Photovoltaic Batteries

Battery Components

Configuration

Manufacturers

Storage Batteries

In a photovoltaic system batteries store and deliver energy.

In this system batteries are most affected by the size and usage of the energy load.

Charge Controller

Batteries can easily be drained and damaged without regulation of energy loads.

Systems must be sized to match within load range (“voltage set point window”). e.g. Battery with 14 volts charged,11 when fully

discharged. If load will not operate below 12 volts.

Voltage window does not match that of the load.

Amp-hour capacity

Amp-hours: number amps of current can discharge x number of hrs it can deliver that current.

This attribute is very important to designers to determine length of operation without sunlight. e.g. 200 amp-hr battery should be able to deliver

200 amps for 1 hr, 50 amps for 4 hrs, 4 amps for 50 hrs, or 1 amp for 200hrs.

Depth of discharge

This describes how much of total amp-hr capacity of the battery is used during a charge and recharge cycle.

Most “shallow cycle” batteries discharge from 10% to 25% of their capacity.

Most photovoltaic batteries discharge up to 80% w/o damage.

Vented Lead Acid

Lead & Sulfuric Acid combination. Vents allow hydrogen & oxygen to

escape. The battery of choice for most

solar and backup power systems. Discharges up to 80%.

Details

Larger Plates, or more of them will increase amp hrs.

Thicker plates will prolong life of batt.

AGM or Gel Lead Acid Batteries Never need watering. Cannot freeze or spill. Does require very accurate regulation to

prevent overcharge and over discharge.

Nicad (Nickel Cadmium)

Pros Low self-discharge. Can totally discharge w/no damage. No freezing. Low Maintenance.

Cons Expensive to buy. Expensive to dispose of.(Cadmium is very

Hazardous)

Future Battery Prospects

Redox Battery- short for reduction-oxidation, which is a cycle of chemical reactions.

The lithium-metal sulfide battery operates at a temp. of almost 850F. Requires a special container to maintain that temperature.

A polymer battery is being developed,uses no liquid or dangerous materials, can be molded into any shape.

Batteries in Series & Parallel

Like photovoltaic cells, batteries connected in series increase voltage.

Connected in parallel to increase amp-hour capacity of the battery system.

Both series and parallel can be combined.

Manufactures

http://www.dcbattery.com/solar.html

Get quote. Great opportunity to compare manufacture

quality and price.

                                                                                           

           

ParallelSeries

Series &Parallel

Questions