What is an Amp Hour Meter

1
What is an Amp Hour Meter?

• (And why the heck do we need it anyway?)

2
"FEW BATTERIES DIE A NATURAL DEATH...MOST ARE
MURDERED"

• ----Unknown Industry Representative Source
  Sunelco Planning Guide

3

• 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

4
3 Types of Battery Metering

• 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

• 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!)

5
3 Types of Battery Metering

• 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.

6
3 Types of Battery Metering

• 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
7
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_a
mmeter.html
8
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)

9
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)

10
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

11
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 wouldnt drive a car long distances w/o a
  fuel gauge, now would you?