Gate opener project

DocWattDocWatt Registered Users Posts: 7 ✭✭
[Disclaimer: I've searched and cannot find info on this on the site, but please advise if someone knows this has been discussed before.]

I am installing a Ghost Controls operator arm on a new gate I just installed. The system is designed to be AC powered, but they do sell a solar option, however, even they say to upgrade the included 10w panel to a 30w and if you do so...they say to get a deep cycle battery, negating their battery box with two 7ah batteries completely. Nice, right? So basically they sell a "solar looking" set-up that is backed up by AC.

In my project, I do have access to AC, but it's to much of a hassle and I want to try to get this 100% solar, even if it's a bit over-engineered to do it. I've seen a few things Woody has posted on micro solar systems and I feel like that's close to what i'm looking for, but the cold usage complicates a bit (will be used year round, but obviously it's easier in the warmer months).

My plan: I have the Ghost Controls TSS1 (operator arm and control panel only) and I have a Renogy 30W panel. I know I may need a charge controller (suggestions welcome), but the circuit board that comes with the unit will rectify up to 30w so it can serve as the controller for my panel (in theory). The main issue i'm trying to resolve in my non-fully-solar-educated mind is what to do for the battery. I'd prefer to mount it near the panel and operator, so lithium is attractive (mostly because of the weight), but this will always be outside (in some sort of enclosure i'll build...perhaps with some help/suggestions), but while I live in N.C., USA (zone 7B) and it won't be below 10 deg F often, that's below the normally enjoyed "above 32 deg F" charging zone for lithium. I know I can discharge it below that, but i'm guessing that is not a great plan for a winter of use...discharge as needed, recharge only when above freezing.

From what I understand the draw would be around 3-5 amps for the gate operator per cycle, with an additional 4 amps used for five seconds with the lock = 9 amps per activation; 18 amps per full cycle (open and closed). The draw on the operator will of course change a bit as that is estimated, not measured under load with my particular gate (nothing super heavy thankfully). There is also a 25 milliamp continuous draw for the circuit board.

So, do I go overboard and super size the battery AH to cover the inefficient nature of running the system in the cold? (As in have a 500-1000AH battery that can just recharge when it's warm enough and try not to discharge to far between charges.) Should I go just above what I need battery wise and then run a thermostat controlled warmer? Anyone have experience with the Kilovault HLX, LiFePO4 Blue batteries (BMS with built in heaters), or the Winston LiFeYPO4? Should I skip lithium all together and go AGM or gel, which still have some cold issues of their own?

Any guidance and direction to help me avoid spending way to much if there is a better option is appreciated.


  • BB.BB. Super Moderators, Administrators Posts: 32,612 admin
    For searching on our forum (or any website), you can use the "site:" tag to limit searches to a particular website. For example, just plug the following into Google/Duckduckgo/etc. search engine:
    • solar powered gate opener
    Here is one thread here that talks about AC based gate opener and how to size the panel/battery/inverter/etc. to run it...

    With any "reasonable" solar system design--Need to know as much as possible about the equipement (wattage, hours of use per day, standby current), rough location, etc. so that we can help do a paper design of a system that will meet your needs.

    The AC systems--You have the losses of running an AC inverter (something like 6-20 Watts +/-)...

