Include external battery for emergency power outages

[mattylad]

Alarm did you miss this bit?

Nope.

Just bells - and friendly/helpful neighbours

Is it monitored?

Its a house alarm, the system is not monitored.
A UPS does not need constant monitoring for this.
For a fire alarm yes, but not for a house alarm. Just regular testing.

If the mains goes off then you get the life of the battery providing the power to the whole system, when that dies then you use the battery.

Heck, adding more batteries of the same type with relays to switch in good ones while switching out bad ones and a little low voltage detection circuit (and isolation diodes) would help keep the whole thing going for a lot longer.

Just having spare batteries trickle charged and manually swapping them over will also work.

Alarm, your'e making out that simple additions of some additional batteries a trickle charger and some isolation are going to cost circa £300. NO blooming chance! Not unless your providing them.
This is a DIY site and this can be DIY'd for less than £50 easily.

 

[redpis]

The OP could always go with a 17Ah battery charged from a suitable power supply unit and feed the DC output directly in to where the transformer secondary is connected on the board (noteing all the safety aspects when working with electrcity, ensure mains is isolated etc).

I have done this on systems overseas and it works just fine, also it makes no differance which way round the polarity is when you connect the AC in of the board.

 

[Alarm]

Matty I have not said what would be "charged" apart from the battery.
A Alarm system NEEDS to monitor ALL aspects of its items and controls.

Redpee, overseas counts for nothing.

Your both again ignoring aspects here that count.

A system that should work and not endanger lives.

A system that CONSTANTLY monitors these issues.


Not a 50 quid make shift possible life threatening bodge.

Getting bored now, as a system should protect. NOT be a possible DANGER.

Once a few more here understand this, the better.

 

[SimonH2]

I am curious about the design of this apparently poor quality charger used in these panels. Any charger intended to handle LA batteries from discharched, and cope with faulty batteries (note the comment about "what is a cell goes short circuit) musthave a constant current step to it's charging regime (aka a current limit to limit the charge current to what is safe for the circuit).

Thus, within limits, sticking a 17AH battery in place of (or in addition to) a 7Ah should not be capable of damaging the charger. The charger will simply operate in CC mode for longer during the bulk charge phase. If the charger can't handle that then it's not fit for purpose<period>.

Also, I still fail to see why adding an external battery with blocking diode isn't safe ? You'd never get the situation where you'd connect a fully charged battery in parallel with a fully discharged one - unless you had left the external disconnected and waited until the internal was completely flat before connecting it. Even then, any cross charging would actually be of very limited current and duration - once a current flows, it doesn't take long for the effects of internal impedance and changes in cell voltages to level things out.Normally you'd just leave it connected, and when the power goes off, the panel will draw from both batteries and discharge them together.

And for the case where a battery has a cell go short circuit ... Well apparently (according to comments above) the charger will conflagrate and burn down the whole village (OK, I exaggerate a tad ). But it's common to parallel batteries in all sorts of situations and they don't go up in smoke because of it. In any case, I think man invented something that will limit current in a circuit ... oh yes, I think he called it "a fuse". So a fuse in the external battery connection (would be good practice anyway) rated a little more than the current draw of the system would deal with that.
My experience is that small SLA batteries tend to fail open-circuit as cell dry out.

 

[yaleguy3]

..and to think when pushed in a previous post about making an alarm system last 24 hrs without power 'Alarm' had said it was easy to do - and then look at this thread.. lol You could always install a Yale 6200 as a backup alarm to the main system - they work for at least 18 MONTHS not a few hrs without mains power and it would be a cheap option.

 

[bernardgreen]

Well apparently (according to comments above) the charger will conflagrate and burn down the whole village (OK, I exaggerate a tad )

The explosive power of the oxygen + hydrogen mixture from an out gassing battery should never be trivialised. Sadly I no longer have the picture of the 5 foot tall 19 inch IP66 cabinet in which a relatively small "sealed" battery had gassed out a dead cell. A spark from a contactor triggered the explosion. It did " only blow the doors off " so no serious damage. It was of course stupid to have the battery in a sealed cabinet but some people do not look at the "what if" situations that might occur.

