Solar Reccomendation Needed

[dg333]

I have a snomaster 56d, pretty much the only thing I am running off constantly, group 31 ody battery, looking to keep topped off when we camp for 3 days at a time, looking for a full kit,, I think I need panels, inverter and jumper style hoohups, probably will rehouse my stock battery as back up and charge that too, thanks y'all!

steve

 

[Todd & Meg]

I've been looking into this for a possible Snowmaster in the future. What I learned so far. Snowmaster claims 12 hours of run time in 24 hours. It will draw 2.5 to 5 amps. lets say 2.5 X 12 = 30 Amp hours per 24 hours.

A 100 watt panal will produce 30 amps over 8 hours in perfect conditions. Those conditions happen in the southwest part of the US, and assume no loss in wire and 100% efficiency in the controller. Which is probably not going to happen.

I haven't bought yet but I like the Renogy that is on Amazon. You'll probably need 150-200 watts in panels, I would also look at a MPPT controller over a PWM one. MPPT are in the 90% efficiency compared to 75%. You can call Renogy and they will help you size a system for your needs.

Also you just said group 31 battery. That can be 85 AH up to 125 AH, regular lead-acid, AGM, GEL? How deep are you going to discharge? Lead-acid should only be 50%, high end AGM can be 80%. The VMax battery I have has minimum watt solar panel size to recharge with. If your panel is to small you might not be able to fully charge the battery, and batteries like AGM do not like not being charged to full.

Do you plan to stay in one spot for 3 days or do you move to different sites every day? I decided to not go with solar for now because we rarely stay more that a day at one place two at the most. I went with a Ctek DC to DC charge that will fully charge my battery from the alternator while driving. I should be able to charge the battery at 20 amps, so in two hours I can replace the 30AH used by a Snowmaster, rain or shine it doesn't matter. Also the Ctek has a MPPT solar controller built in so I can add panels latter and not have to change anything. Just another option.

Good luck.

Todd

 

[Mark D]

Here is my thread:

Solar Power-interesting read
https://www.overlandbound.com/forums/index.php?threads/Solar-Power-interesting-read.21717/

 

[dg333]

It’s an odyssey group 31 agm, I ran the snowmaster for about 12 hours and the volatile was at like 11.8 at that point, not sure if that helps, odyssey also said 30 amps for charging I think

steve

 

[Todd & Meg]

It’s an odyssey group 31 agm, I ran the snowmaster for about 12 hours and the volatile was at like 11.8 at that point, not sure if that helps, odyssey also said 30 amps for charging I think

steve

It looks like that battery is 100 amp hour. Was it fully charged with an AGM charger? A fully charged AGM battery should be above 13 volts. At 11.8 you used 80% of the battery. Also did you have anything in the fridge when you did the test? Was it pre chilled? If not do the test again and fill it up with bottles of water or cans of your favorite beverage. Start the test with the fridge already cold by running on AC. If you are using the freezer have some frozen water bottles to put in there too. You want to have the fridge filled like you would while using it to get a good test.

Todd

 

[dg333]

It looks like that battery is 100 amp hour. Was it fully charged with an AGM charger? A fully charged AGM battery should be above 13 volts. At 11.8 you used 80% of the battery. Also did you have anything in the fridge when you did the test? Was it pre chilled? If not do the test again and fill it up with bottles of water or cans of your favorite beverage. Start the test with the fridge already cold by running on AC. If you are using the freezer have some frozen water bottles to put in there too. You want to have the fridge filled like you would while using it to get a good test.

Todd

I basically pulled out of the box (battery and fridge) and went straight to camp ground, I do have a trickle charger but I don't know if it is agm specific, it was for my boat, best bet sounds to get the solar rig and top off battery? Fridge was prechilled to a point, I was kind of messing around with it seeing how fast it would get cold, maybe I'll toss it back in the truck tonight and see what it reads in the am

also the fridge ran without having the truck turned on from about 2pm to 9am, I was off with how many hours I had it running


steve

 

[dg333]

this is the exact battery, I put 3/8 threaded to stud bolts on it too

steve

 

[dg333]

so I just plugged in my snowmaster and battery says 12.8, guess I need to top this thing off?

steve

 

[Mark D]

so I just plugged in my snowmaster and battery says 12.8, guess I need to top this thing off?

steve

Depends, if that is the resting voltage and what the air temperature is. This is a rough guess for a resting voltage:

 

[dg333]

sick I am gonna save that to my desktop!

steve

 

[Mark D]

sick I am gonna save that to my desktop!

steve

You should read the article. I posted the link here here a few pages ago. Tons of great info about batteries, solar, usage, etc.

 

[dg333]

yep sure did! I like the break down on inverters, still sussing out what everthing means!

steve

 

[dg333]

20 hours in the truck empty running and went from 12.8 to 12.2

steve

 

[Todd & Meg]

Here is the state of charge chart for Odyssey batteries.



The numbers you posted today shows you used 50 Ah in 20 hours. That is 30 watts per hour. Not sure where you live but I'm guessing east coast, you get 4 hours of average sun per day. So you would need 185 watts of panels or 2-100 panels. With a PWM controller. Going to a MPPT controller you could get away with 150 watts or panels but you are undersized.

That doesn't include any other power draw on the system. You didn't say what kind of inverter you want to run or what you plan to run off the inverter. But I would bet adding an inverter with even minimal draw will mean adding another battery.

Another thing to keep in mind is the 4 hours of sun is prime mid day sun. Not pull into camp at 4:30 and put out the panels till sunset 4 hours.

Make sure your charge has an AGM setting, you need to charge your battery at 14.7-14.9 volts to get a full charge. Chargers without an AGM setting are more in the range of 12.3-12.4. Under charging an AGM is just as bad as running it too low. I am using a CTEK charger, Noco are good also. Are you using the battery for anything else?

Todd

 

[dg333]

Here is the state of charge chart for Odyssey batteries.



The numbers you posted today shows you used 50 Ah in 20 hours. That is 30 watts per hour. Not sure where you live but I'm guessing east coast, you get 4 hours of average sun per day. So you would need 185 watts of panels or 2-100 panels. With a PWM controller. Going to a MPPT controller you could get away with 150 watts or panels but you are undersized.

That doesn't include any other power draw on the system. You didn't say what kind of inverter you want to run or what you plan to run off the inverter. But I would bet adding an inverter with even minimal draw will mean adding another battery.

Another thing to keep in mind is the 4 hours of sun is prime mid day sun. Not pull into camp at 4:30 and put out the panels till sunset 4 hours.

Make sure your charge has an AGM setting, you need to charge your battery at 14.7-14.9 volts to get a full charge. Chargers without an AGM setting are more in the range of 12.3-12.4. Under charging an AGM is just as bad as running it too low. I am using a CTEK charger, Noco are good also. Are you using the battery for anything else?

Todd

thinking of this
renogy 200 watt suitcase kit, wont let me put in link

steve