why no one should buy the $120 Renogy 100w solar kit (flash sale)

This terrible kit is on sale.  Yes, it’s substantially discounted from the normal price but it’s still terrible. Don’t buy it.

Let us consider the cluelessness here:

  1.  mono panels are a poor match for PWM/shunt controllers, due their higher voltage (and hence lower current at a given rated wattage).  The kit would make 6% more power if they sold it with the poly panels.   They’d make more money, the customer would get more power.  Win-win.

  2. the 30A Wanderer PWM is massively overspec for 100w of panel

  3. the Wanderer series is hard-configured for 120 minutes of Absorption, which is way too short for deeply-cycled lead batteries.  4-5 hours at Vabs is typical for healthy banks, and longer for injured/dying ones.

People with lead batts who don’t want MPPT are better off:

  • using plain shunts for deep cycle use, since you need all the absorption you can get anyhow; or

  • (relatively rare)  configurable PWM controllers for shallower cycling, maxxing out absorption duration if needed