Solar Power Part 2

[Sneakers]

So it's been a bit over 2 years since the Solar project. It was (still is) a great success, but I got the urge to build a new portable system, a little lighter, more capable, better hardware. I really like the old system I built, but the 100Ah lead-acid battery is contained within the case, so it's heavy and a bit awkward. I have an old camera case I no longer use, so I'm building a new system containing only the electronics and keeping any batteries external. Also designing it to use both lead-acid, and LiFePO4 batteries which are significantly lighter and have a better power output curve.

Got a few parts today, a Victron solar charger with BlueTooth, and a shunt with power meter. The on/off switches I used last time were poor quality (had to epoxy them together so they didn't separate..) so I ordered some from BlueSea marine. Watertight and multiple mount options, rated at 300 amps. Overkill, but I'm designing-in more capability for the future. Increasing the solar panel input connectors and wiring from 15A to 20A, the inverter from 1000w to 2000w.

The Victron controller is nice. Set it up on the bench, picked it right up on the Android phone app. You can configure any option via the app and get current values, history, and it even graphs the volts/amps/watts.

So... one more project... Like I don't have enough to keep me busy.

 

[PrchJrkr]

What kind of output do you get from the original setup? You may have said it, and I'm too slow to realize it. What type of devices have you powered with it and how many amp hours does it store? Blue Sea does distribute quality merch.

 

[Sneakers]

Solar Power

Been doing a lot of research on "off grid". I'm not looking to go off grid, but I do want to do some camping in remote areas, but still want the luxury of cold drinks and a charged cell phone/laptop. The price of components has come way down, a decent 100 watt solar panel can be had for around...

forums.somd.com

The original has a 1000W 120VAC inverter on a 100Ah 12VDC AGM battery with a 270W solar panel @24VDC nominal. It was designed to run a small fridge, lights and USB rechargers. A fridge would run at least 36 hours without solar. I designed that one to easily add external batteries to increase the Ah. The fridge could draw 1200W on startup surge, so I was pushing my luck. Manufacturer said the inverter can handle a 2000W surge, but for only 40ms, basically nothing.

The new system will start off with the same 100Ah lead-acid battery, but will eventually up it to 1000Ah LiFePO4. The 2000W inverter (yet to be spec'd) can handle 2 house fridges plus lights, etc..., if you stagger the startups. The new solar controller can handle 100VDC and 35A from the solar panels, currently only have the one 270W 24VDC panel. Again, the intent is small and portable, so longer run times is the goal vs. high power demands.

 

[Gilligan]

Will the new panels fit the frame the old ones are in? I’m keen to see how this one comes out...want to put something like that on our camping buggy.

 

[Sneakers]

Will the new panels fit the frame the old ones are in? I’m keen to see how this one comes out...want to put something like that on our camping buggy.

Haven't spec'd out any new panels, using the same one I had. Just building the solar generator to be able to accommodate more/larger panels if I want. The Victron can handle 3000W (100VAC @ 30A) , but designing for 2000W (100VAC @ 20A) to keep wire sizes down.

Had a bit of trouble getting the panel out of the frame. It had been sitting in there since last fall and seems to have gotten a bit of oxidation. Took a pretty good effort to remove the panel. Could probably use looser tolerances.

 

[Gilligan]

Had a bit of trouble getting the panel out of the frame. It had been sitting in there since last fall and seems to have gotten a bit of oxidation. Took a pretty good effort to remove the panel. Could probably use looser tolerances.

Take that up with engineering dept. The fab shop just followed the drawings.


Clean the oxidation off with stainless steel wool and then wax the surfaces with good old fashioned carnuba car wax.

 

[Sneakers]

Take that up with engineering dept. The fab shop just followed the drawings.

Sometimes they do.... sometimes.

 

[Gilligan]

Sometimes they do.... sometimes.

We try to adhere to MIL-TD-D41 at all times.

 

[Sneakers]

We try to adhere to MIL-TD-D41 at all times.

...and a wonderful job you do.

 

[kom526]

I need to make my MechEng kid read this and decipher for his Cro-Magnon dad.

 

[Kinnakeet]

So it's been a bit over 2 years since the Solar project. It was (still is) a great success, but I got the urge to build a new portable system, a little lighter, more capable, better hardware. I really like the old system I built, but the 100Ah lead-acid battery is contained within the case, so it's heavy and a bit awkward. I have an old camera case I no longer use, so I'm building a new system containing only the electronics and keeping any batteries external. Also designing it to use both lead-acid, and LiFePO4 batteries which are significantly lighter and have a better power output curve.

Got a few parts today, a Victron solar charger with BlueTooth, and a shunt with power meter. The on/off switches I used last time were poor quality (had to epoxy them together so they didn't separate..) so I ordered some from BlueSea marine. Watertight and multiple mount options, rated at 300 amps. Overkill, but I'm designing-in more capability for the future. Increasing the solar panel input connectors and wiring from 15A to 20A, the inverter from 1000w to 2000w.

The Victron controller is nice. Set it up on the bench, picked it right up on the Android phone app. You can configure any option via the app and get current values, history, and it even graphs the volts/amps/watts.

So... one more project... Like I don't have enough to keep me busy.

What do you do with the batteries when they no longer work

 

[Sneakers]

What do you do with the batteries when they no longer work

The lead acid batteries can be turned in anywhere that takes batteries, or taken to a metal salvage yard. I've gotten some good money there.

I don't have any lithium batteries yet, but they have a minimum 20 year warrantied life, so hopefully by the time they expire there will be a way to recycle them.

 

[Sneakers]

Been a long time getting back to this, but made some progress.

Found the camera case was just not the right shape, so got a plastic toolbox from wallyworld. Mounted up most of the hardware today, wiring is next. The design didn't have an internal battery to save on weight, but there is room for one motorcycle sized battery, enough for quick power.

My home network is down. I'll post some pics if and when it comes back up.

 

[black dog]

Take that up with engineering dept. The fab shop just followed the drawings.


Clean the oxidation off with stainless steel wool and then wax the surfaces with good old fashioned carnuba car wax.

Ever use Boeshield T9 or other Boeshield products?

 

[Sneakers]

Ever use Boeshield T9 or other Boeshield products?

Never heard of it.
The original plan was to get everything powder coated, but the local powder coat place was backed up for months, and I never got back there.

 

[black dog]

Never heard of it.
The original plan was to get everything powder coated, but the local powder coat place was backed up for months, and I never got back there.

Excellent stuff, ive used it on outboards, sailboat diesel, winches, shop equipment and so on for 20?+ years now. Expensive but worth it...

 

[black dog]

I think I used to buy it at Posners.

 

[Sneakers]

 

[Sneakers]

I never did spec out a 2000w inverter, so I used my old 750w inverter, but left room for a much larger one when I finally decide what I want.

 

[Sneakers]

Pretty much done. Hooked it all up and ran a few tests, looks good. Weak sun, panels had partial shade, but I was still able to generate 180 watts while pulling 15 amps from the battery.



Much cleaner design, and the wiring/fusing is good for 150 amps, so just shy of 2000 watts. Without an internal battery, it's much lighter and more transportable. After the holidays I'll look for a 1500-2000 watt inverter.