    The DC version can save you electricity (no inverter, lower power consumption for systems designed to run from batteries, etc.).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DocWattDocWatt Registered Users Posts: 7 ✭✭
    edited December 2021 #3
    Thanks for taking the time to respond Bill.  I tried the search and my own post comes up, but not much more.  I had already read your posts to panapat on a similar topic, but i didn't understand enough to get what I need as he was going AC.
    I tried to provide as many specs as I could.  I gave equipment specs, location (zipcode is 27407 if that's better), etc.  Some of what you asked I don't even know how to determine, so i'm obviously new at this.
    I honestly don't know how to know for sure if this opener is AC or DC, but their setup allows you to run it off a 7ah battery from a panel, so i'm guessing DC?  The circuit board that comes with it may function as an inverter, but as far as i understand it it is really a charge controlled for the panel and you don't have to have any AC power (I know this), it's just there to charge the batteries if the panel does not get enough exposure, etc.
    Hours of use will be 2-3 hours or less per day (and that's an atypical max).  I'd expect 10 open close cycles total, mostly open and leave open and then close and leave closed a few (2-3) times per day.  Each open close cycle should be under two minutes to complete.  Let me know what other info you need.
    I'm a quick learner and willing to do the leg work, I just don't know where to go and I don't want to spend $2500 on something that I won't tap the potential of with just a gate opener if I don't have to.
  • DocWattDocWatt Registered Users Posts: 7 ✭✭
    I did find something helpful you commented on in 2009 Bill.  Still not exactly where I am thinking/what I need, but helpful to read.
  • mike95490mike95490 Solar Expert Posts: 9,572 ✭✭✭✭✭
    I think you will find it easier to trench and run 400' of AC cable to the gate, than try to convert an AC opener to run off solar.

    This is the model I have   LiftMaster_RSW12V_gate opener, purpose made, 12VDC, DC control boards.
    It is not in the same class as the $200 mighty mule.  This will go for weeks on it's 20A battery
    You have to mount it on a concrete pad and align things properly

    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    gen: ,

  • DocWattDocWatt Registered Users Posts: 7 ✭✭
    edited December 2021 #6
    Thanks for the comment Mike.  I already have the G.C. system and do plan to use it.  I also do not have the ability to trench as there are obstructions on all sides, so solar, again, is the plan.

    Like I said, while I can't confirm 100% AC or DC on the system, I know you can run it fully off of a battery that is charged by a panel, so it sounds like what you're describing.  My only question is what battery type I should choose and how to figured out the needed AH for my setup.  I'm also trying to figure out how to work around the cold and recharging aspect, because I know that's a bit of an issue, but I don't know enough about how to work around it.

    Sorry if my question wasn't direct enough, I was just trying to give ample info.
  • VicVic Solar Expert Posts: 3,145 ✭✭✭✭
    We have used an Apollo (now Neat,  IIRC),  that seems to be designed for Solar,  but with AC power backup capability ...

    Have always used a group 27,  or 31,  12V Flooded Trolling motor battery  (approx 80 - 100 Ah),  these batteries would normally last,  with no issues for ten-ish years.  Our coldest temperatures are generally 15 - 20 degrees F.  Usually used a 25 - 30 watt solar panel,  and never had a battery freeze.  These gates only see three,  to five cycles per day.

    With that battery size,  and solar panel,  you almost do not need any charge controller,  just check the water level a couple times per year.

    YMMV,   Vic
    Off Grid - Two systems -- 4 SW+ 5548 Inverters, Surrette 4KS25 1280 AH [email protected], 11.1 KW STC PV, 4X MidNite Classic 150 w/ WBjrs, Beta KID on S-530s, MX-60s, MN Bkrs/Boxes.  25 KVA Polyphase Kubota diesel,  Honda Eu6500isa,  Eu3000is-es, Eu2000,  Eu1000 gensets.  Thanks Wind-Sun for this great Forum.
  • BB.BB. Super Moderators, Administrators Posts: 32,612 admin
    edited December 2021 #8
    OK, the spec is a 2x7 AH battery (presumably 12 volts). You may be able to call it "AC" powered--If it has an AC battery charger option (and uses battery for backup).

    Looking at the website, is this what you have?

    And we have the question of 1 or 2 openers...

    That is a 12 VDC actuator, and according to the manual:

    SPECIFICATIONS Compliance: The operator is system certified to be in compliance with UL325 Standard, 7th Edition System Operating
    Voltage: 12V DC
    System Battery Type: 12V DC Deep Cycle Marine Battery Required (not included) or Battery Box Kit (ABBT2) (not included)
    System Current: 1-2 Amps is typical when active. Standby is 20 milliamps
    Operator Arm Maximum Stroke Distance: 20 Inches Maximum Gate Length: 20’ Operator Opening Speed: 90 degrees in approximately 15 seconds Maximum Operator Opening Range: 110 degrees
    Linear Actuator Operating Temperature: -5°F to 160°F
    Now... For gate openers, they typically only overate for 5-15 seconds (open) and other 5-15 seconds (closing) per cycle. When not operating, the above takes only 0.020 amps (running the radio receiver(?).

