Expandable Zigbee Repeater Solution (With Temperature, Humidity, Pressure and Light sensors)

Hi Everyone,

The build for battery backup is completed. I am testing the unit at this moment. It will support one cell lithium polymer and lithium ion battery only. These typically translate to 3.7v lipo battery that you find in toys. It supports unprotected battery. My recommendation is to use unprotected battery. The module has under and over voltage protection. It should also work with protected battery.

Here they are.

The first variant is just like the old module with battery attachment.

The second variant use thinner pcb but extend all the way to cover the antenna. I would like to try if we can make lighter board. The board is slightly larger to help with the structure to compensate for the thin board.

The last variant is much bigger board to test using 18650 cell. I probably will not make this variant anymore. The cost of battery holder is expensive. I also do not know how to ship them yet. I want to give you guys a try so that I can get some feedback. If this variant is really useful, I would have to think about how to source the battery holder better.

Battery selections is interesting. I design it as a backup power. It is not an alternate power source. In my mind the backup power is only needed temporarily. Therefore, a small battery is making sense. As an example, the battery on the second picture can last about 1 to 2 hours. This should be enough to cover power outage in home that has generator backup. The battery will cover that short time before the generator kick in in the event the main power goes out. This is my personal choice. The battery on the first image can last about 4 to 5 hours. The module that can fit 18650 battery cell can last much longer. These cells come with variety of capacity. It is hard to say how long it will last. I use Panasonic 18650 NCR18650B to test. This should give you about 18 hours of backup time.

The module will use approximately 150 milliamps. You can approximate how long it will last with the battery you use.

I typically build one or two modules and test them quite a bit. Then, I build the rest of the modules(set of 10). I smoke test them before I send them out. Now, it is hard to smoke test the battery functionality. It will take a very long time to charge and discharge the battery and test each one before I ship them out. Therefore, I will not smoke test the battery functionality. I will smoke test the other functionality before shipping.

At this time, all modules is fitted with all sensors. If you are interested, pm me. I do request $28 donation for each module to recover the hardware cost. If you interested on variant that hold 18650, I may need additional help to cover the shipping cost. I will do some research and get back to to you next week if you interested on this variant (the third picture).

I expect to ship them out this week especially the smaller module(picture 1 and picture 2).