New Guy With Solar Question...

[Crazy Diamond]

Ok. First off. I have a cabin in the woods that I wanted to start cheap with and learn from my mistakes. 1. I bought a set of 45 Watt Panels from Harbor Frieght for $129. on sale and a 1500/3000 Watt inverter from there also. I had to extend the charge controll to battery wire by 6 feet to get it where I needed it to go. 2. I didn't go cheap on the batteries. I bought 2 Exide Xtra 6 Volt Golf Cart Batteries at 245 Ah each hooked in series. 10 feet of 2 guage wire runs back up to the inverter. From there I have the cabin split into 2 circuits. One to the kitchen half and the rest to the living room. Estimated 200 ft of 12-2 wire in the walls. I have all led xmas, led lamp and led spot light bulbs and a 32 inch tube tv. May charge phone, vape and spotlight batteries also here and there. I don't have the tv and lights on all the time. Usually one set of xmas lights a lamp light and a spot then some tv. Now, heres what happened. I finished hooking everything up Saturday afternoon. I had charged the both batteries at my house before installation. I tested everything out. Perfecto....everything works great. Saturday night I turn the inverter on and look at the meter. 12.7 Turn the tv, lamp and outside spot on. Total of maybe 220 watts?? The tv and lamp were on for 2 hours and the spotlight was on for a total of 5 then the tv back on for another hour first thing in the morning. The spotlight is a 14 watt led btw. I check the meter again and it was at 12.2 at which point I was going out so I turned off the meter. Nice sunny day out charging the batteries I'm guessing. In the afternoon I turned on the inverter to charge my phone (crappy flip phone) and my rechargable led flashlight. In an hour they are charge so I shut the inverter off. So now its Sunday evening. Getting cloudy and dark in the cabin so I turn the inverter on to start packing up. Its on for 30 seconds and the low voltage alarm starts going off. What the hell just happened? I was told I should get a good 20-24 hrs or more running continuous before the batteries would get that low. At this point I checked the meter again and it tells me 12.4. The inverter alarm now goes off after I turned it off then back on then shuts right off. Thats when the batteries get to 10.5 volts for the alarm then 10 volts to shut it off. Somebody tell me whats happeneing here. Then bust me on the Harbor Frieght stuff. lol

[Crazy Diamond]

BTW....sorry so long. Wanted to make sure I got everything out there once. I have about $650.00 wrapped up in this for maybe 5 hours of little power.

[almac]

how many 45w panels. you need about 50 of those

[Mike90250]

stop spending $$ on harbor freight panels. It's not a good deal for lots of $ and little power. Real gear is much more cost effective and last longer.

[Crazy Diamond]

OK. I knew I was going to get bashed with the panels. Didn't have alot of money so wanted to get better batteries from the start and work off of what I started with. Figured that this was going to get me thru the weekends being they had all week to recharge. But how long will those batteries give me say if I was using 200-250 watts only at full charge. I'm already looking into different panels. Thinking I'll take those back and tell them they didn't work. Is Real Gear a brand?

[almac]

OK. I knew I was going to get bashed with the panels. Didn't have alot of money so wanted to get better batteries from the start and work off of what I started with. Figured that this was going to get me thru the weekends being they had all week to recharge. But how long will those batteries give me say if I was using 200-250 watts only at full charge. I'm already looking into different panels. Thinking I'll take those back and tell them they didn't work. Is Real Gear a brand?

get some 2nd hand grid tie panels from a demolition building supply junkyard. 250w or 300w each and get 10 of those, then you will get some useful power

[paulcheung]

get some 2nd hand grid tie panels from a demolition building supply junkyard. 250w or 300w each and get 10 of those, then you will get some useful power

I wonder what OP going to do with 10 of those second hand 250watts 300 watts panels? to charge 2 golf cart battery?

[bcroe]

OK. I knew I was going to get bashed with the panels. Didn't have alot of money so wanted to get better batteries from the start and work off of what I started with. Figured that this was going to get me thru the weekends being they had all week to recharge. But how long will those batteries give me say if I was using 200-250 watts only at full charge. I'm already looking into different panels. Thinking I'll take those back and tell them they didn't work. Is Real Gear a brand?

If you are running 250W for 4 hours, you used a KW Hour. But you supplied that from a a huge
inverter which probably isn't very efficient at 10% load, so you might have taken 1.3 KWH from
the batteries. Since the batteries have something over 2 KWH capacity, you have already pushed
them too far. Next day those tiny panels cannot bring the batteries back, so the next night finishes
the batteries. Left in that state, they will soon be destroyed.

