Hi

I have a 5 unit M9-plus mesh setup in my house and i am still struggling to find wi-fi signal in parts of the house. It is a 4500sq ft 2 story house. 2 units are on ground floor (including main router unit)  and 3 units on the upper floor. I am struggling to get a decent wi-fi signal to my Ring Outdoor bell (the closest unit to it is 15 ft away which is one of the inside Grd floor unit). RSSI to Ring Bell is -80. One of the upper level units is also about 15 ft from the Ring bell (vertically).

Question:

1. How do I improve the signal strgenth to my Ring bell. Currently my outdoor bell battery drains too fast because of the weak wi-fi. 2 weeks battery on full charge as opposed to 6 months they promise it should last?

2. All M9Plus units are placed hortizontally on a table. Is there a value in raising their height through a wallmount or a celing mount?. ? Will this improve/deteriorate wifi signal. 

3. Is there a weather proof outdoor unit Tplink makes which i can add to my existing mesh network to supply to Ring?

Appreciate some views and advice.

regards