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Great Planes Triton Charger - GPMM3150 User Manual

Page 28

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IMPORTANT - Manufacturers rate batteries in terms of “capacity” or “C,” which is usually listed in mAh
(milli-amp-hours). A battery’s capacity or “C” rating should be printed on its label.
Charge and discharge
currents are expressed as a function of this “C” rating. For example, a 500mAh battery has a “1C” rating of
500mA. To charge this battery at, say, 2C means the charge current should be (500 x 2) 1000mA or 1.0 amps.
To discharge this battery at C/5 means the discharge current should be (500 ÷ 5) 100mA. It is important to know
your battery’s capacity rating, because charge and discharge rates are typically expressed as a function of this
“C” value.

FOR LEAD-ACID AND LITHIUM-ION / LITHIUM-POLYMER BATTERIES, ALWAYS CONSULT YOUR BATTERY
SUPPLIER FOR EXACT CHARGE AND DISCHARGE SPECIFICATIONS AS PERFORMANCE VARIES BETWEEN
CELL MANUFACTURERS!

NiCd (nickel-cadmium) and NiMH (nickel-metal hydride) batteries:

Lithium-Ion (Li-Ion) and Lithium-Polymer 9Li-Po) batteries

CHARGING:
1.

Slow charge to break-in batteries that are new or
have been in storage for some time: set charge
current at 0.1C (C x 0.1), and set the “Safety timer” at
960 minutes.

2.

Quick charges:
a. N, AAA, AA and A size cells can safely be charged

at charge currents of 2C. A 600mA battery would
be charged at (600 x 2) 1200mA or 1.2A.

b. Most sub-C size cells can safely be charged at 3C.
c. Lower charge rates are less stressful on cells and

will extend service life. Reduce charge current if
battery overheats.

d. Set peak sensitivity to 8-10mV per cell for NiCd

batteries, and 3-5mV per cell for NiMH batteries.
Reduce peak sensitivity values if battery overheats
during charge. Read through the “Setup Menu”
section of Triton’s manual completely to
properly set all other charge parameters.

DISCHARGING:
1.

Discharge cutoff voltage: Set by multiplying the
number of cells in the pack by 0.9. Cutoff for a 7-cell
battery would be (7 x 0.9) 6.3 volts.

2.

To determine if a battery can deliver its rated
capacity:
Set discharge current at C/5. A 1000mA
battery would be discharged at (1000

÷

5) 200mA

or 0.2A.

3.

To determine a motor/power battery’s ability to
provide high currents: Set discharge current to 4C
max. A 1200mA battery would be discharged at
(1200 x 4) 4800mA or 4.8A. Larger capacity batteries
can be discharged at 5.0A maximum.

4.

To determine the useful flight time of Rx and Tx
batteries:
Set discharge current to 0.2 or 0.3A, AND
set the discharge cutoff voltage to 1.1 multiplied by
the number of cells in the pack. For example, a 4-cell
Rx pack would be set to (1.1 x 4) 4.4 volts.

Pb batteries (lead-acid):

CHARGING - Read Triton’s manual to properly set the
safety timer in the SETUP MENU:
1.

Battery voltage: Set “Pb charge” voltage to match the
voltage rating printed on the battery.

2.

Slow charge: Set “Pb charge” current at C/10. For a
7Ah (7000mAh) battery, current would be (7000 ÷ 10)
700mA or 0.7A.

3.

Fast charge: Set “Pb charge” current at C/3. For a
7Ah battery, this current would be (7000 ÷ 3) 333mA
or 2.3 amps.

DISCHARGING:
1.

Discharge cutoff voltage: Set “Pb discharge” voltage
to 1.75 multiplied by the number of cells in the
battery.

2.

To determine if a battery can deliver its rated
capacity: Set “Pb discharge” current at C

÷

20. A 7Ah

(7000mAh) lead-acid battery would be discharged at
(7000 ÷ 20) 350mA or roughly 0.4A.

CHARGING - Read Triton’s manual to properly set the
safety timer in the SETUP MENU:
1.

Battery voltage: Set “Li-Ion charge” voltage to be 3.6
multiplied by the number of cells in the battery.

2.

Slow charge: Set “Li-Ion charge” current at 0.3C.

3.

Quick charge: Set charge current at 0.7C. Some cell
brands may allow for a quick charge of up to 1C.
ALWAYS consult the cell supplier to confirm what is
an acceptable fast charge rate. NEVER overcharge
lithium batteries!!

DISCHARGING:
1.

Discharge cutoff voltage: Set “Li-Ion discharge”
voltage to 3.0 multiplied by the number of cells in the
battery.

2.

To determine if a battery can deliver its rated
capacity: Set “Li-Ion discharge” current at C/5 (C

÷5)

.

3.

For quick discharges: Set discharge current to no
higher than 2C maximum.

R/C BATTERY CHARGE/DISCHARGE RECOMMENDATIONS