Solar Energy Generation Systems – an overview by Specialized Solar Systems
BATTERY STORAGE
Battery technology is progressing in leaps and bounds. Three main categories of batteries could be supplied:
- Lead acid
- Sealed
- Gel
- AGM
- Flooded
- Lithium iron phosphate
- Zinc bromide
Each battery technology should be managed within its own format. Not all batteries are the same and it is of utmost importance to understand how this technology is used to service the energy needs of your system.
Storage technology is controlled by voltage. The voltage applied to the battery will determine what the battery will need to store or supply. Lead acid will have a different voltage supplied to ensure that the charging of the technology is ensuring maximum effect. An example of this would be the different stages of charge required for a lead acid battery:
Bulk charge
- Absorb charge
- Float charge
- Equalization charge
| depending on the type of lead acid and the temperature the voltage percentage will be set |
If those voltages are not set correctly, damage or lack of storage could occur. All these voltages will have been preprogramed into your DC-DC control.
The discharge of lead acid batteries can also be evaluated by voltage. If the battery is being charged from solar then the voltage reading is not necessarily the real battery voltage, but the charge voltage. If you are discharging the lead acid battery into your load then this voltage is the discharge voltage. To ascertain the real voltage of a lead acid battery you need to disconnect the charger and the load and allow it to settle for a period (30 mins), at that time you will be able to measure the real voltage of the battery. The real voltage will indicate the condition of the battery at that time. Each battery has its own voltage criteria, so please refer to your charge controller manual to know what your battery reading should be.
Examples of Lead Acid Battery Condition
12.75V Full
12.5 50%
12.2 60%
12.02 flat
| x 2 for 24 V x 4 for 48V |