You would do best to run everything possible directly from the batteries, esp the TV. Keep the
inverter OFF except for special needs. I have TVs here with a 12V power jack, they aren't
32", thought you were camping. After getting loads under control, figure how many KWH
a day you need and get panels that will deliver more, I would go at least double unless you
are living in a cloudless desert. Since you have batteries, you will either have to recharge
with a generator every time you don't have good sun, or shut everything down at half charge
and wait till the sun can recover a full charge. Bruce Roe

[almac]

I wonder what OP going to do with 10 of those second hand 250watts 300 watts panels? to charge 2 golf cart battery?

he will find the 2 golf cart batteries are also useless, at least with 10 x 250w panels he can run almost anything while the sun shines

[paulcheung]

he will find the 2 golf cart batteries are also useless, at least with 10 x 250w panels he can run almost anything while the sun shines

Unless is grid tie, he will need 425 amps battery bank @48 volts to support the panels.

[almac]

Unless is grid tie, he will need 425 amps battery bank @48 volts to support the panels.

not so, i use 1750w panel array with 150ah bank and can run off the panels through through this , can draw straight from the panels doesnt drain the battery at all. the charge leads run to the same terminals on the battery that the inverter leads run from

[SunEagle]

not so, i use 1750w panel array with 150ah bank and can run off the panels through through this , can draw straight from the panels doesnt drain the battery at all. the charge leads run to the same terminals on the battery that the inverter leads run from

With 1750watts of panels you run the risk of charging that 150Ah battery bank way too fast even at 48volts. Which would be around C/4.

[cmclane28]

OK. I knew I was going to get bashed with the panels. Didn't have alot of money so wanted to get better batteries from the start and work off of what I started with. Figured that this was going to get me thru the weekends being they had all week to recharge. But how long will those batteries give me say if I was using 200-250 watts only at full charge. I'm already looking into different panels. Thinking I'll take those back and tell them they didn't work. Is Real Gear a brand?

I'll start by saying I am certainly no expert. I just started dabbling recently myself. To try and answer your question though, since you never want to drain your batteries more than 50% your 2 - 6v batteries at 245 ah would probably only last you somewhere around 5 hours if you are using 250 watt hours per night. Unfortunately the 45 watts in solar panels is going to take way too long to charge them back to full before you use your batteries again. In a perfect world I you'd be looking at it taking something like 35 hrs of sunlight to recharge them from half charge. With 45 watts, even at full output, that means only about 3 amps is going into the batteries and you have to fill 122.5 ah if they are at 50%. For that size bank you're going to want several more of those 45 watt panels, but I wouldn't spend any more money on those. The kit at Harbor Freight is way overpriced for the amount of power that you get.

To get my feet wet I got the Renogy 100w solar kit from Amazon for $185, and also picked up a little 35 Ah battery so the system was somewhat balanced. I quickly found that I needed several more panels, an MPPT charge controller, and much bigger batteries to do anything very useful though.

[SunEagle]

I'll start by saying I am certainly no expert. I just started dabbling recently myself. To try and answer your question though, since you never want to drain your batteries more than 50% your 2 - 6v batteries at 245 ah would probably only last you somewhere around 5 hours if you are using 250 watt hours per night. Unfortunately the 45 watts in solar panels is going to take way too long to charge them back to full before you use your batteries again. In a perfect world I you'd be looking at it taking something like 35 hrs of sunlight to recharge them from half charge. With 45 watts, even at full output, that means only about 3 amps is going into the batteries and you have to fill 122.5 ah if they are at 50%. For that size bank you're going to want several more of those 45 watt panels, but I wouldn't spend any more money on those. The kit at Harbor Freight is way overpriced for the amount of power that you get.

To get my feet wet I got the Renogy 100w solar kit from Amazon for $185, and also picked up a little 35 Ah battery so the system was somewhat balanced. I quickly found that I needed several more panels, an MPPT charge controller, and much bigger batteries to do anything very useful though.

Good advice.

Most people underestimate both the battery size and panel wattage required to run their electric loads. Starting with expensive low wattage "battery" panels and a cheap PWM CC usually ends up with them throwing it all out and purchasing the right equipment later.

[bcroe]

Good advice.

Most people underestimate both the battery size and panel wattage required to run their electric loads. Starting with expensive low wattage "battery" panels and a cheap PWM CC usually ends up with them throwing it all out and purchasing the right equipment later.

True, and perhaps a good learning experience, before spending BIG BUCKS on a
really capable system. Anybody want some slightly used Horrible Fright panels?
Bruce Roe