Solar batteries are the most costly component of any off-grid solar system. It’s important to program them properly and stick to a regular battery maintenance schedule to keep them running efficiently for years. Neglecting the proper setup and maintenance routine can shorten the lifespan of your solar panels batteries and void the product warranty.

Some battery types, like Lithium-ion, require little to no maintenance after the initial setup. Other battery types (especially flooded lead-acid) need regular upkeep to stay in good condition.

No matter what type of batteries you own, this article will help you program your battery bank and give some battery maintenance tips to keep your system running smoothly.

The first time you bring your system online, you’ll need to program your battery chargers to the proper charging settings for your battery bank. These settings dictate parameters like charging voltage and current.

This is where you program voltage set points, the charging voltages applied to the battery during each stage of the charging cycle. Batteries typically charge in 3 phases—bulk, absorb, and float, which can be summarized as follows:

Bulk: High current to replenish charge and bring voltage up as quickly as possible (below 80%)

Absorb: Charge rate slows as batteries approach full state of charge (~80-100%)

Float: Batteries receive a trickle charge at 100% to stay fully charged

Each stage requires the charger to be set at a specific voltage, which is based on the requirements of your battery.

Programming the voltage set points accurately is critical to ensuring the long-term health of your batteries. Setting the wrong charge parameters will make your batteries charge improperly, shortening their lifespan.

There are other values to set during the initial programming phase as well:

Absorb time: The amount of time the charger spends in the absorb phase.

AC input amps: Maximum input current from grid or generator, to ensure the combined current from the battery charger and loads doesn’t exceed the rating of the generator. Depends on generator size or grid input breaker. See manual for details.

Max charge rate or charge current limit: Maximum charging current, either expressed as a percentage of the charger output or total maximum charging amps. This setting is used to limit charger output, to make sure your batteries are not overcharged with too much current.

Temperature compensation: Adjusts the battery charger for operation in various temperature ranges. Most chargers include a battery temperature sensor.

These settings are different for every battery and charger. Check the spec sheets or installation manuals for your batteries and chargers to find the specific values for each of the above settings.

Programming your equipment according to the settings recommended in the manual is the first step toward ensuring the long-term health of your battery bank.