Thinking small 700W 110Vac Workstation (first Solar project)

[TommySr]

It seems each year I feel compelled to take on a new project (task).

sometimes it's snow removal

Sometimes it's Automatically mowing grass

one time it was growing sweetcorn

the electric bike was hours of entertainment




My current task is to power my home workstation with Solar.
I have 5 computers with monitors of different sizes 52" to 8"
a few soldering irons, and some lighting. with everything running
the wattmeter said 400watt.

The plan is to have 700watts available 24/7

I got 16 of these


the battery banks are 24V, the plan is to have 800Ah total in 3 banks of different chemistries.

the system controller and telemetry information is going to be from an Arduino Nano.

because a number of the computers are running under test, if the battery banks fall below
21.5Vdc the Arduino starts a Powermax PM3-20-24 battery charger until the charging amps
drop below 5 amps.



The Task is not to save money or the world, it's about the hours of entertainment.

Tommy
SE Wisconsin
English is not my first language, code is.

 

[Culchee]

It seems each year I feel compelled to take on a new project (task).

sometimes it's snow removal

View attachment 185777

Sometimes it's Automatically mowing grass

one time it was growing sweetcorn
View attachment 185780
the electric bike was hours of entertainment

View attachment 185781


My current task is to power my home workstation with Solar.
I have 5 computers with monitors of different sizes 52" to 8"
a few soldering irons, and some lighting. with everything running
the wattmeter said 400watt.

The plan is to have 700watts available 24/7

I got 16 of these
View attachment 185786

the battery banks are 24V, the plan is to have 800Ah total in 3 banks of different chemistries.

the system controller and telemetry information is going to be from an Arduino Nano.

because a number of the computers are running under test, if the battery banks fall below
21.5Vdc the Arduino starts a Powermax PM3-20-24 battery charger until the charging amps
drop below 5 amps.



The Task is not to save money or the world, it's about the hours of entertainment.

Tommy
SE Wisconsin
English is not my first language, code is.

Good luck with your latest project Tommy..

 

[sunshine_eggo]

Confused...

With everything on, you're consuming 400W. Why do you want 700W 24/7 when 400W 24/7 seems to be what you need?

Whatever the case, 235W * 16 = 3760W.

Use PVWatts from link #1 in my signature to determine what your PV availability is.

400W 24/7 = 9.6kWh/day
700W 24/7 = 16.8kWh/day

In summer, you'll easily do 400W, maybe 700W. In winter, you'll struggle to get 400W.

800Ah * 24V = 19.2kWh

Definitely don't like "3 banks of different chemistries" unless you REALLY know what you're doing.

There are inexpensive battery monitors that have relay trigger capabilities to automatically engage based on target voltage conditions.

A 20A 24V charger isn't enough to keep up with your 700W loads.

 

[TommySr]

Whatever the case, 235W * 16 = 3760W.

sunshine_eggo, I do have some environmental issues that limit sun exposure. (lots of large trees)

There are inexpensive battery monitors that have relay trigger capabilities to automatically engage based on target voltage conditions.

very true, but I can't see the fun in that. the same could have been said about the bike project, it cost me more
to make one then I could buy one. practicality never seems to be a topic in any of my projects.

Definitely don't like "3 banks of different chemistries" unless you REALLY know what you're doing.

each of these bring different challenges and benefits to the project.
a good example is Lithium Ion, with the ability to bulk charge at 100A for 3000 cycles
but has some limitations.
over coming them limitations is what makes the task interesting.
with Lithium Ion there are 2 costly issues, temperature and very high current (fire) .
the plan for each of these issues right now is a kiln. I have a 40watt incandescent light
running inside a kiln, even here in Wisconsin that one light bulb is able to keep the temperature
inside the kiln above 60degF.



I believe by this spring I'll have a better idea of which chemistry is best for my project.

 

[TommySr]

With the weather as it is, seems a good time to look at the BMS.

I was thinking of using a Arduino Nano as the controller because of it's low current draw and small size, but
after finding one of the devices below I'm now planning to use a Arduino Mega.





I plan to give the BMS it's own power source. (1 230W panel, 3S3P 3.7V 8Amp cells)


I also found one of these boards that read 4 thermocouples for very accurate temperature reading.



the voltage sensors I plan to use has 16 different input addresses, my lipo pack is 7s, the Arduino pack is 3s that still gives me
6 for the LifeP04 pack.

