Unless you are going to install enough solar panels to power your entire house, and most of the time not even then, there is almost no reason ever to use batteries on a solar installation!
If there's no batteries, the extra power that can be saved in day time are wasted. Batteries are necessary, it keeps extra power to compensate in cloudy days and evenings. It's especially necessary for CONSTANT BITCOIN MINING RIG.
AND SOLARMINER use LFP batteries not the batteries used in cars! For those who are experts will know why.
For those who don't, here's the quotes from wikipedia:
The LiFePO4 battery uses a lithium-ion-derived chemistry and shares many advantages and disadvantages with other Lithium-ion battery chemistries. However, there are significant differences.
LFP chemistry offers a longer cycle life than other lithium-ion approaches.[7]
Like nickel-based rechargeable batteries (and unlike other lithium ion batteries), LiFePO4 batteries have a very constant discharge voltage. Voltage stays close to 3.2V during discharge until the battery is exhausted. This allows the battery to deliver virtually full power until it is discharged. And it can greatly simplify or even eliminate the need for voltage regulation circuitry.