Keywords:
ModelGauge, EZ, MAX17201, MAX17205, MAX17211, MAX17215, m5, fuel gauge, gas gauge,
fuelgauge, coulomb counter, battery
APPLICATION NOTE 6263
HOW TO FUEL GAUGE LITHIUM-ION
BATTERIES WITHOUT BATTERY
CHARACTERIZATION WITH MODELGAUGE M5
EZ
Abstract: This application note discusses how to use ModelGauge m5 EZ with an associated EV kit to
enhance and increase fuel gauging, eliminating battery characterization. Simply connect the battery and
start reading the fuel gauge registers, with minimal or no configuration.
Introduction
The ModelGauge
m5 EZ makes fuel gauging easier than ever before. Simply connect the battery and
start reading the fuel-gauge registers with minimal or no configuration.
For conventional fuel gauges, battery characterization is a mandatory requirement to get acceptable
performance because of the large distribution of the electrical properties presented by a wide array of
Lithium-ion chemistries available in the market. Even for batteries with the same chemistry such as the
popular lithium cobalt oxide (LiCoO
), different form factors change the impedance in the batteries that
traditionally makes battery characterization a necessary step. For some projects with schedule pressures,
the two-three weeks of characterization/data analysis time can be unacceptably long.
The ModelGauge m5 EZ configuration eliminates the need for battery characterization, saving resources
and time. It can deliver excellent fuel gauge performance across many different battery chemistries,
capacities, and charge voltages. This has been tested on hundreds of batteries in Maxim’s
characterization database.
ModelGauge m5 EZ Performance
Figure 1
shows an accuracy table of ModelGauge m5 EZ on 300+ batteries tested at +20°C and +40°C
with a run time greater than 3 hours.
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2
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