    So, being used 2-3 hours per day does not tell me how many cycles per day... 10 Cycles (total) per day? Or more than that?

    When we measure energy (Watt*Hours) or "amperage" usage (Amp*Hours)... We look at both the current and the time--In hours for solar and general power (in physics, we used Watt*Seconds--But that is a "huge" number when translated to powering a home/industry, so use Hours instead).

    For example. In Amp*Hours (at 12 VDC assumed), say 4 amps @ 15 second cycle time:
    • 15 Seconds / 3,600 seconds per hour = 0.004 hours per cycle (open OR closed) [fixed typo]
    • 0.004 hours per cycle * 4 amps = 0.016 AH per cycle 
    • 14 AH battery * 50% recommended cycling depth of discharge (for longer life) = 7 AH "useful" output
    • 7 AH / 0.016 AH per cycle = 438 cycles
    • 438 cycles / 2 (open close cycles) = 219 open/close cycles
    • 219 open/close cycles / 5 days without charging (no sun) = 44 (open/close) cycles per day)
    With lead acid batteries, suggest generally 2-3 days between charges--5 days at the outside (longer battery life). Choosing an AGM (type of lead acid battery) would be better (deep cycle type). AGM are sealed and do not need to add water every 1-6 months.

    So--From a basic (and conservative--4 amps @ 15 seconds cycling may be more energy than really needed)--14 AH @ 12 volt AGM battery is a good fit. As always, knowing how to manually cycle the gate (no sun, failed charging) is also needed.

    Now charging... If we take 44 open/close cycles per day as the needed energy:
    • 44 full cycles per day * 2 * 0.016 AH per "1/2" cycle = 1.4 AH per day (at 12 volts)
    • 1.4 AH * 18 volts Vmp (solar panel working voltage) = 25 Watt*Hours per day
    There is also the power used by the radio receiver: 20 mA standby:
    • 0.020 Amps * 24 hours * 18 Vmp solar panel = 9 Watt*Hours per day for receiver
    • 25 WH for actuator + 9 WH per day for receiver = 34 WH per day (this is based on a PWM solar charge controller)
    The mfg has a solar harvest chart with cycles per day per 10 Watt solar panel:

    Or we can use a solar insolation program and estimate the amount of sun you get per day. Say Greensboro NC, fixed panel, facing south:

    Average Solar Insolation figures

    Measured in kWh/m2/day onto a solar panel set at a 54° angle from vertical:
    (For best year-round performance)

    Taking worst (long term average) hours of sun per day:
    • 34 WH per day * 1/0.9 AGM battery efficiency * 1/3.44 hours of sun per day (December) = 11 Watt array minimum
    For solar loads that you want to run 24x7x365, suggest that you take the above and mutliply by 2x (for bad weather, dust on panels, etc.)
    • 11 Watt panel * 2 = 22 Watt minimum suggested panel
    So your 30 Watt panel would be fine.

    A simple PWM charge controller would be rated at:
    • 30 Watts * 1/18 volts Vmp panel * 1.25 NEC derating for solar = 2 Amp PWM charge controller minimum
    MorningStar makes lots of solar charge controllers with good reputation. From our host (Northern Arizona Wind & Sun):

    Morningstar 4.5 amp, 12 volt solar charge controller

    But you are welcome to buy your own elsewhere...

    Anyway... That is how the math works.

    I am not sure I have the correct gate opener for you--But you can see how the math works and a 14 AH @ 12 volt AGM battery would work nice and should last you 3-5 years.

    Li Ion is interesting--But a lot more expensive and cannot charge below ~40F. And they should have a BMS (battery management system) to protect cells against over/under charging (and balancing cells).

