I have a SureStart "soft start" kit for sale, Hyper Engineering part # SS1B08-16SN. $200 including shipping. This is a good addition to any A/C unit to extend its life, but it's essential for starting an A/C compressor with a limited number of Powerwalls. I used this on a heat pump with two PW's for about a year, and it worked great. I've now replaced that heat pump with a variable-speed unit that has an inverter and doesn't need the soft-start. Be sure this is the right size SureStart for your system, based on your A/C's RLA. For example, my heat pump had an RLA of 14, so the SureStart model for me was the one with the 08-16 in its part number. A larger unit might need the one with "16-32" in the model number.
Product details here.
Product details here.
