Portable Power Grid - Whole House System

[Jhp230gr45]

I built mine to be movable since we live off grid only for part of the year. The 24 v system now has 8 six volt batteries unlike the picture. When I flip the switch on in the cabin it runs lights, plugs, water well and fans... Everything else runs on propane except washer / dryer that I run the generator for through the power system.. It will also run small appliances, tv, etc. for short periods.

At the end of the season I unplug the power cord from the wall where it goes into breaker box inside and the remote switch cable, roll them up, hook on the tractor and roll it into a storage cubicle and lock it up... The batteries are disconnected and trickle charged over the winter on a harbor freight solar system with dual charge controllers and are ready to go when we come back in the spring...

It works well for the most part with the exception that I'm struggling with power loss overnight from batteries even when system is not in use... Not sure if is because of my 60 amp controller on the trailer or power is slipping out through solar panels... Still trying to figure out that issue...

 

[sunshine_eggo]

It works well for the most part with the exception that I'm struggling with power loss overnight from batteries even when system is not in use... Not sure if is because of my 60 amp controller on the trailer or power is slipping out through solar panels... Still trying to figure out that issue...

Please elaborate on the components and how you observe the power loss.

 

[Jhp230gr45]

The system is entirely AIMS... Not sure if I'm overall impressed as i know technology is getting better by the year... The system is 6 years old...

The panels are 250w ( x3=750) and im not sure about amperage... I believe 8.3a per panel... The MPPT controller is 60 amp... The inverter is 6000w & 24v....batteries are 8 six volt batteries hooked in series parallel...

 

[sunshine_eggo]

Why do you say you're having power loss overnight. What gives you that information?

 

[Jhp230gr45]

The system is entirely AIMS... Not sure if I'm overall impressed as i know technology is getting better by the year... The system is 6 years old...

The panels are 250w ( x3=750) and im not sure about amperage... I believe 8.3a per panel... The MPPT controller is 60 amp... The inverter is 6000w & 24v....batteries are 8 six volt batteries hooked in series parallel...

The power loss comes from the point when the sun starts to go down. I will lose a mostly full charge of about 26.7- 27.0v and after sun goes down i drop to about 24.8v...It seems depth and run time is longer on the sunniest days but the overall drop concerns me... This is with the system completely shut off overnight...

 

[Jhp230gr45]

Please elaborate on the components and how you observe the power loss.

Why do you say you're having power loss overnight. What gives you that information?

The voltage reading on my switch panel in the house tells me initially but I also noticed that this is not quite accurate because if i go out and actually measure at the battery bank i notice there is about a 1/2 - 3/4 volt difference... It is higher at battery bank... But the loss at night is still significant enough for concern...

It is a 2-2.5 volt drop... Ive tried disconnecting the batteries from the rest of the system to see if they drop on their own... They do about a half of volt or so just sitting overnight... Then i was thinking maybe one or more of my batteries are getting weak and that i could isolate them and figure out which one(s)... They all are the same voltage wise... They charge at the same rate and all decline at the same rate...

The batteries are 235 Ah each...

 

[SamDeleted]

I will lose a mostly full charge of about 26.7- 27.0v and after sun goes down i drop to about 24.8v...

What type of batteries are they please, sealed or flooded lead acid?



It is normal to see a drop in voltage when the sun goes down , this does not necessarily mean a loss in power. Do not confuse voltage with battery state of charge (SOC)


For example, my system with AGM batteries charges upto 29v, then when the sun goes down it drops to 26v

29v is the charging voltage
26v is the resting voltage


Both voltage figures represent a full battery , just in a different situation

 

[Bluedog225]

1. Nicely done!
2. When you upgrade, I’d go to 48 volt and LiFePO4.
3. I’ve got that genny. So far, it’s been great. I used it to build a cabin. Mine will never see gasoline.
4. The harbor freight bearings are packed with clay. Well, at least terrible grease. It’s worth is to repack and get some spare hubs/bearings before you need them. They are/were metric so it can be a little tricky. And they can change year to year as harbor freight sources from different suppliers.
5. Given your setup, you could add a side of leaning panels that would store on top if you needed the extra solar.

And welcome!

 

[Jhp230gr45]

1. Nicely done!
2. When you upgrade, I’d go to 48 volt and LiFePO4.
3. I’ve got that genny. So far, it’s been great. I used it to build a cabin. Mine will never see gasoline.
4. The harbor freight bearings are packed with clay. Well, at least terrible grease. It’s worth is to repack and get some spare hubs/bearings before you need them. They are/were metric so it can be a little tricky. And they can change year to year as harbor freight sources from different suppliers.
5. Given your setup, you could add a side of leaning panels that would store on top if you needed the extra solar.

And welcome!

Thanks! Yes, the only thing I'm disappointed in the generator is that the very next year in 2018, Champion came out with the the exact same unit except with auto-choke and Bluetooth remote start... Been trying to talk wife into letting me take that generator off, taking it to the other house as a back up and installing the newer one but I have yet to convince her... Lol...

