Alarm system charge currents and backup batteries

[Isetech]

Living in SA we have this load shedding issue which has been around for many many years, probably going to be around for many more years.

Security system backup becomes a challenge because they are designed to trickle charge the battery, to prevent over charging resulting in excessive heat, which will drastically reduce the battery life span. One of the solutions to keep the system running during load shedding or other outages (very common in some areas) is to fit a separate power supply with an 18 amp/hr battery. You move all your peripheral devices over to the bigger battery, which also has a higher charge current.

This solution is great for 2 days of load shedding, however if the the load shedding continues for 3 days or more, then you are faced with a problem. The charger will not be able to keep the battery topped up, eventually the battery will drop below 120.5 VDC and drop out. You will have to contact your armed response company and they will send out a technician to replace the battery at a cost of around R800 and add to the thousands of 7 amp/hr batteries being dumped.

I get a lot of calls requesting a router backup solution, if you have an 18 amp/hr power supply, generally the routers are 12 VDC, just connect it directly to the same 18 amp/hr power supply your alarm is using.

I have been trying to find a solution to this 7 amp/hr problem for a while now. I have considered using a lithium battery replacement, however I cannot get credible data out of the lithium battery supplier which will support their theory that it is a plug and paly solution, considering the charge characteristics.

I have spoken to one of the local alarm manufactures, but they have no intention of modifying or upgrading their systems to charge a lithium battery.

Then we look at another solution, an inverter with a lithium battery. A cheap plug and play 3 kva lithium setup is going to set you back around R30k, very few people would even consider outlaying that kind of money just for the security system.

There is also the option of adding a relay, if the power drops the relay closes and the system is fed from the 18amp/hr battery. Then you could do away with the 7 amp/hr battery.


Another option would be to fit a smart charger (not sure if this work work) to the alarm system and connect it directly to the lithium battery, then you have charge current available and the backup as when required, you could also double up the battery or use a bigger lithium battery. I dont know that you could have the power supply/charger power from the alarm and the smart charger connected at the same point.

The other option would be to use a solar panel and a charge controller also connected directly to the battery wit the alarm power/charger circuit.


I would like to hear your thought or suggestions.

[Justloadit]

Check this review on the Blue Nova drop in replacement

[Justloadit]

From another website

Not sure if this is the correct solution for a D5 Centurion gate drive, as the information is not readily available, the D5 charge 14.1V, will it harm the battery, or reduce the expected lifespan?. or would the BMS take care of that? who knows?

''www. livecopper.co.za"" replied:

The BN13V-8-104Wh battery will work in this application. The charge voltage of 14.1V is adequate to recharge the battery to 100%.
The battery will not be harmed, nor will the battery’s lifespan be reduced beyond what is expected from normal operation in this application.

The battery has not been tested as to whether the charger will “wake up” the battery if it has been over-discharged to the point of auto-disconnection.

We don't believe this will be a problem. This is normally only an issue in certain UPS devices that have to detect a battery voltage before commencing charging.

[Isetech]

Check this review on the Blue Nova drop in replacement

I have contacted Blue Nova to discuss this battery ( I wanted to purchase about 50 units for resale) , however at the time they could not produce any credible recorded data. The response was "we have one at home". When you tell a customer they have to spend 5 times the price of a lead acid replacement, they expect a little more reliable information.

My concern is the 7.2 amp charge current (max), most alarm systems are only 0.5 amps.

[Isetech]

From another website

The only way to find out is to run tests, maybe one day I will order one of these batteries and test them, but for now I can replace batteries for the next 10 years and not justify spending R1000 on a small battery. I am considering looking into a 100 amp/hr lithium battery replacement (10 times the capacity, not 10 times the price).

[GCE]

Our solution has been to supply a 600 to 1000 watt inverter ( decent quality , like Averge ) , 2 x 100amphr gel batteries ( now changed to lithium 200amphr) and install a small sub DB with alarm , router, tv, dstv and gate motor fed from the Sub DB ( dedicated sockets ) and maybe passage lights if LED or change to LED

Comes in at around 15 to 20 K - Ensure that the load is around or below 300watts.
My pitch - " Keeps the toothache out of load shedding"

Is the only solution that I have found that keeps things simple and security systems on without having to change batteries every couple months .

After that it jumps to 60K ( convenient factor only ) , next jump 160K ( 60% of elec bill sorted) and almost final jump at 300K ( 90% of elec bill sorted)

At " home" the place that I go to, to sleep , I have a inverter and 2 x 100 amphr gel batteries feeding the alarm system only because the beep at start and finish of loadshedding pisses me off

[Isetech]

Our solution has been to supply a 600 to 1000 watt inverter ( decent quality , like Averge ) , 2 x 100amphr gel batteries ( now changed to lithium 200amphr) and install a small sub DB with alarm , router, tv, dstv and gate motor fed from the Sub DB ( dedicated sockets ) and maybe passage lights if LED or change to LED

Comes in at around 15 to 20 K - Ensure that the load is around or below 300watts.
My pitch - " Keeps the toothache out of load shedding"


Is the only solution that I have found that keeps things simple and security systems on without having to change batteries every couple months .