Tommy
SE Wisconsin
(New to Solar)

 

[TommySr]

Good luck with your latest project Tommy..

Culchee, I cheat. I don't set a time limit for a project.

but I do convolute things. like making a BMS ($350 parts and countless hours writing code and soldering wires ). when I could spend $25 on amazon for a 7S 100Amp BMS.


Tommy
SE Wisconsin
(Very new to solar)

 

[TommySr]

after looking at some topics on BMS failures that ended very badly.
I'm thinking of putting these at the battery end of each BMS lead.

in case a mouse think the balance lead insolation taste like chewing gum.

 

[TommySr]

crappy day for solar, but good day to find a box and solder up some voltage sensor boards.





I was able to replace the 40watt incandescent light bulb inside the kiln with at 20Watt bulb and it
can still keep the inside temperature above 60degF



Tommy
SE Wisconsin

 

[TommySr]

Starting to get telemetry information from the DIY Arduino BMS



working on remote monitoring.






The BMS is going to be located outside, using Bluetooth to get information from the BMS to inside home PC.


Tommy
SE Wisconsin

 

[TommySr]

with it being too cold to work on 700W solar project, I'm turning my attention to an old project.

adding Lifeop4 batteries to my snow shovel, and charge them with the (4) 230W panels I currently have
pointed at the sun (24Vdc@16Amp) because the snow shovel doesn't need to work each day the (4) panels could
charge the (2) 24Vdc 200Ah LifeP04 batteries.



when I first started building the snow shovel 2010 flooded batteries is all I knew, but they did not work as needed.
so I added a 6hp gas engine powering a 24Vdc alternator to supply the power needed.



it did give me the power to run the snow shovel as long as there was gas in the tank, but it made it very noisy.
I hated how loud it was.

so I'm now pulling the engine off and adding 24Vdc 400Ah LifeP04 batteries.
if I can get 3 hours operating time I'll be a happy camper.




the below image is how I control the snow shovel (5) cameras.




Tommy
SE Wisconsin

 

[TommySr]

If they work half as good as they look, 2 of them should be able to run my workstation for 24Hr
or my snow shovel for 3 hours.

when turning the snow shovel it draws 100Amp
when lifting 400lb it draws 40Amp
Dumping the bucket draws 20Amp

 

[TommySr]

with the motor installed



replace the flooded lead batteries with LifeP04 24V 200Ah 2P







Without the motor

 

[TommySr]

it is kind of interesting to see how projects change over the years.

started in 2010 as a EV snow plow and mower.







updated in 2016





then in 2018 my granddaughter started a lawn mowing business so the project turned to only snow removal.

 

[TommySr]

unintended and unforeseen consequences of changing form flooded to LifeP04 batteries
with the flooded I could get 10 years of use out of the gearboxes, with flooded it was mostly
the motor brushes that needed replacing from time to time. now I got 2 stripped gearboxes.

 

[Andrewr05]

Too much power going to them?

Probably before those lead acid batteries would draw down when the motor called for a big load and you would get a lot of voltage droop, stalling the motor.

Now you have a lot more power on tap, so the motor just goes and goes regardless.

 

[Andrewr05]

That's a pretty awesome outside of the box project too, I love it!

 

[TommySr]

Now you have a lot more power on tap, so the motor just goes and goes regardless.

time to find/make stronger gearboxes, because I'm not going back to flooded.

 

[Andrewr05]

time to find stronger gearboxes, because I'm not going back to flooded.

I'm thinking you could find some sort of current controller that would only allow a certain amount of amperage to be pulled.

 

[TommySr]

I'm thinking you could find some sort of current controller that would only allow a certain amount of amperage to be pulled.

it is possible to change the speed controller to one that gives me current limiting option, but that would require
software changes also, the current software has been running for over 10 years without issue, so the lowest fruit
would seem to be the gearbox.

I could be wrong... I currently have a single axis speed controller with current limiting on the bucket lifting axis
it's only 50Amp which should also help. I just need 2 more for the drive wheels.

Thanks for the wakeup!

 

[Andrewr05]

It's worth a shot.
But it depends on the price, if you can get beefier gearboxes for less than you can get the different motor controllers then that might be a better option.