Alarm Battery Charging

[oafpatroll]

Hot Tools have a nice 0-5A power supply for R1150. The one on the right.




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Thanks. Had no idea a bench supply could be had for so little money.

[atunguyd]

@atunguyd, do you run your bench supply and the boards charger simultaneously?

Yes.

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[oafpatroll]

Yes.

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Struggling to get my head around how the two would interact.

[Davidc]

Struggling to get my head around how the two would interact.

The alarm panel probably sees the power supply as a battery, for that reason the current should be limited.


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[DirkB]

It works, I also have a smart charger connected to my 18AH battery. Have been doing it for about 3 months now on my Paradox alarm system with zero issues. My battery is never off nor does it cut out.

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[janfred]

Struggling to get my head around how the two would interact.

As he said,"It will also not impact the alarm system as it only sees a 13.8v attached to it (ie fully charged batteries)."

The bench supply takes the place of the battery.

This should work well provided that the voltage required to limit the current to 1.4A is not less than 13.8V.

[atunguyd]

This should work well provided that the voltage required to limit the current to 1.4A is not less than 13.8V.

Nope it will be fine. If 12v is needed to limit to 1.4A then the alarm panel sees a 12v "battery" and also applies whatever voltage it needs to charges the battery at its 700mA. The battery (two 7aH in parallel) will not vary an eyelid at being charged at 2.1A.
That's the reason why I needed a bench power supply which is effectively a voltage limiting source in series with a current limiting source.

From my experimentation the bench supply seems to be protected from being a current drain, so the panel and battery never see a load of coming from it. I cannot say that this is the case with other bench supplies. Mine is an old analogue linear one from the old days. I would need to think about how a switch mode one would work in this configuration.


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[vrystaatgypsey]

Hi

I replaced a gel battery in an alarm panel with a lifepo4 battery a while back, yesterday my mate mentioned the the siren is not working.
After some fault finding, it turned out that the panel was no longer charging the battery and thus the siren did not have power to work.
Measured voltage on battery alone, 1.4v, phoned my supplier and asked if the battery was not supposed to cut out at approx 10v due to
bms? He said it should have.
Anyone ever experience that before with a securiprod lifepo4 battery?

Cheers
Sean

[Zuku]

Can the standard panel charger charge lithium? I thought it couldn't.

Replaced my PSU for perimeter beams 3 months ago. After load shedding does not charge the battery. Then I realized the new PSU charge but battery only last 30 min. So i replace the lead battery for a gel battery. The dealer want to sell a Lithium charger and battery. battery.

In the PSU that is 3 months old there is a big orange sticker :WARNING This unit is NOT suitable for Lithium battery charging"

[oafpatroll]

Nope it will be fine. If 12v is needed to limit to 1.4A then the alarm panel sees a 12v "battery" and also applies whatever voltage it needs to charges the battery at its 700mA. The battery (two 7aH in parallel) will not vary an eyelid at being charged at 2.1A.

I am just beyond the level of being competent to wire up a plug so please bear with the lower grade questions. Are you saying that the input from the bench supply is interpreted by the alarm system board as the state of charge of the battery and it therefore dials back it's own supply accordingly? if not that are you saying that the two combined are still within the acceptable parameters of the battery?