 

[SimonH2]

... It did " only blow the doors off " so no serious damage. It was of course stupid to have the battery in a sealed cabinet but some people do not look at the "what if" situations that might occur.

Indeed, "sealed" is a misnomer - which is why they now call them Valve Regulated Lead Acid (VRLA) which is a better description since they have valves to relieve any excess pressure. Of course, once they do vent, then that's your very limited supply of water disappearing.

I've been experimenting since I found myself with a large supply of dead batteries of various sizes at work - from about 6V4Ah to 12V44Ah. 1) Most are actually quite easy to get the lids off. 2) If they aren't too far gone, some can be brought back to life with a small quantity of demin water. 3) If you add too much water ... well you find they aren't designed to be wet and don't really have enough internal space to hold the excess when you start making them gas
I'm rather hoping I can get 2 or 3 of the 44AH ones back to life (I've 20 to go at !), they'd do nicely in the car.

EDIT:
And of course, if a cell goes short circuit, then it's a very good charger that's not going to keep trying to charge it, and gas the other cells dry.

 

[Alarm]

and to think when pushed in a previous post about making an alarm system last 24 hrs without power 'Alarm' had said it was easy to do - and then look at this thread..

It is when done correctly.
As you have no idea, why post?
Saying to put in a second system.....................ROFL your still showing how silly you are.

 

[mattylad]

Your both again ignoring aspects here that count.

A system that should work and not endanger lives.

Its a house alarm, not a blooming life preserver.

No one said it is under contract?

replacing the battery with a charged one during a power cut will not cause any problems that cannot be resolved by entering a code and resetting the alarm.


Your making a mountain out of a molehill.
Besides, the OP has already resolved the problem.

 

[Alarm]

Its a house alarm, not a blooming life preserver.

No one said it is under contract?

replacing the battery with a charged one during a power cut will not cause any problems that cannot be resolved by entering a code and resetting the alarm.


Your making a mountain out of a molehill.
Besides, the OP has already resolved the problem.

Errr, a alarm system is to protect property and life.
It is under contract as mentioned before, hence the maintaining company being asked for the upgrade.
The mountain is because the works done is inherently dangerous.
The issue has been resolved on the cheap and not correctly.

Kindly stick to what you know, not guessing and making silly comments.

 

[SimonH2]

Errr, a alarm system is to protect property and life.

Err, there's next to no element of "protecting life" - it's an intruder alarm, not a fire alarm.

The mountain is because the works done is inherently dangerous.

On that basis, any property without an intruder alarm is inherently dangerous. OH MY GOD, I won't be able to sleep tonight now I know that

I think you need to get a sense of proportion.

 

[Alarm]

PA button (HUD) maybe?

But your the one taking this further now onto the realms of silliness so do carry on by yourself.

 

[SimonH2]

PA button (HUD) maybe?

Only a few PIRs were mentioned.

But your the one taking this further now onto the realms of silliness so do carry on by yourself.

Well some people are simply trying to keep things in proportion.

The vast majority of domestic residences have no alarm at all, yet you are arguing this one is somehow majorly safety critical. Unless there is some other purpose we've not been told about, this is most likely a simply "persuade the thieving scum to go elsewhere" basic property protection alarm and your concerns seem somewhat OTT.

Now, if it were (say) a fire alarm in a home for vulnerable and/or infirm people then I'd agree with you - it becomes a matter of life and death. But AFAICT it isn't and it isn't.

I note that nothing has been said about the nature of the charger and the comments I made earlier about any fit-for-purpose charger having a current limited phase to it's charging regime.

 

[Alarm]

And we know not of what is all fitted.
It has been eloquently put about the risks of the cheap alternative.

Feel free to keep arguing, with yourself.

 

[SimonH2]

Feel free to keep arguing, with yourself.

Sorry to disappoint you, but I'm in complete agreement with myself - so no argument there