Download What is an Amp Hour Meter? (And why the heck do we need it

What is an Amp Hour Meter?
(And why the heck do we need it anyway?)
"FEW BATTERIES DIE A
NATURAL DEATH...MOST ARE
MURDERED"
----Unknown Industry
Representative Source:
Sunelco Planning Guide
• With proper care, quality batteries that are sized
correctly for your application will last for years.
• If abused, an expensive battery bank may last
only months.
• Taking out too much power without recharging is
what kills most batteries.
• Also, batteries that are low will freeze easily,
while a fully-charged battery is good to at least
30 below zero.
• "Deep-cycle" batteries are designed to resist
damage from repeated deep discharges (50% to
80% of capacity used up)...but will still last
significantly longer if discharged by only 20%
3 Types of Battery Metering
1. Voltage


Cheapest but least accurate.
Measure DC voltage across the main positive
and negative terminals (where the inverter
and/or solar panels are connected to the batteries).

As batteries age, the voltage reading gradually lowers
2. Specific Gravity
• Accurate, but messy
• You'll need a good battery hydrometer--it will look like a foot long glass
turkey baster with a glass float and thermometer inside.
• Open up one cell on each battery and suck out enough acid to float
the float
(Wear goggles and rubber gloves! Keep baking soda and water handy in case you spill!)
3 Types of Battery Metering
1. Amp Hour Meter



Measures the flow of current into and out of the
battery
As you use power, the meter counts how many
amp hours are used.
As the battery is charged, the meter goes
backwards, toward zero.
3 Types of Battery Metering
1. Amp Hour Meter



Measures the flow of current into and out of the
battery
As you use power, the meter counts how many
amp hours are used.
As the battery is charged, the meter goes
backwards, toward zero.
Think an Amp Hour Meter as
a fuel gauge for your battery bank
A SIMPLE AMMETER
Here is a simple way to make a reliable, safe ammeter
for ... ? I use mine to monitor power coming into/out
of my batteries. Undoubtedly one could make many
modifications; it would not be too difficult to convert
this to a full function multi-meter. Mine shows DC
amps, plus or minus 15. This meter is simple, and
reliable enough to serve many applications. With
just a little work, it could be a fine addition to any
shop, or living room.
The meter consists of a wooden back, a
long wooden needle(14" long), which
pivots on a nail. To the bottom of the
long wooden needle is a surplus
computer hard drive magnet glued on
with super-glue. You can get the magnet
out of most computer hard drives, or...we
sell them, between $1 and $12,
depending upon the scale of meter you
have in mind.
http://www.otherpower.com/otherpower_experiments_ammeter.html
Tri-Metric 2020 Battery Monitor
Amp-Hour Meter
• For 12-24v systems (48v with
adapter)
• Reads volts, amps, and amp/hours
on an LED display
• Can also display “percent full”
• LED light flashes when batteries are
fully charged
• LED light for when batteries have
very low charge
• Records voltage history
• $175-$189 ($30 adapter)
Trace TM-500
Amp Hour Meter
•
•
•
•
•
•
•
For 12-24v systems (48v with adapter)
Reads volts, amps, and amp/hours on an LED display
Easy installation with custom shunt cable
Provides estimated battery life information
Shows days since full
Highest and lowest voltages
$195 - $250 ($40 adapter)
Xantrex Link 10
• For 12-24v systems
• Scrolls through Volts, Amps, Amp-hours / kilowatt-hours
and Time Remaining w/ multi-color bar graph
• Easy installation with custom shunt cable
• Provides estimated battery life information
• Shows days since full
• Highest and lowest voltages
• Reports kilo-watt hour consumption
• “Sleep” mode
• $250 with shunt $210 w/o
WHY??
• Maximize the life of your batteries
• $200 compared to replacing a quality
battery bank is cheap.
• You can tell the condition of your batteries
at a glance
• You wouldn’t drive a car long distances
w/o a fuel gauge, now would you?