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_ammeter.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 wouldn’t drive a car long distances w/o a fuel gauge, now would you?