    I am not a Lithium Ion battery expert... So I really do not have any suggested suppliers to recommend. Others here may be able to help you with that. Lead Acid batteries are much more "forgiving" with overcharging/cell balancing vs Li Ion, and much cheaper than Li Ion (on average).


    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DocWattDocWatt Registered Users Posts: 7 ✭✭
    edited December 2021 #9
    Thank you Vic.  That is helpful to know for sure.  Perhaps I'm just complicating things in my head a bit, but I never thought about a flooded as there's so much push for "newer tech." and everything I've read said AGM or Li Ion (not that they said to avoid FLA, just skipped it I guess).  It's great to hear from someone achieving a similar thing to what I hope.

    Bill, I am still digesting and re-reading your last post.  Incredible detail you've given me.  I really, REALLY, appreciate you looking into and helping with this.  I'll write back more as I follow those leads.  Yes, the first link is to what I have if you click solar, except I bought it without their batteries or panel as they said i'd need to upgrade to a 30 w (10w was included) and they said to go with a deep cycle battery, so that negated being able to use either the panel or batteries that came with the kit.

    Bill, by "one or two openers" are you meaning the remote opener control or the operator arm (what they call it) opener?  I'm guessing you mean the arm; it's a single arm system thankfully so that'll use a bit less in theory.
  • BB.BB. Super Moderators, Administrators Posts: 32,612 admin
    Yes, one or two "arms" (one or a pair of gates)... Your amperage estimate sounds on the high side for a single arm system--That is why I asked.

    Sorry, the "options" and being unclear may have made my posting a bit on the "confusing side"--That is why I try to figure out exactly what you have or what you want, and then discuss that in detail--It usually makes things a bit less confusing.

    One factoid I did not mention... For lead acid (and it works pretty well for all battery types)--Rate of charge. Deep cycle lead acid batteries "like 10-13% rate of charge"--And that usually works out pretty well for full time off grid solar powered systems with "good sun".

    For lightly used systems, you can get away with 5% rate of charge (using the 20 Hour capacity AH rating for battery). So, for a 30 Watt panel, that would be roughly:
    • 30 Watt Pmp / 18 Volt Vmp = 1.67 Amp Imp
    • 1.67 Amps * 1/0.05 rate of charge = 33.4 AH @ 12 volt battery
    So, ideally, with a 30 Watt panel, try not to get a battery that is >>33 AH capacity--Or it may chronically under charged (especially as the battery gets old and has higher self discharge). This design has a lot of "extra capacity" to operate during longer periods of bad weather or a family weekend of lots of cycling.

    A battery anywhere from 14-33 AH (approximately) on your 30 Watt panel seems like it would work well, unless the gate is heavily used (more than ~44 open/close cycles per day. And you may get quite a bit more cycles per day if the current is 1/4 and cycle time is much less than 15 seconds.

    If this was a lithium system, you might get away with 1/2 the battery AH capacity--But Li Ion batteries have their own special needs. They are close to the "perfect battery" (no maintenance, long cycle life, high charge/discharge current, very efficient, no memory, can store at partial state of charge). The downsides.... They can be expensive, don't like to cycle below 40F, and depending on your desires, should probably have a BMS (battery management system) as part of the battery bank--To keep cells in the proper operating voltage range (and prevent over/under voltage causing a short life).

