User's Manual
11 ·
MC3000
· 10
MC3000
BATTERY KNOWLEDGE
What Does 0.5C, 1C, -C/4, Etc Mean?
It is a short way of specifying charge transfer rates as function of battery capacity. Substitute the
nominal capacity for "C", divide by 1h, then multiply with the factor. For example, 0.3C for a
2100mAh battery equals a charge rate of 630mA or 0.63A (= 2100mAh/1h * 0.3 ), -C/4 or -0.25C
for a 3400mAh battery equals discharging it at 0.85A.
Choosing The Right Discharging Rate
The battery industry defines the so-called "standard discharge" as a constant current -0.2C
discharge at room temperature; per definition, discharging a fully charged new battery under
these conditions will yield its nominal capacity. Furthermore, battery manufacturers often list
minimum or rated capacities at higher, more typical discharge rates such as -0.5C or -1C in the
specification sheets. Yet a more common practice for analyzing and comparing batteries from
different sources is to always assume the same fixed discharge current, -0.5A or -1.0A, i.e.
decoupled from the nominal capacity.
Choosing The Right Charging Rate
Rechargeable Li-batteries. Battery manufacturers define the so-called "standard charge" most
often as a 0.5C charge at room temperature. The user is advised to look up the confirmed details
in the battery specification sheet.
Rechargeable Ni-batteries. Charging too fast may damage the battery and not charge as fully,
whereas charging too slow requires longer time and may prevent the charger from terminating
correctly. Hence charging at a rate below 0.3C or above 1.0C is not recommended unless
otherwise indicated. In case of doubt, adhere to indications on the battery wrapper, look for the
spec sheet, visit candlepowerforums, or call the battery manufacturer and ask for the optimal
charging rate.
Battery Matching
As a general rule, do not mix batteries of different types, different capacities, different voltages, or
from different manufacturers in a multi-cell application. Use the Refresh mode to determine
capacities of the same battery product, then group matching cells within ±5% of the measured
capacity. Unmatched batteries in a multi-cell application can lead to reduced performance or
runtime, or ultimately to battery damage, over discharge or reverse polarity.
Battery Forming Charge
NiMH/NiCd batteries, new or stored for extended period, can become chemically deactivated.
Battery forming charge is a charge-discharge-charge cycle which forces a full charge into the
battery at a very slow rate. This process reactivates the battery. In certain cases, it needs to be
repeated two or three times. Battery forming charge can be emulated by using the Break_in mode
with the C>D>C sequence. For very best health and condition though, cycling two or three times
at standard charge/discharge rates may be more effective.
BATTERY VOLTAGES
Battery manufacturers commonly specify recommended charge and discharge rates in datasheets
dependent on minimum, rated, typical, or nominal battery capacity. In practice it is easier to
compare the performance of different batteries by choosing a fixed pair of convenient rates, for
example either 1.0A/-0.5A or 1.0A/-1.0A, and reusing it for all batteries of similar or not so similar
size or capacity. In most cases it is not necessary to alter the default values. In fact, it is
dangerous to increase the maximum charge voltage of Lithium-Ion batteries, and it is bad for
battery health to discharge below the minimum discharge voltage.
NiZn
1.65V
1.90V
1.80~1.95V
OFF
1.78~1.88V
n/a
n/a
0.5C
≤1C
0.2C
1~10C
1.00V
1.30V
0.50~1.50V
NiCd
1.2V
1.65V
1.47~1.80V
OFF
1.30~1.45V
n/a
n/a
0.1~0.5C
≤1C
0.2C
0.5~2C
0.85V
0.90V
0.50~1.10V
NiMH / Eneloop
1.2V
1.65V
1.47~1.80V
OFF
1.30~1.45V
n/a
n/a
0.5C
≤1C
0.2C
0.2~2C / 0.5~3C
0.95V
1.00V
0.50~1.10V
LiFePO4
3.2V
3.60V
3.40~3.65V
OFF
3.38~3.58V
3.30V
3.15~3.40V
1C
≤4C
0.5C
1~8C
2.00V
2.40V
2.00~3.15V
LiIo4.35
3.8V
4.35V
4.10~4.40V
OFF
4.08~4.33V
3.90V
3.75~4.10V
0.5C
≤1C
0.2C
0.5~2C
2.75V
3.30V
2.65~3.75V
LiIon
3.6V 3.7V
4.20V
4.00~4.25V
OFF
3.98~4.18V
3.80V
3.65~4.00V
0.5C
≤1C
0.2C
0.5~2C
2.50V
3.00V
2.50~3.65V
Nominal voltage
Charge voltage max.
(range)
Restart voltage
(range)
Storage voltage
(range)
Standard charge
Rapid charge
Standard |discharge|
Typical |discharge|
Disch voltage min.
(default)
(range)