Batteries is one of the most important element in a solar power system. Is here where electrical energy in a chemical form is stored for later use. This is the one part of your system that can be harmed by negleted or misuse. The standard battery for home made electricity is the Lead-Acid, it can be discharge to 50% and then recharge back to 100%, giving the advantage of using it for years, however, is a very delicate component, because if we do not take proper care, it could be damage to a point where it has to be discarded.
Battery bank in the size of 1000 to 2000 amp-hour 12 volts, 24 volts and 48 volts is desirable because a larger bank can accept faster charging by generator and give high power discharge from inverter surge without strain, specially in areas were the sunshine is not abundant.
The type of battery that you have to use in your solar energy project is the DEEP CYCLE. This type of battery can be discharge down to 50% and recharge back to 90 or 100% if charging is precisely controlled. The following types of batteries are commonly used in PV systems: Lead-acid and Alkaline.
Batteries characteristics for a solar energy system
A solar system energy designer, must consider the following characteristics before installing the batteries, particularly if this will be a stand-alone photovoltaic system.
Days of autonomy.
Time of discharge - Deep cycle.
Choosing a location for your bank of batteries.
Security measure to treat batteries.
Days of autonomy
Days of autonomy means the number of days that the batteries will provide energy withour receiving inmediate charge from solar modules, wind generator or other source of energy producer, for example gasoline or diesel generator.
The solar system energy designer must consider the location of the system, which elements will be used (e.g. lightand all kind of equipment or apparatus that require electric energy), to determine how many days of autonomy could be necessary for the project.
Climatological conditions and sunny days, are the principal factors determining how to calculate the number of days, that you can use your solar energy system, without worry about the charge that the bank of batteries must receive from the solar panels.
Contact JD solar for help in determining the number of batteries for your solar energy project. We help you with the best solution.
The capacity of the battery is measure in Amp-Hours.This is based on how much power we need for our
electric energy project.
In theory, a 100 amps battery will deliver one amp for 100 hours or roughly 2 amps for 50 hours before is considered fully discharge.
These are some of the properties that affect in one way or
another the capacity of a battery: Temperature, age, how is recharged
and quantity of load connected. We, at JD Solar, do not recommend mixing new batteries with old ones, the reason is that old
batteries could damage the new ones, because their resistance increase as they get older.
After planning and sizing a solar electric system, the batteries
should have a little more of capacity for the system, the reason is that
when batteries get older, they start-loosing some of its capacity.
Time of discharge.
The time a battery takes to discharge, affect directly its
capacity. this is a very delicated situation because if the battery or the bank
of battery discharge at a very rapid rate, we could have less capacity available for the system and on top of that, if the construction
of the battery is not of good quality, then it means that it has to be replace very soon, meaning more money to be spent (This is not good
for the system user).
If the discharge rate is slow, then the battery or the bank of
batteries could have enough capacity available for the system, decreasing
the possibilities to be replace (this is a good for the system user), and their life time also is increased, making our solar energy project
Important note: Always check recommendation from the manufacturer.
Years using it? age? no. Many
people think that the life of the battery or the bank of batteries depend on how
many years it is used, but
this is not the case. Batteries manufacturers determine the life of batteries in term of number of cycles (charge and discharge).
Batteries loose capacity with the time charging and discharging, and are considere on its final days when they loose 20% of its total
capacity of its original charge. For example, if you buy a 12 volt battery with 200 amps-hours capacity, and connect it to your solar
energy system and then in time notice that it has lost 20% of its original charge on the process of charging and discharging, then this
is the time to think about preparing a funeral for this battery eventhough can still be used for a while. Sometimes if we are lucky,
is possible to recycle it.
In theory, a battery that
experience a shallow cycle (discharging only 20%) of its charge, could last
4,000 cycle, while a battery
experiencing a deep cycle of 80%, only will last 1,500 cycle. In term of time, the life time of a battery experiencing a shallow cycle,
could last for about 10.5 years, while the one experiencing a deep cycle, could last only about 4.5 years.
However, remember that this is only a estimate, there are batteries on the market, that could stand up to two discharge daily.
Remember always to check with JD Solar. We alway have something good related to solar energy, for your home or business.
Choosing a location for your bank of batteries
Batteries are very sensitive to temperature.
Manufacturers, generally advice of keeping batteries in places, where
does not exceed 77° farenheit, and void low temperature (32° farenheit). At this temperature could be difficult to charge a
battery to its normal capacity.
Batteries have to be in places where it can receive
some ventilation, in a rigid enclosure. They are the most delicated elements, in
a photovoltaic system. It is the only element in the whole system that need the most attention, because if we don't take appropiate
care, It could last for a very short time.
Security measure to treat batteries
Batteries in general, are very dangerous elements. Dangerous
chemichal, weight, high voltage and current, are properties that add
together to cause electric shock if it is not properly handle. Technology is constantly getting better on batteries construction and
we recommend our customer to check the internet for the latest innovations on batteries construction.
The following rules should be applied when working with batteries.
- Do not work with batteries using
jewelry or metal on your body.
- Always use appropriated tools.
- Design the area where batteries will be located, with ventilation.
- Use appropriated clothes while working with batteries.
- Be sure to discharge yourself of static electricity before touching the batteries poles.
- Disconnect the bank of batteries from the load center before doing any job with the bank of batteries.
- Use the instruction manual from the manufacturer.
- Use common sense.
This site was updated on 08/18/2017