Why We Chose The Batteries That We Use
There are two battery types commonly used with solar: lead-acid and lithium-ion. Each type has its pros and cons:
Lead acid has a lower cost per kWh, excellent surge capability, can withstand cold temperatures, and are readily available. However they are very heavy, somewhat large and have a lower cycle life compared to lithium.
Lithium has a very high energy density and extremely long cycle life, however they have a high cost per kWh, often lower surge capability and suffer substantial capacity loss in below freezing temperatures.
The standard battery for solar applications is lead-acid, however, with the advent of low cost wall mounted lithium packs, we’re seeing more of a mix of both chemistries.
At Mountain View Solar, we will choose the battery type that makes the most sense from a technical standpoint for a given application. We consider space, power requirements, operating temperature, cost and equipment availability amongst a few important design considerations.
When it comes to lead-acid, quality matters. Mountain View Solar uses DEKA/East Penn lead acid batteries, which are American Made using a sustainable manufacturing process. Most of the lead in DEKA’s new lead batteries is recycled from old lead batteries.
The lead batteries that we use are of the deep cycle variety, meaning they are built with thicker plates to withstand heavier use. Compared to a typical starting battery, they are much more robust and capable when drawn down repeatedly. Additionally, they are sealed or SLA type lead-acid. We do not install flooded batteries which emit dangerous gases and can leak acid.
For most lead systems we use the DEKA Unigy II line, an industrial AGM bank consisting of a single string of 2v cells. This battery bank is rated at 1800 cycles at 50% DOD, and can sit on stand-by for a decade or more!
For lithium backup systems, we use the SolarEdge “StorEdge” and LG Chem wall mounted solution. This turnkey 9.8kWh backup solution can handle most small appliances with ease. The LG battery is rated for 27.4MWh of energy throughput and warrantied for 10 years.
Mountain View Solar has the most off-grid and battery backup experience in the mid-atlantic area. Our systems are clean and compact, built to last over twice as long as competitor’s designs.