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DocWattDocWatt Registered Users Posts: 7 ✭✭
    edited December 2021 #11
    Ok, i've gotten to read the rest and here's what I have:
    Cycles per day (anticipated): 10 max...obviously that may be up or down some days, but i'm trying to average high to cover bases.  (I can't see needing more then 10 full cycles in a day, but it may happen a few times a year...not worth planning on that.)  I'm shocked to see 44 is the expected...way beyond what i'd need.
    Yes, one arm/one gate.  I agree the numbers seemed high, but those numbers were from the company, so I went with it.  You explained things beyond well and while I didn't understand all of it (and had to look-up some of the abbreviations...newbie...) I trust what you sent.  It does make me wonder though as I've spoken to multiple reps from the GC company and they each said if you're going solar only upgrade the panel from 10W to 30W and get a deep cycle battery.  They never said to get a 100AH or anything, so perhaps they just meant get a 14 or slightly more deep cycle as compared to their two 7 Ah batteries, which are lead acid.
    My original concern was what battery type to get, and it's looking like AGM is a good place to aim.  Does it still have issues charging in the cold? (As LiIon would?) 
    From your last post I also seeing that having to much battery is a bad thing.  i certainly hadn't thought about that enough, but it makes sense...not letting it get "enough exercise" in a way.  I guess this negates the lithium Ion options I suggested as these are only avaliable in 100 AH as the smallest, but they do have BMS and a self-heating system that work in sync to maintain the temp so it can operate and charge to around 5 deg. F, which is a simply solution for the temp issue.  As I asked above, do i avoid this with AGM or do I need to still find a way to warm them when it's below freezing?
  • BB.BB. Super Moderators, Administrators Posts: 32,612 admin
    For number of cycles--I was, more or less, matching "worst case" gate usage to a rough sizing of battery bank AH and solar panel wattage.

    For things that cycle for short periods of time (gate taking 5-15 seconds to open OR close) at a few amps... That is actually not a lot of energy (relatively speaking). However, the 0.020 Amps (20 milliamps) for 24 hours per day becomes significant... Example, say 10 seconds to open and close, for a full cycle, 10x a day * 4 amps. And 0.020 amps * 24 hours per day:

    Note... We can do calculations in Amps and Hours, or Watts and Hours... Typically we change everything to Watts because it is easier when you are working with loads that may be both 12 volts and 120 Volts (1 amp * 120 Volts = 120 Watts; 10 amps * 12 volts = 120 Watts). Both methods give about the same answer. Watts is "less confusing" because it is a "complete" unit--Watts=rate of power usage. Amps, if you are working all at one voltage works--But when working out power usage, need both Amps and Volts to do the calculations.
    • 10 cycles per day * 10 seconds per cycle * 1/3,600 seconds per hour = 0.028 hours per day usage (1.7 minutes total per day)
    • 0.028 hours per day * 4 amps = 0.112 AH per day for 10 cycles
    • 0.020 Amps (receiver) * 24 hours per day = 0.48 AH per day just for the receiver energy usage
    • Total Average usage = 0.112 AH + 0.48 AH = 0.592 AH per day system usage
    So, in the 10 cycles per day @ 10 seconds per full cycle--The receiver uses 4x more power per day than the gate actuator itself.

    A 10 watt solar panel on a 3 hour per day sun will supply roughly:
    • 10 Watts Pmp (Pmax rated power) * 1/18 volts Vmp (voltage max power) = 0.56 Amps Imp (current max power)
    • 0.56 Amps * 3 hours of sun per day (December) = 1.68 Amp*Hours per day
    • 1.68 AH from panel in December / 0.592 AH per day = 2.8x more "energy per day" from solar panel vs daily average usage
    A small AGM or similar battery of:
    • 0.56 Amp solar panel * 1/0.05 rate of charge = 11 Amp*Hour suggested maximum AGM battery capacity with 10 Watt panel
    • A 30 Watt panel @ 5% rate of charge would be 3x larger or ~33 AH suggested maximum AGM battery capacity (30 Watt panel)
    • A 11 Amp*Hour AGM battery * 0.50 max planned discharge * 1/0.592 AH per day = 9.3 days of "no sun" cycling to 50% discharge
    Having "accurate" current draw and cycle time is important here, as well as expected daily usage and clear access to sun (no trees, bushes, etc. partially shading of panel, etc.).

    And for solar powered systems--Having a 2x larger solar array than "calculated" from standard tables--A very good practice to account for bad weather, less than ideal location (a bit of shading, dirty panels, etc.) where you "need' the thing to function daily.

