Beesource Beekeeping Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
1,005 Posts
Discussion Starter · #1 ·
All,
I have to set up 4 bear fences that need to be powered by 12V batteries. To charge the batteries, I purchased several 50W solar panels and each has a voltage controller. The controller has terminals for the solar panel, the battery and the load.
My question is around what the fence charger should be connected to. Should I connect the fence charger to the battery directly or should I plug it into the load terminals? Or does it make a difference?
Thanks!
 

·
Super Moderator
Joined
·
11,146 Posts
Most likely, the controller's separate battery / load connections are intended to protect the battery from the load damaging the battery. Such damage could occur from either drawing too high a current from the battery, or continuing to draw from the battery after the battery is already significantly discharged.

Your fence charger system isn't a high current device, so that problem won't occur. But if you plug the fence charger into the controller's load terminals, you are allowing the controller to decide when to "cut off" the fence charger. Also, if the controller fails, your fence charger also quits right then.

If you wire the fence charger directly to the battery, the fence charger will continue to operate until the battery is depleted. I would avoid using the controller "load" terminals in this application. It would be smart to periodically check the battery voltage with a voltmeter just to be comfortable the solar panel & controller are doing their jobs.

.
 

·
Registered
Joined
·
148 Posts
The fence charger should go on the "Load" terminals.

The charge controller will shut down the load circuit on low battery voltage (10.5 volts +/-), to prevent your load (fence charger) from continually draining your battery below that voltage...protecting your battery from damage.

From what I've seen, the order of connection to the charge controller is usually:
1. Connect storage battery first. The charge controller will sense the system voltage and decide which charging circuitry to use (12 volt or 24 volt)
2. Then connect the solar panel

The order of disconnection is opposite:
1. Disconnect the solar panel first.
2 Then disconnect the storage battery (otherwise it can damage the controller)

I put a kill switch on my solar panel's (+) input wire to the charge controller, to make an easy way to disconnect the solar panel for whenever I need to remove the battery from the system (for swapping out, removal for fast charging on a typical battery charger, etc.)
 

·
Registered
Joined
·
6,558 Posts
I feel that since this is about beekeeping, I should offer the complete opposite opinion. But I won't. :)
Yes. I think I would rather have an overdrawn battery than a bear ravaged yard. I would give preference to protecting the bees rather than the battery.
 

·
Super Moderator
Joined
·
11,146 Posts
I got your joke; :D and see that you are a keen observer of Beesource threads. :p

[hr] [/hr]

Yes, bypassing the "load" terminals does not allow the controller to protect the battery. But, in the big picture, the battery is not the most important issue here. Keeping the "bear fence" running as long as possible is the key to protecting the really significant investment - the bees.
 

·
Registered
Joined
·
148 Posts
I got your joke; :D and see that you are a keen observer of Beesource threads. :p

[hr] [/hr]

Yes, bypassing the "load" terminals does not allow the controller to protect the battery. But, in the big picture, the battery is not the most important issue here. Keeping the "bear fence" running as long as possible is the key to protecting the really significant investment - the bees.
When I asked the manufacturer of my fence charger what would happen if the input voltage got below 10.5 volts they replied "It will still send pulses out, but they will be much slower (much longer time between pulses) and with much reduced voltage (or joules), to the point of not really working well on animals like bears. We recommend a charge controller to protect the cost of replacing a battery damaged from being drawn down too far."

I don't know (& they couldn't answer) what the relationship of input voltage to output voltage or joules was. I assumed that if I get 10,000 volts & 1 joule on 12 volts that I would get 5,000 volts and 0.5 joule if the battery was run down to 6 volts, but I'm not electrically minded in that way. I did read elsewhere that when a 12 volt battery gets below 8 volts, it won't take a recharge ever again.

So my takeaway from that conversation was I could run the battery down low enough so that the fence charger isn't going to deter a bear with its weak pulses, I still lose the bees, and I would have to buy another 12 volt battery on top of it all.

Like they use to say, "Six of one, half a dozen of the other..."
 

·
Registered
Joined
·
5,728 Posts
I did read elsewhere that when a 12 volt battery gets below 8 volts, it won't take a recharge ever again.
My smart charger won't charge them, but my trinkle(sp) charger put on low slow charge after a while will get it back up to where the smart charger can. they don't take too many of these however .
 

·
Registered
Joined
·
223 Posts
The fence charger should go DIRECTLY on the BATTERY TERMINALS. The solar charge controller will prevent over charging the battery by diverting power to the LOAD (typically a heater element) to not waste power, but if nothing is there it just stops charging when the battery is full.
 

·
Registered
Joined
·
6,558 Posts
If your battery is sized to run the fencer for a week without charge (which it had better be) then you would have to check the solar charger at least once a week regardless of where you tap the power. If you have a failure warning system you trust to notify you that the fencer is off line then you might think it worth while to protect the battery from harmful discharge level.

My risk/benefit analysis was not much of a challenge; put the fencer directly on the battery. Bears are a certainty here and a dead battery only a remote possibility. Even a nuc here is worth the price of three or four batteries!

I borrow someone elses signature line: Never ask a barber if you need a haircut!
 

·
Registered
Joined
·
148 Posts
For what it's worth, I've had my two systems setup since day one without ever using the load terminals. The batteries are connected to their controllers, the fence energizers are connected to their batteries...as Rader and Crofter previously said.
 

·
Registered
Joined
·
6,558 Posts
Some of the solar powered fencers have a ridiculously under capacity collector panel and unless you are in an area with few cloudy periods they will run their dinky batteries in a constant undercharge condition. The result is sulphation; the biggest enemy of lead acid batteries. They might serve where they can be checked often but not suited for an outyard.My son has half a dozen of them but uses stand alone larger panels and an automotive battery from Costco or Walmart.
 
1 - 14 of 14 Posts
Top