Small system for Entry gate and Internet electronics

[cgofish]

Hi, I'm trying to design a small system for our rural property. Hour house sits about 600 ft back from the road so I'm looking at building a small "shed" or possibly just a NEMA enclosure to hold my gear. I'll need to pick up cable internet access here so I'll have a cable modem, firewall, a POE wireless bridge and a POE security camera. I'll also want to run a sigle arm gate opener like a Mighty Mule MM660 (12V). I know the firewall I'll use will draw 14W max and 11W average, I'm guessing cable modem will be about the same. the two POE devices are standard 802.3af which is 15.4w and I will most likely drive those with external POE adapters. Rounding up my wattage for all 4 devices to 16 watts gives me 64 watts, not including the gate opener.

Ideally I'd like to keep these devices powered on 24x7 as I work all kinds of interesting hours. I could probably get away with running them 20 hours a day but Question 1 is would it be worth the wear and tear on the equipment to have a timer power them on/off daily?

Question 2 is confirming this calculation which I used from Renogy's website for 24 hour equipment operation:
Recommended System Size: 341.33 WATTS
Recommended Battery Size (12V):256.00 AMP-HOURS
Recommended Battery Size (24V):128.00 AMP-HOURS

Question 3 is am I going to be better off going to a 24V battery bank and just leaving the gate opener on its own panel/battery that Mightly Mule sells? https://www.amazon.com/Mighty-Mule-E.../dp/B00GWFT2AQ

Also as a side note I currently have no power at the property. I can pick up power at the road but I'd have to drop about $2000-2500 to build a pedestal and hook up fee's. Its also one of the most expensive costs per kwh in the US...and they are expecting a significant increase in cost...and the reliability in the area is terrible so I don't even want to go there.

Thanks in advance for any help/comments. I've been enjoying reading the forum!

[Sunking]

Only thing I can say for sure is Renogy missed the battery and panel size by a mile as it requires a 12 volt 650 Amp Hour battery, or 24 volts @ 325 AH. Either way the battery weighs 450 pounds. Minimum panel wattage to support such a battery is 800 watts with a 65 amp MPPT charger at 12 volts or 30 amps at 24 volts. Take your pick

As for battery voltage, always use the higher voltage battery. Now go shopping for:

1. 4 x 200 to 4 x 225 watt panels.
2. 4 Trojan L16H batteries, 6-volt 350 AH
3. A Midnight Solar Kid 30 amp MPPT Controller.

Save your coins for new batteries every 3 to 5 years.

Easy peazy. Have a nice day.

[SunEagle]

I agree with Sunking. To me it looks like Renogy sized those recommended battery systems to be drained by 50% daily. That will shorten the life drastically.

[cgofish]

Thank you both for your input. We are having an off-grid system installed for the house and its using lifepo4 batteries. Any benefit to using that type for a small system like this?

[SunEagle]

Thank you both for your input. We are having an off-grid system installed for the house and its using lifepo4 batteries. Any benefit to using that type for a small system like this?

Just about all types of battery systems requires someone to keep a close eye on them. From what I have heard the main maintenance requirement for LiFe batteries is keeping the fluid level correct. FLA battery systems require you to keep the plates from sulfating. Sealed battery systems have less maintenance but still require some monitoring.

IMO if you decide to go with an off grid system then you have decided to add battery maintenance to your list of hobbies that take up a lot of your time.

[Mike90250]

AGM batteries = wet lead acid battery, sealed, can withstand freezing
LFP lithium battery cannot be recharged below frost point, and if you get below freezing at all, you need a heater for any lithium battery

[jflorey2]

Thank you both for your input. We are having an off-grid system installed for the house and its using lifepo4 batteries. Any benefit to using that type for a small system like this?

Reduced maintenance, primarily. LiFePO4 can last a few thousand cycles if cared for properly. However you don't really have a small system; you're looking at a pretty large battery/array.

Any reason you don't want to run a wire?

[cgofish]

I'll have a trench coming from the road for city water. I guess I could look into the cost of running a cable from the houses off-grid system in that trench back towards the road. I think it will be about a 500-600ft run. The houses off-grid system is currently designed as a 6.12KW system using LiFePo4 @ 48V (warm climate so no worries about freezing) and Conext XW 6848 Inverter with a Xantrex MPPT-60 Charge Controller. I'll have a small generator added to the system as well but I still haven't picked out exactly what I need...still reading this forum for more info on that.

Considering the $$ outlay for the main system and my lack of experience with solar I figured adding the small system out by the road would help me learn without destroying the main system but I may need to rethink the situation.

If I back hauled wire 500-600ft would it make any difference if I ran it AC after the Conext Inverter or DC from the main battery bank and then then added a local inverter? I'm not sure if that's even possible.