Revamped the Solar Setup

[Jafo]

My battery bank was aging a bit, so I decided to upgrade to the AGM type and to upgrade the system to 24 volts from 12. I still have some 12 volt equipment such as some LED lights and a couple of ham radios, so I also had to purchase a step down for those to work. Here is a list and links of all of the equipment:

• Two AGM Batteries (Sun Extender PVX-2580)
• Step down converter
• Distribution block
• 24v inverter
• 2 dual terminal fuse blocks
• 2 single terminal fuse blocks
• 2 - 30amp fuses
• 4 - 100amp fuses
• Toggle switch

If you have followed my posts at all, you know that I already have a couple 100 watt solar panels.

Here is the basic setup. I know the wiring isn't pretty, but it works:



A closer view:



Basically the setup is like this: The two panels are wired in series and come in at 24v to the charge controller which dumps to the battery until full.

From the series tied battery bank, I have mounted the terminal fuse blocks. 30 amp fuses hold the wires going to the toggle switch -> step down converter -> distribution block -> various 12v load. The second fuse in the terminal block is 100amp to the 1500 watt pure sine 24v inverter.

This provides me with ample capacity. In fact, I haven't been able to draw the battery bank below 25.4 volts yet, and that included a night we were there when it was raining so we stayed inside and watched 3 movies on a small computer monitor while also having a couple different laptops charging.

If I were to use this every day, I would probably buy 4 more panels. But since we use this only every other weekend and the occasional week straight, I probably will leave it at two.

Anyway, just thought I would share.

[Bob Rowlands]

It's always good to know that when I drop in for a quick visit flying my Bell Jet Ranger I can keep the battery nice and charged. lol

[hierony]

What measure did you use to determine that your old batteries where aging?

[Jafo]

Originally Posted by hierony

What measure did you use to determine that your old batteries where aging?

They were not giving me the same capacity as they once did. I tried sulfating them and it did improve things for a while, but not enough. I wanted the kind of capacity where I could go a week with absolutely no sun and still have over 50% charge left in the bank. During the Fall, when I spend more than just weekends up there, it is very cloudy in this part of the state due to lake effect weather off of Ontario. I need the ability to work online in order to spend that amount of time up there during hunting season.

I have since separated the old battery bank (3 135 AH lead flooded deep cell batteries) into individual batteries that I use for other things. Example, I have connected one to some old Harbor Freight panels I had laying around (45 watts) and use that to power one of my motion LED lights and the 12v water pump I use for the kitchen sink. Another I will use for similar lighting in the outhouse, etc..

[hierony]

Ah. Mildly subjective, but a good excuse to get new electronics I suppose it's kind of tricky to do good discharge cycle monitoring to determine actual capacity, especially working off solar power. Sounds like you found good uses for your older ones, though.

You got stats on your old batteries at all? Things like age, estimated total number of cycles, typical discharge depth?

[Jafo]

The battery bank was from 2012. I would imagine there were about 75-100 discharges a year, most under 50% of capacity. My old inverter would cut out aroun 11.6, and I rarely ever got to that level.

I just noticed that over time it would discharge quicker, regardless of water levels. All of the batteries seem to be doing fine in their new applications.

[Ivan]

wondered if it is worth while not inverting to AC? More efficient? The only thing I need is lights and laptop? Will be there only weekends and a week a every couple of months.. Located in New Hampshire.

[Jafo]

If you can run your laptop and lighting on DC power then no need for an inverter.

[hierony]

Agreed. The inverters pull a small bit of power just to be on, plus consume a little power just to invert. Most inverters will say they're 90-95% efficient--this means they consume 5-10% of their rated power to produce the AC waveform. I'm not sure what their standby draw is, but it isn't nothing.

I want to go straight DC for lighting & everything, but then I figured out how much lighting I wanted for fine illumination (8000-12000 lumens, or ~8-10 100watt equivalent bulbs) & realized there wasn't any good cheap lighting system to get there. So I got my 8 LED bulbs that draw ~1 amp @ 120V. Once I convert to DC I'll put the lights with the fridge & freezer on a 300 watt inverter that's always running, with a hefty ~2 KW inverter that gets switched on only when it's needed (vacuum, power tools, induction cooktop, etc).

[Jafo]

This is the inverter I use at my camp:

https://www.amazon.com/dp/B00153BE6A...rldwidecreatio

You can set it to do cycle checks on standby so it uses very little power. About every 5 seconds or so it will check if there is any draw and if so, only then will it turn on. This makes its standby draw VERY low.

I find I need AC for things like charging power tools, cell phones, shopvac, etc.. I use LED lights that were recycled from road signs for most of my lighting and they are straight up 12volt DC.