    Oversizing a system seems like there is no downside... But everything has its drawbacks. AGM/Lead Acid batteries don't like "sitting" at under ~75% State of Charge--They start to sulfate and "go bad" (in a few months or a year--Depending on how much discharge, how hot, etc.). Also, achieving a minimum rate of charge of 5% should nominally be beneficial for a lead acid battery (especially flooded cell--Helps mix the electrolyte). Larger array and larger battery bank, more cost up front, and more costs down the road for maintenance (battery wears out, panel gets broken). And if you have theft issues (remote gate, nobody nearby), having a $1,000 Li Ion battery and solar panel+controllers--A tempting target).

    Lead Acid batteries can freeze (if discharged and cold weather--A 100% dead battery will freeze at 32F). And you should avoid trying to charge a "frozen" lead acid battery. But 50% state of charge, freezing is around -15F for lead acid/AGM.

    Flooded Cell Lead Acid batteries, if they freeze, it will typically crack the case and ruin the battery. AGM batteries can freeze and will not usually be damaged.

    As always, get the battery manual and follow their recommendations... Trojan has a nice manual: 

    Li Ion batteries do not have a minimum rate of charge, can site at any "reasonable" state of charge for months/years (better than Lead Acid). And a small Li Ion battery an output much more current than Lead Acid (lead acid C/8 nominal discharge, for Li Ion C/1 or even faster discharge is fine. C capacity / hours to discharge). C/8 is 8 hour discharge rate... C/1 is one hour discharge rate.

    AGM is a form of Sealed Lead Acid battery--They have good discharge and charge profiles. And work really well at say 77F to -50F or lower (AGM batteries the closer to 100% State of Charge, the lower their freezing temperature) temperatures just fine (cold batteries have less "apparent" capacity when cold, but "recover" when warmed up again).

    Li Ion batteries cannot (in general) be cycled below ~40F. And ideally have a BMS to balance/protect cells. And as you have seen, a Li Ion Battery "system" can even have a strip heater to keep warm. Li Ion is great for 50F to ~115F (Li Ion batteries being more efficient will not "self heat" in hot weather--Another plus).

    I am not recommending batteries here--Just some you can check out and figure out what works best for you: (20 AH @ 12 volt Li Ion with BMS) (10 AH @ 12 volt Li Ion with BMS) (15 AH @ 12 volt AGM) (15 AH @ 12 volt AGM)

    Another suggestion is to get an AC+DC Current Clamp DMM if you are going to do a lot of electrical work in both AC and DC power systems... There are some pretty inexpensive clamp meters these days: ($50 "good enough" for our needs) ($130 "mid priced" meter)

    Note there are both AC+DC Clamp meters, and AC only Clamp meters... AC only meters are great, but don't work on DC power systems and cables (and AC clamp meter may be AC+DC rated for measuring voltage--So a bit of confusion there).

    A clamp meter is easy to use (just clamp on one wire) and measure the current flow. Meter is handy for sizing system capacity (wiring, battery bank) and debugging. Also great for understanding how a system works.

    Again, the links above are just suggested search starting points. I am not in the business, so I have no information as to the ideal price/performance brand battery for your needs (or vendor quality--The Solar-Electric website is our host here for the forum).

    If this is your "First time", I generally suggest that you start "inexpensive" and see how everything works for a year... If you have issues (shaded array, controller takes more current than specs, your system gets flooded in a drenching rainstorm, a thief walks off with a $30 battery vs a $300 battery)--You would not have spent too much money for that "experience".

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • BB.BB. Super Moderators, Administrators Posts: 32,612 admin
    edited December 2021 #13
    By the way, please feel free to ask your "basic" questions.

    We all started from zero--And had family/friends/teachers to instruct us on all this stuff (plus quite a bit from the school of hard knocks).

    I will will never tell you to "Google" something.

    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • DocWattDocWatt Registered Users Posts: 7 ✭✭
    Thanks again Bill.  I have had a few short term things take my focus, but will return to follow-up on this.  I apologize for the delay in getting back and again I sincerely appreciate your time, help, and patience with this.
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