Solar panels for 48v battery system

Sisuranger

New Member
Joined
Aug 20, 2021
Messages
17
Thanks ed, I appreciate the insight with the cold. I'm in embarrass which is often the coldest spot in Mn. The night Tower broke the official MN record low at -60, the official Embarrass thermometer broke at -64. I'm starting to wonder if solar panels are the right option for the amount of time I spend at my cabin and the time of year I use it. I can run my generator to charge the batteries for less than $5 per day. I stay at my cabin about 40 days per year. That's only $200 per year with no up front costs and no risk of damaging anything due to the cold. It would be next years project so I'll keep studying the benefits.
 

UpNorthMan

New Member
Joined
Dec 4, 2021
Messages
4
My cabin is newly built/project for the next few years. One of my brothers has a cabin about 1/2 mile away from mine. He uses a Honda 2200 generator himself. He built a dog house for it and works fine for him until -30F. Then he has had problems with it icing up. Quite a impressive little generator.
I have 8 gc batteries for a 220 a/h @ 48v. During Xmas/ New Years week, we get 5 days use out of it before we need sun. No fridge needed. Very common for winter in the area not to have sun. It is nice not to have to worry about gas/changing oil or the sound of a generator running. Even a quiet one. In the summer I plan on using my extra power for a ac unit. Just a couple quick thoughts.
Ed
 

Sisuranger

New Member
Joined
Aug 20, 2021
Messages
17
I tried out my insulated battery box with RV tank heaters, it worked perfectly and kept the batteries around 50F. For a short getaway, i dont want to lug batteries around but my inverter charger wont pass through power unless a battery is connected. Is there a way to make it think a battery is connected? If not, I have to look at inverter bypass switches. The threads I've read make me nervous due to backfeeding issues. Any suggestions?20211219_072734.jpg
 

Stewfish

Solar Enthusiast
Joined
Oct 20, 2020
Messages
274
Thanks to the help of this forum, I have my 48v system running. I am currently charging with a generator but want to add solar panels. I have an aims 48v/4000w inverter charger and 2 24v battery evo 100ah lifepo batteries in series. I know nothing about solar panels. I'm in northern minnesota and we have 8 to 10 hours of decent sun when it will be used the most. What do I need for panels to charge this system in a day and what are the recommended panels and charge controller? Since I also have the generator, a full charge wouldn't be necessary. I may also double my battery capacity. Thanks!

Santan Solar has the best bang for buck. On holidays they have used solar farm panels for $35 (well that was Jan 2021 atleast)

25 panels was like $225 for shipping from AZ to OR its the same costs for less than 25 bc of the pallet space it takes up. I had them send it to a freight distribution center. The center loaded them in my truck w a fork lift. That seems way easier than unloading at my house as the driver waited for me to unload 50 panels manually. It was about half the costs than door to door also.
They are known for packaging them well to prevent cracking and none of my 50 were cracked. They add all kinds of straps and stuff. Legit connectors wires, etc as well for good prices

3 in series x 8 groups = 24 panels. It charges my 32 cell 28kwa bank in half a day of sunshine and fits perfect woth the LV6548.

I went with the MPP LV 6548 for 250v 8000w input so I could string 3 panels together for a longer distance w smaller wire. Also people in Australia have been using MPP for decades w good success. I bought two of them directly from peggy at the factory via their Alibaba site. They were at my door in 3 days via dhl. I thought it was going to be 2 months via ship and was surprised when they showed up in a few days.
 
Last edited:

UpNorthMan

New Member
Joined
Dec 4, 2021
Messages
4
I don't know of any way to operate a battery less inverter. You could use a transfer switch to bypass it. I've attached a couple links to several styles. The first two are automatic and the second one is manual.
The automatic style would guarantee that you won't backfeed your inverter when you don't have a battery connected. But it will also do the same if you wanted to use your charging option if the batteries were connected.

The manual version is just that, manual. You would have to remember to flip the switch to the correct position for each use.

On thing I might add. I don't know the specifics of your system. From what I've read, most portable generators are neutral/ground bonded. If your cabin fuse box and your inverter are also individually bonded as well. You could have some major backfeeding issues. This is the reason I attached the split phase automatic version. You could possibly do something with the ground. I'm not real knowledgeable in the subject, just enough to be dangerous.

Ed



 
Top