach the panels at the corners or through bolt brackets where they could be seen. I just pealed back the foam inside the upper cabinets and wardrobe closet to install the 10 L brackets. Can't see where the bolt heads are but can feel them. I added a piece of HDPE with caulking type adhesive and 2 1/2" fender washer under the bolt heads.

Since solar is my next big project do you have any pictures to share or did you document this on another thread?

[BobG]

Rubicon, Here are some pictures of the electrical. It is really difficult for me to crawl under the table and deal with fuses and breakers so I moved things to where I could access them.

I will take pictures of the solar panel mounting when the snow melts in a few days.

[dstreight]

Just a quick FYI/FWIW based upon the last 2+ years of running our all electric 15A with 6500watt-hour LFP (Fortune Prismatic cells...) and 400/800w of solar atop our little roof + 170w Merlin portable.

Lessons learned: During the higher angle sun months the above system using 800w of solar works great; we're never at a want for more amps. But during the lower angle sun months, namely mid-October and November and similarly in the early spring, 800w of solar (flat) isn't enough to keep the battery sufficiently re-charged.

Adding the portable 170w Merlin panel to the 800w rooftop array (using its own Victron controller along with the larger Victron controller for the 800w) with a Smart network really helps bridge the gap.

If I had a bit more real estate atop the 15A I'd like to get 1000-1200w of permanently mounted panels but that just isn't going to happen with today's panel tech.

Lesson: If you're planning for all or nearly all electric sans a generator, you're more than likely going to need considerably more solar generating capability and quite possibly a bigger battery mainly for late fall and early spring camping.

[Ron in BC]

Originally Posted by BobG

Rubicon, Here are some pictures of the electrical. It is really difficult for me to crawl under the table and deal with fuses and breakers so I moved things to where I could access them.

Well that's brilliant. It's the one mod that I'd love to do but haven't. All my life I've had boats with wall mounted, easily accessible panels. I hate getting down on my knees and crawling under the table to flip a breaker etc.

This panel was in a boat that I chartered in Nov. All the time I had it I was looking at it and thinking, "I really have to put a wall mounted panel in." The boat panel was OK but the volt meter was laughable.

It looks like the wiring runs to your new location weren't too long. Unfortunately while that would be a great location for a panel in a 21C the wiring runs would a little on the long side unless I relocated the batteries.

Good work, always nice to see a new mod.

Ron

[John in Santa Cruz]

so crawled under my dinette table to swap out the WFCO 8955's power converter for the PD4655 that arrived the other day. BTW, yes, absolutely confirmed, generic PD4655 *DO* have the lithium jumper now.

again, like the last WFCO I swapped for a guy with dead power in 105F weather in Chico last summer in his large older stick-built, the fridge and converter AC wires are tied together with a shrinkwrapped crimped 'Y' connector to stick under the top circuit breaker.

UGH to that. I think I'm going to get a compatible breaker and install it in the next slot down, so I can put the fridge on its own, and leave the top breaker just for the converter. is that too crazy ?

breaker panel (with "Y" wire removed from 2nd breaker from top)


said "Y" wire...



so I guess its a trip to the local electrical supply to get an Eaton BD1515 breaker and move the fridge down to it....

[rubicon327]

Originally Posted by John in Santa Cruz

so crawled under my dinette table to swap out the WFCO 8955's power converter for the PD4655 that arrived the other day. BTW, yes, absolutely confirmed, generic PD4655 *DO* have the lithium jumper now.

again, like the last WFCO I swapped for a guy with dead power in 105F weather in Chico last summer in his large older stick-built, the fridge and converter AC wires are tied together with a shrinkwrapped crimped 'Y' connector to stick under the top circuit breaker.

UGH to that. I think I'm going to get a compatible breaker and install it in the next slot down, so I can put the fridge on its own, and leave the top breaker just for the converter. is that too crazy ?

breaker panel (with "Y" wire removed from 2nd breaker from top)


said "Y" wire...



so I guess its a trip to the local electrical supply to get an Eaton BD1515 breaker and move the fridge down to it....

The utility pigtail is common for wiring RV converters. I ditched it and put on dedicated 15A breaker like you are contemplating. Worked out well especially since it is now only a backup and a Xantrex Freedom XC inverter/charger takes care of the lithium battery.

[John in Santa Cruz]

I may have to rewire all the way back to the converter to get max charge rates. I have some AWG4 wire. But for now, I was hoping to leave the basic wires along, and connect them. I am replacing 2 x GC2 6V 210AH flooded golf cart batteries with 2 x 12V 200AH LiFePO4 in parallel.