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Thursday, April 29th, 2021 8:58 PM

Original Simplisafe Siren

Hi all --

I've had Simplisafe (original) for about 7 years. Overall I've been very pleased with it. Can anyone tell me if they have ever tried using rechargeable NiMH AA batteries in their siren? Of all the devices, the siren seems to really chew through the alkaline batteries. Was wondering this: as long as I'm changing them so frequently, does anyone use rechargeables in the siren and get a decent amount of time out of them until next recharge? Thanks for your thoughts.

P.S. Am I just losing my eyesight or is there no SEARCH function on these forums?


1.3K Messages

3 years ago

No overtly obvious search. Allegedly there is somewhat of one on some well-hidden page, but I use Google Advanced Search if I really want/need to do some digging.

Far as rechargeables in siren, no, never tried. Doubt the standby time would be much longer, if any, but probably lower cost in the long run.

Community Admin


5.3K Messages

3 years ago

Hi bdmillan,

Technically yes, NiMH's should work just fine. From our experience, they won't last as long (on a single charge) as alkalines. But if you're okay with recharging them every few months, it'll be much more cost-effective.

Though the regular alkalines should really be lasting you about 8-12 months (same as a Keypad). If it's much shorter than that, there might be some heavy interference that's forcing the unit to work harder than it should to maintain the signal, which results in rapid battery drain. Of course, our Support team at 800-548-9508 can help with that, step by step!

- Johnny M.
SimpliSafe Home Security

7 Messages

2 years ago

External battery pack for siren:

Disassembly notes: The actual siren module is mounted behind the front cover and is connected to the main unit by two small wires. The pushbutton is connected in a similar manner but the button assembly will slide out of its slot in the front cover so it shouldn't be an issue. You could unplug the connector where the siren module wiring plugs into the main unit in order to separate the front cover from the remainder of the unit.

For the external pack, I used an older base station (BS2000) which has rechargeable AA batteries and a wall charger. I simply connected a 2-conductor cable to the battery terminals in the BS2000 base station and connected the other end of that cable to the battery terminals in the Gen 3 siren by soldering the cable wiring to the circuit boards in each unit.

The batteries in the siren are no longer needed because the rechargeable batteries in the BS2000 now power the siren. I also unplugged the wireless board in the BS2000 along with its speaker. (Large multi-wire connector and red/black 2-wire connector.)  In addition, I clipped the green wire that powers the blue LEDs. Now, the only apparent "activity" in the base station is a single red LED on its main board. (IF you unplug the remaining larger connector near the red/black connector, the battery charging function will not work - I tried that hoping the battery charging circuitry was in the BS2000 base. But, no charging with that connector unplugged.)

Some hole drilling (in plastic) and soldering was required. This conversion requires familiarity with electronics, wiring layout, etc. It is not all that difficult just a bit tedious.

One point worth noting: The rechargeable batteries in the BS2000 are rated at 1.2 volts each. Their charging voltage is under 1.5 volts. So, the voltage present at the siren's battery terminals will be 6 volts or less. (4 times 1.5 = 6.) Thus, the siren will not see more voltage than it normally does when using regular AA alkaline batteries.

This conversion may not be ideal if your siren is wall mounted. Mine are not so I can place the siren and BS2000 side by side without issue. Obviously, an outlet needs to be available to power the wall charger.

I am NOT suggesting that your perform this modification. I am simply describing the general concept and my experience in doing so. If you choose to do so, your result may vary from mine. I'm pretty sure that doing this will void the siren warranty. But, this is one useful way that I found to repurpose older base stations.

It might be possible to use a 4-cell battery holder and an appropriate charger for this conversion or to connect the charger to the siren and use rechargeable batteries inside the siren instead of the regular AAs.

SimpliSafe should build that option into these sirens - An either/or situation: Use rechargeable batteries with the charger or regular AAs without it.

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