I have 4 lithium weize batteries in series to make 2 24 volt batteries. I live in Michigan so I have them in an old fishing cooler that I insulated and placed one rv heater. Rover solar controllers 40 amp. Transfer switch. I current am hooked to the house and run a full size refrigerator and full size freezer 24/7. Have a load center in the shed and load center in the house. I have a 1500 watt ground array made up of Renogy and Hqst 100 watt solar panels. Looking for suggestions to improve or upgrade my system. Tried to follow Will Prowse 24 volt system to charge a Tesla . Don’t know whether to get more solar panels or more batteries. Although you can always need more of them. I also thought about getting an all in one 48 volt system but I have built this from a 12 volt system and like to use what I already own.
Looking for critique on my 24 volt solar system
- Thread starter Sully7912
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chrisski
Solar Boondocker
- Joined
- Aug 14, 2020
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I am unfamiliar with your equipment.
Without knowing your kWh usage, peak loads, and how big a battery pack you want for cloudy days, hard to make a recommendation.
IMO, if yours is working how you want it, no need for an all in one. You mention going to 48 VDc for an AIO, are you planning an upgrade?
Without knowing your kWh usage, peak loads, and how big a battery pack you want for cloudy days, hard to make a recommendation.
IMO, if yours is working how you want it, no need for an all in one. You mention going to 48 VDc for an AIO, are you planning an upgrade?
I currently have a 200 ah battery pack consisting of four wieze 100 amp batteries Set up 2 pairs in series and connected in parallel. My loads are a refrigerator and a freezer and a few lights for a 3 kilowatt load in a 24 hour period. I have a transfer switch to switch to grid. With my current system I have 1500 watts of solar. I can only add 700 watts of solar panels to meet my limit. I’m just trying to figure out if I should continue with 24 volt system and add more batteries? Or change to 48 volt system. I will add the seven panels no matter what I do to help with the lack of sunlight here in the winter. Thank you for the response. Just need some input which direction to go and be smart about it
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chrisski
Solar Boondocker
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A 3 kWh load in one day, 24 volts will be fine.
A 3 kw constant load would be 48 volts.
Also sounds with the cloudy days more batteries would be nice. For planning on cloudy days, I plan on 15 watts per 100 watt panel added. I’m sure you have numbers for your area.
I have 2500 watts of panels, 3000 watt inverter, 24 volt system, 560 ah of batteries on my RV. Not to different for what you seem to have
My daily production is 1.5 kWh per day using propane heat and cooking in the winter, and a high of around 16 kWh if AC is turned on. The hot AZ summer, my rig is in storage.
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seneysolar
Solar Enthusiast
How are the panels configured? Whats the pv voltage going to the charge controllers? What are you seeing for charging current sunny days vs cloudy?
Michigan can be tough for solar in winter months. The cost benefits of trying to compensate with panels is sometimes not worth it. More batteries wont help if you cant charge them either.
I generally recommend higher output panels with higher voltage in to the charge controller. Im not sure what optimum is for the Rich controller but most mppts like a healthy split between battery and pv voltage.
I was just playing with a 6 panel array 3s2p of REC 365 into a midnite classic 150. Was getting about 9 amps to the battery (24v) on one of our gloomy michigan days (only 10% of its potential). So 60 panels is the answer?
$$$
Michigan can be tough for solar in winter months. The cost benefits of trying to compensate with panels is sometimes not worth it. More batteries wont help if you cant charge them either.
I generally recommend higher output panels with higher voltage in to the charge controller. Im not sure what optimum is for the Rich controller but most mppts like a healthy split between battery and pv voltage.
I was just playing with a 6 panel array 3s2p of REC 365 into a midnite classic 150. Was getting about 9 amps to the battery (24v) on one of our gloomy michigan days (only 10% of its potential). So 60 panels is the answer?
$$$
rin67630
Solar Enthusiast
Did you check if your panel's location is free of tree's shades?
I mean all years long...
I mean all years long...
I have 8 panels configured with 2 sets of 3 100 watt panels wired in series that are connected in parallel together and also parallel with 2 100 watt solar panels. I have a limit of 100 volts and usually get high 45 to 55 volts on charge controller.How are the panels configured? Whats the pv voltage going to the charge controllers? What are you seeing for charging current sunny days vs cloudy?
Michigan can be tough for solar in winter months. The cost benefits of trying to compensate with panels is sometimes not worth it. More batteries wont help if you cant charge them either.
I generally recommend higher output panels with higher voltage in to the charge controller. Im not sure what optimum is for the Rich controller but most mppts like a healthy split between battery and pv voltage.
I was just playing with a 6 panel array 3s2p of REC 365 into a midnite classic 150. Was getting about 9 amps to the battery (24v) on one of our gloomy michigan days (only 10% of its potential). So 60 panels is the answer?
The other string I have 3 100 watt panels in series connect to 4 100 watt panels in 2s2p configuration.35- 40 volts on controller. The highest I’ve seen on my battery monitor was 20 amps.
1.63 kWh was highest power generated in one string and 1.61 kWh on the other.
My panels are facing south. In the winter I get some shadows from some leafless trees in the early morning. By 10 am the shadow clear. The sun is lower in the southern sky in the winter. In the summer shades are much less due to the sun being over the trees that cause the shading. I should try to figure a way to adjust my panels in the winter. I’m at latitude 42 but only have panels at 32 degrees fixed on my panels
seneysolar
Solar Enthusiast
You dont want to parallel different voltage strings. This is your issue.
If 3 panels in series keeps you under 100v, then all your strings need to be 3S.
Your picture shows 15 panels so this shouldnt be a problem, one controller will have 3 strings and the other will have 2.
Thank you for your comments. I will work on changing the strings.
Just wanted to shout out to you I switched my wiring as you suggested and it made my wiring so much more straightforward. My panels are producing much better even at early morning and later evening. Thank you again for your help!!
seneysolar
Solar Enthusiast
Awesome, thats what this place is for. Happy to help!