After that it jumps to 60K ( convenient factor only ) , next jump 160K ( 60% of elec bill sorted) and almost final jump at 300K ( 90% of elec bill sorted)

At " home" the place that I go to, to sleep , I have a inverter and 2 x 100 amphr gel batteries feeding the alarm system only because the beep at start and finish of loadshedding pisses me off

I have a 600 watt inverter with 2 x 100 amp/hr lead acid batteries (to be upgraded once they fail). It keeps all the security system stuff, router and TV stuff on for around 6 hours. The gate works for 2-3 days on its own battery. 13 days without electricity and water taught me a few new tricks . We had hot bucket showers every day. I plugged the magneto lights (they keep going for around 10 hours ) into the inverter when they got low, positioned around the house correctly only 3 of them to light up the whole house. I have found a replacement battery for the magneto, no need to replace the whole light every 2 years.

What type of charger do you use for the 200 amp battery? Iahve thought about a solar panel with a charger controller. I don't believe the small inverter (mecer for example) have a lithium charge function ? I haven't looked at the newer model spec sheet.

[Isetech]

We use the magneto LED for on a daily basis for site work, best LED light I have found, I tired many LED light for site work, 3 -4 hours and they are dead. I need to get around to making a lithium replacement for the magneto, that would be a hands down win, like slide bread

[Isetech]

My concern is the bulk and float voltage, most alarms and gates only offer 13.8 volts for charging. I am not too clued up on this, so someone like justloadit would be able to advise, the impact of not offering 14.4 VDC for charging. After a few days of stage 4 load shedding it could prove to be an issue.

If I understand how lithium works, it would take a couple more days than a lead acid to drop below 10,5 VDC and drop out the system.

Taken from the blue nova spec sheet

Bulk Voltage 14.4 VDC
Float Voltage 13.8 VDC
Discharge Voltage (min.) 11.6 V
Charge Current 7.2 A continuous

[GCE]

I have a 600 watt inverter with 2 x 100 amp/hr lead acid batteries (to be upgraded once they fail). It keeps all the security system stuff, router and TV stuff on for around 6 hours. The gate works for 2-3 days on its own battery. 13 days without electricity and water taught me a few new tricks . We had hot bucket showers every day. I plugged the magneto lights (they keep going for around 10 hours ) into the inverter when they got low, positioned around the house correctly only 3 of them to light up the whole house. I have found a replacement battery for the magneto, no need to replace the whole light every 2 years.

What type of charger do you use for the 200 amp battery? Iahve thought about a solar panel with a charger controller. I don't believe the small inverter (mecer for example) have a lithium charge function ? I haven't looked at the newer model spec sheet.

We use the Averge inverter -

[Justloadit]

My concern is the 7.2 amp charge current (max), most alarm systems are only 0.5 amps.

This simply means that you must not exceed 7Amps on your charger, the fact that the current charger is only 0.5Amps means that a flat battery will take 14 hours to charge fully.
If your charger was say 3.5Amps, then it would charge the battery in 2 hours.

Lithium is not like lead acid, where a slow charge over many hours to charge is the norm.

You can charge a Lithium battery at 50% capacity without any issue besides watching that the temperature remains below 40°C

[Justloadit]

My concern is the bulk and float voltage, most alarms and gates only offer 13.8 volts for charging. I am not too clued up on this, so someone like justloadit would be able to advise, the impact of not offering 14.4 VDC for charging. After a few days of stage 4 load shedding it could prove to be an issue.

If I understand how lithium works, it would take a couple more days than a lead acid to drop below 10,5 VDC and drop out the system.

Taken from the blue nova spec sheet

Bulk Voltage 14.4 VDC
Float Voltage 13.8 VDC
Discharge Voltage (min.) 11.6 V
Charge Current 7.2 A continuous

This specification is typical for a Lead Acid battery.
They have created a Lithium pack which will work to these specifications.

Typical Lead acid batteries, once the charger is removed, the voltage drops quite a bit, not so with Lithium.
Lead acid has a non linear discharge curve. where as Lithium is a linear discharge curve with a smaller voltage differential from fully charges to discharged.

[Justloadit]

The only way to find out is to run tests, maybe one day I will order one of these batteries and test them, but for now I can replace batteries for the next 10 years and not justify spending R1000 on a small battery. I am considering looking into a 100 amp/hr lithium battery replacement (10 times the capacity, not 10 times the price).

Yep at say R800 a year translates to R8K in the 10 years, versus once of R800 for Lithium for the same period.
Your choice

[Isetech]

Can you connect a smart charger directly to an alarm battery with the alarm charger at the same time?

[Justloadit]

Can you connect a smart charger directly to an alarm battery with the alarm charger at the same time?

It depends on what the alarm charger does. If I remember correctly they have a simple voltage regulator which runs at 13.8V,
The smart chargers like to disconnect the charger once the battery reaches 14.4V, and then waits for the voltage to drop to 12.8V to then go into trickle charge mode. With the 13.8V from the alrm charger, the smart charger will remain disconnected, and would require you to disconnect and reconnect for it to reset the cycle.