Yes, the trailer is the 1700 lb capacity harbor freight one and is to be desired a bit but it does the job... It is not licensed for the road and only use it to move around the yard...

 

[Jhp230gr45]

What type of batteries are they please, sealed or flooded lead acid?



It is normal to see a drop in voltage when the sun goes down , this does not necessarily mean a loss in power. Do not confuse voltage with battery state of charge (SOC)


For example, my system with AGM batteries charges upto 29v, then when the sun goes down it drops to 26v

29v is the charging voltage
26v is the resting voltage


Both voltage figures represent a full battery , just in a different situation

 

[Bluedog225]

Texas allows for a license for home built trailers. Since I built if from parts supplied by HF, and lots of parts I sourced myself, I went that route. Maybe Mich does the same?

I’ve been hauling it for thousands of miles for probably 2 decades. No issues.

 

[Jhp230gr45]

What type of batteries are they please, sealed or flooded lead acid?



It is normal to see a drop in voltage when the sun goes down , this does not necessarily mean a loss in power. Do not confuse voltage with battery state of charge (SOC)


For example, my system with AGM batteries charges upto 29v, then when the sun goes down it drops to 26v

29v is the charging voltage
26v is the resting voltage


Both voltage figures represent a full battery , just in a different situation

They are Deka six volt 235Ah... The initial batteries that came with the kit were AGM but they only lasted 4 years... The biggest reason i bought them locally here was for warranty purposes... I'm kind of in the middle of nowhere!

My daytime charge on a good sunny day at peak is around 26.8 - 27.5 average and at certain points of the day even climbs above 28.0... I do have the option to add another 250w panel and did so for a period of time but it didnt seem to make much difference as i think MPPT controller may be limiting...

Then as the sun slips down i steadily have a voltage drop until total darkness where it goes to 24.8 - 25.0 resting voltage and then of course if you use power for a couple hours like we usually do at night it will slip further and stay down until the next day.... I have no choice but to be mindful of use in the evening... And gray days can even bring more of a challenge...

 

[Jhp230gr45]

Texas allows for a license for home built trailers. Since I built if from parts supplied by HF, and lots of parts I sourced myself, I went that route. Maybe Mich does the same?

I’ve been hauling it for thousands of miles for probably 2 decades. No issues.

Texas is where i spend winter!

 

[Jhp230gr45]

Im

They are Deka six volt 235Ah... The initial batteries that came with the kit were AGM but they only lasted 4 years... The biggest reason i bought them locally here was for warranty purposes... I'm kind of in the middle of nowhere!

My daytime charge on a good sunny day at peak is around 26.8 - 27.5 average and at certain points of the day even climbs above 28.0... I do have the option to add another 250w panel and did so for a period of time but it didnt seem to make much difference as i think MPPT controller may be limiting...

Then as the sun slips down i steadily have a voltage drop until total darkness where it goes to 24.8 - 25.0 resting voltage and then of course if you use power for a couple hours like we usually do at night it will slip further and stay down until the next day.... I have no choice but to be mindful of use in the evening... And gray days can even bring more of a challenge...

Sorry, they are lead acid, flooded

 

[SamDeleted]

I have no choice but to be mindful of use in the evening

What kind of voltage are they dropping to on a bad night?


Flooded lead acid are good for 50%dod , or around 11.5v~ under load

 

[SamDeleted]

Im

Sorry, they are lead acid, flooded

You've got 12kwh~ of battery, 50% discharge means only 6kwh of usable capacity


It's not a huge amount of capacity

 

[Jhp230gr45]

They are Deka six volt 235Ah... The initial batteries that came with the kit were AGM but they only lasted 4 years... The biggest reason i bought them locally here was for warranty purposes... I'm kind of in the middle of nowhere!

My daytime charge on a good sunny day at peak is around 26.8 - 27.5 average and at certain points of the day even climbs above 28.0... I do have the option to add another 250w panel and did so for a period of time but it didnt seem to make much difference as i think MPPT controller may be limiting...

Then as the sun slips down i steadily have a voltage drop until total darkness where it goes to 24.8 - 25.0 resting voltage and then of course if you use power for a couple hours like we usually do at night it will slip further and stay down until the next day.... I have no choice but to be mindful of use in the evening... And gray days can even bring more of a challenge...

Sorry, they are flooded lead acid...

 

[Jhp230gr45]

You've got 12kwh~ of battery, 50% discharge means only 6kwh of usable capacity


It's not a huge amount of capacity

No its not a large capacity... I dont usually let them go under 70%...but we usually only do a few led lights and tv in the evening...

 

[Supervstech]

How are the three panels wired?
I assume all in parallel, since all in series likely would over volt the controller.
I bet you are not quite up to full voltage for charging the bank.
What are the specs of the charge controller, and the panels?

 

[MTM98290]

Maybe it is just just voltage sag? How cold are they getting?
Nice work on a great portable setup.