John Drake Services, Inc.
1427 E. 68th Street
Long Beach, CA 90805
electricity from the sun by John Drake II | home
About Us | About this website. | Getting Started | Solar Panels / Photovoltaic Modules - Read Before You Buy | Make A Plan | PV System Layout and Parts | Start with the loads you are going to operate | Battery Types and Sizing | Battery Safety | Battery Charging Voltages and Temperature | Battery Trouble Shooting | Charging Batteries - You can't have everything. | Battery State of Charge and Measurement | Safety Devices Fuses and Circuit Breakers | Series & Parallel Wiring | Wiring and Power Distribution Connections | Photovolatic Module Specifications - Real or a Pipe Dream | Photovoltaic module solar panel location and positioning | Photovoltaic Module and Solar Panel Information | Charge Controller Types | Wire and Cable Types | Wiring - Doing it Right | Connections for Wiring | Voltage Drop - Wire Loss, What are they? | Outdoor Connections | Wire loss - Voltage drop charts | D.C. to A.C. Inverters | Low Voltage D.C. Lighting & Color Temperature of Light | Battery System Monitoring | Dont fool yourself - Spending your money wisely. | Solar Converters GS-1AC | Linear Current Boosters for Water Pumping | Utility Grid Intertie Systems | Solar Insolation Chart | More Information | Alternative Energy Expectations | Power Needs Worksheet | Reference Sources | Contact Us
Battery Trouble Shooting
Batteries, like people, wear out.
Their life span and operating characteristics on how they are worked as well
as how well they are maintained.
Here we will be dealing with flooded lead acid batteries.
Many of the observations here also apply to sealed batteries.
How do batteries age?
A new battery starts out with nice clear electrolyte, unblemshed lead plates with
clean pores and an empty sediment tray in the bottom of each cell.
As they are being used (discharged), the acid in the electrolyte moves into the pores in the
When they are being recharged the acid migrates back into the electrolyte solution.
If the acid (sulfuric) stays in the plates too long the pores will become plugged up with
This can permanently reduce battery storage capacity as well as the ability to recover
from a heavy amp draw.
If distilled water is not regularly added to the cells the electrolyte level can go below
the lead plates which can cause a coating of lead oxide to form on the plates.
This coating can insulate the plates from the electrolyte and reduce the capacity
of the batteries.
As a battery ages the surface of the lead plates slough off and fall to the bottom
of the cells.
The sediment tray in each cell is designed to keep the lead sediment from shorting
out the bottom of the plates.
This can be accelerated by beating the daylights out of your batteries on a
For giggles lets imagine the battery in your car is not acting right.
You take it into the shop and they decide to run a load test.
The mechanic (yes I am old school) will hook up a load tester.
The starting voltage of the battery is read.
The load tester will use a resistance load to pull power out of
your battery for so many seconds and read the voltage again.
After a short period of time the voltage will be measured again.
The following voltages are being pulled out of my hat for example only.
Let's say that the starting voltage was 12.75 volts, then right after the
load it was 11.5 volts.
After resting it comes back up to 12.0 volts.
That is not such a great recovery voltage.
The more worn out the battery is, the wider the gap will be between the
starting voltage and the measured voltage after it has rested.
You can do this type of testing yourself by turning on loads in your system.
As batteries age they lose capacity and don't recover fom heavy loads as quickly
as they did when they were young, kind of like us.
When I used to rehab existing systems, I would do this to show the system owner
the shape the battery bank was in - more often than not it was ready for the
What can you do to get the most out of your battery bank?
The first step is to size both the battery bank and charging source to meet your
All too often the solar panels, batteries or both are undersized to meet the economic requirements
of the user.
If you start out with a small system and plan to expand, it is best to limit your loads
(power consumption) to the current capacity of the system.
to be continued