Batteries in electric fence energisers

[Bobster.]

I have a Nemtek Wizord 4 energiser for my electric fence. 

This started playing up yesterday and the problem was traced to a dying battery. Swop the battery out and bingo! Everything working properly again.

The question is do I need this battery given that I am unlikely to suffer a loss of mains to the energiser? 

I recently had my garage and electric motor serviced. The guy says to me the battery is flat as the proverbial, but that's only a problem if you lose power and you have all these panels on your roof. We discussed. He said OK... fine... we run it without the battery. I don't know if he changed any jumpers in the control unit. He removed the battery completely, didn't leave the pap one in place.

But these batteries never seem to last. I have three that I know of in my security system. One of the energiser, one for a box that makes clicking noises when we press a panic button, and one that... well I don't know what that box does (it has an external power supply too).

Life would be simpler and cheaper if I can just remove all these batteries. They were once useful for keeping things going under load shedding, but now we have protection against load shedding so do I need these batteries?

Edited June 18, 2021 by Bobster
extra detail

[YellowTapemeasure]

1 hour ago, Bobster said:

I have a Nemtek Wizord 4 energiser for my electric fence. 

This started playing up yesterday and the problem was traced to a dying battery. Swop the battery out and bingo! Everything working properly again.

The question is do I need this battery given that I am unlikely to suffer a loss of mains to the energiser? 

I recently had my garage and electric motor serviced. The guy says to me the battery is flat as the proverbial, but that's only a problem if you lose power and you have all these panels on your roof. We discussed. He said OK... fine... we run it without the battery. I don't know if he changed any jumpers in the control unit. He removed the battery completely, didn't leave the pap one in place.

But these batteries never seem to last. I have three that I know of in my security system. One of the energiser, one for a box that makes clicking noises when we press a panic button, and one that... well I don't know what that box does (it has an external power supply too).

Life would be simpler and cheaper if I can just remove all these batteries. They were once useful for keeping things going under load shedding, but now we have protection against load shedding so do I need these batteries?

It depends.

You need to evaluate the impact / severity of the non-availability of the device / service due to the power outage, and then make a risk-based decision, based on your own risk appetite. It's also useful to do it based on a time-scale (for example, a 60 minute outage of your garage door motor may be a PITA, yet not severe risk, but after a one week outage it may start becoming an issue).

An electric fence secures your home and loved ones, so this may be more critical for you. Your risk appetite may be far less than the garage door motor, because threat to life and limb trumps a pulled muscle (from stretching to close the door manually). Being a security device, defense in depth also comes into play, hopefully it's not your only security device, you may have an alarm, and beams / passive detectors, and these may also benefit from being on a redundant power supply. After all, you may be able to guarantee far better electricity reliability than Eskom, but there is no way that you could guarantee 100%, even with significant investment.    

[Bobster.]

4 hours ago, YellowTapemeasure said:

It depends.

You need to evaluate the impact / severity of the non-availability of the device / service due to the power outage, and then make a risk-based decision, based on your own risk appetite. It's also useful to do it based on a time-scale (for example, a 60 minute outage of your garage door motor may be a PITA, yet not severe risk, but after a one week outage it may start becoming an issue).

An electric fence secures your home and loved ones, so this may be more critical for you. Your risk appetite may be far less than the garage door motor, because threat to life and limb trumps a pulled muscle (from stretching to close the door manually). Being a security device, defense in depth also comes into play, hopefully it's not your only security device, you may have an alarm, and beams / passive detectors, and these may also benefit from being on a redundant power supply. After all, you may be able to guarantee far better electricity reliability than Eskom, but there is no way that you could guarantee 100%, even with significant investment.    

Thank you for all of that, and you are right about weighing up the risks. But I need an answer to the technical question. Since you didn't say something like "it must have the battery or it will blow up" can I assume that the answer is "yes, they can run without the batteries"?

[YellowTapemeasure]

11 minutes ago, Bobster said:

Thank you for all of that, and you are right about weighing up the risks. But I need an answer to the technical question. Since you didn't say something like "it must have the battery or it will blow up" can I assume that the answer is "yes, they can run without the batteries"?

OK, so now I get your point. In the 80s we had 50cc motorcycles which could run without the battery if the leads were joined together, but the lights used to blow because the lack of internal resistance which pushed the amps up.

I guess that it's more a question then for Nemtek tech support. 

[Bobster.]

The Nemtek literarure says their energiser is battery powered, and a pap battery just caused me hassles, so really I have the answer there. 

The other boxes... Well it would help if I knew what they do. They are not branded so I can't Google, unless maybe I took the PC boards out and hope to not blow anything. 

[Bobster.]

I think I am starting to see some light here. The battery in my energiser works in pulses. It is not running flat out all the time. So the charger doesn't have to match the maximium output of the battery, it just has to do enough to keep the battery more or less charged over a period of time. So the fence probably couldn't run effectively on just the mains, because the charge circuitry is not designed to cope with the peak demand on the battery, it matches the average demand,

In which case that cell that @Vassenmentioned might be a good long term investment. It costs more, sure, but will last a lot longer and will be less likely to fail every 2 years or so just as I am sitting down to watch Strictly Come Dancing on something of similar importance.

[Rdelete]

On 2021/06/18 at 11:24 AM, Bobster said:

I have a Nemtek Wizord 4 energiser for my electric fence. 

This started playing up yesterday and the problem was traced to a dying battery. Swop the battery out and bingo! Everything working properly again.

The question is do I need this battery given that I am unlikely to suffer a loss of mains to the energiser? 

I recently had my garage and electric motor serviced. The guy says to me the battery is flat as the proverbial, but that's only a problem if you lose power and you have all these panels on your roof. We discussed. He said OK... fine... we run it without the battery. I don't know if he changed any jumpers in the control unit. He removed the battery completely, didn't leave the pap one in place.

But these batteries never seem to last. I have three that I know of in my security system. One of the energiser, one for a box that makes clicking noises when we press a panic button, and one that... well I don't know what that box does (it has an external power supply too).

Life would be simpler and cheaper if I can just remove all these batteries. They were once useful for keeping things going under load shedding, but now we have protection against load shedding so do I need these batteries?

I replaced all my 7AH with the 8AH from take a lot at around R550 a battery long before inverter purchase. Thats Electric fence (Exactly the same as yours), centurion swing gate motor and the alarm which was a big problem when on 4 hours load shedding the gate and alarm stop working. problem solved. Have not replaced a battery since. Your gate / garage doors dont work without a battery. Lucky the fence does with out battery but has to have AC all the time. I have not replaced any battery yet, definitely more than two years.

https://www.takealot.com/12v-8ah-battery-lead-acid-gel/PLID59533565

 

Edited June 22, 2021 by RyanG
battery a must , No dancing with no battery power >> Gate motors, Alarms, Garage doors