With increasing competition in the battery industry going with a Tesla Powerwall 2 or a Generac PWRCell is a hard choice. Today we break down which is better at what, and the main differences.
Tesla’s compact size makes it suitable to fit in tight spaces smaller homes. They come in at 30 inches wide, about 5 inches thick, and right over 45 inches tall. Teslas are about 251 pounds and can be placed on the wall or secured on a flat floor. The PWRCell dimension is a cabinet of 5′ 10″ inches in height, 22 inches in width and 10 inches thick. It is notably larger than a Tesla Powerwall and usually goes inside a garage or in an enclosure. The biggest factor for batteries is the temperature they undergo. It is best to maintain batteries at a moderate temperature for max performance.
The Powerwall has 13.5 kWh worth of energy storage. For most homes, 13.5 kWh will be enough for 24 hours for essential loads. 200 amps panel services can have whole home back with two Powerwalls and enough solar. Generac does have many entry price points that allow for flexibility and customization for homeowners. The 9 and 12 kWh package does have comparable pricing to Tesla. The thing that makes Generac pricey is needing to buy that 7.6 kW inverter on all Generac installations.
Battery Safety and Chemistry
Tesla is a NEMA 3R rated battery meaning it can be installed inside and outside. However, we usually recommend that the battery go indoors. Generac makes two versions which can go either outside or inside.
Tesla Powerwall Battery Power
The Powerwall has a continuous 5000-watt power rating and a 7000-watt peak rating to help start larger loads. 5kW will get those essential items going but we do not recommend having one battery for an HVAC system. This can potentially flip the breaker and not turn on the appliance.
Generac PWRCell Battery Power
Now the capacity for the PWRCell is a bit tricky so we will be putting a graph up. You see that starting with a 9kWh battery will get you 4500 watt continuous and 6000 watts peak for 2 seconds. For every additional battery module, you get an extra 1500 watt continuous and 1920 watt peak for 2 seconds. A 9 kWh battery generates 20 hours worth of backup for an essentials loads panels. A fridge, some lights, and a wifi system are common to back up. At 18 kWh max capacity you have over 9kW of continuous power. We also get 12 kW of peak which is usually enough for large loads and great for suburban homes. Some air conditioners that have low amperage kick start can also be backed up. We recommend installing a soft start to power the HVAC systems or adding two cabinets for larger HVACs.
Battery Warranty / Life
Generac is expandable as well and increases in power and capacity. The system does have a 10-year standard leading warranty. There are rumors this will increase to 25 years but that is yet to be released. This is not a limited warranty though, so there is no guarantee of a certain battery charge after ten years. Tesla comes in with a 10-year warranty which is quite standard in the industry. It has to be at 70% charge when those 10 years come
Tesla is compatible with various inverters like SolarEdge and Enphase while Generac is only compatible with the Generac inverters.
Generac does have many entry price points that allow for flexibility and customization for homeowners. The 9 and 12 kWh package does have comparable pricing to Tesla. Generac does have many entry price points that allow for flexibility and customization for homeowners. The 9 and 12 kWh package does have comparable pricing to Tesla but the required inverter makes the purchase more expensive.
Whole Home Back Up
Every 200 amp panels can have whole home back with two Powerwalls and enough solar. A PWRCell system can back up an entire home. However, it must be paired with smart management modules and soft starts.
Customer Battery Complaints
Timeline delays have proven to be a big complaint about Tesla Powerwalls. Not being able to charge at the press of a button during emergencies are too. A Generac complaint is PV links may burn out for overloading them with more than the max of 2500 watts. Always make sure the installer knows how to properly install these complex systems.
Generac and Tesla Battery Best Feature
Tesla’s ability to have such a large capacity and power surge per unit is a huge selling tool. Generac’s key feature is the ability to start small and expand overtime. The ability to also add a second cabinet to the same inverter is convienient and can save the homeowner money.
We are excited to analyze how the Tesla Powerwall 2 vs Generac PWRCell compete head-on and what each brings to the industry. Now is the time for as many homes and businesses to adopt battery back up storage.