Xantrex Truecharge 20+ Amp Owner's Manual - page 37
About Charging
3–3
Battery Temperature
Temperature
switch
Selecting the correct temperature setting selects the appropriate charging
voltage to compensate for battery temperature.
Effect of
temperature
Cold battery temperature
If you choose the Cold setting,
Truecharge + delivers, for example, 14.8 volts in absorption mode and
13.9 volts in float for a Flooded battery.
Hot battery temperature
If you choose the Hot setting for the same
battery, the charger delivers 14.0 volts in absorption mode and 13.1 volts
in float, nearly one volt of difference from the cold battery charge.
Consequence of wrong selection
If you choose a cold temperature
setting for a hot battery, you risk overcharging your battery. If you are in
doubt about which to choose, or if you are leaving the charger connected
for an extended time, select Hot to reduce the risk of overcharging. The
same is true for Gel and AGM type batteries. The life of your battery will
be extended if all banks are in a similar temperature environment and you
make sure the switch setting is correct each time you charge. You should
consider purchasing a Xantrex battery temperature sensor if you expect
wide temperature fluctuations.
13.8/13.4
Cold
Warm
Hot
14.4/13.5
14.0/13.1
14.2/13.8
Output Volts
Absorption / Float
14.6/14.2
14.0/13.1
14.3/13.4
14.6/13.7
14.8/13.9
Battery Temperature
COLD
(below 50°F/10°C)
WARM
(50°F/10°C to 80°F/27°C)
HOT
(above 80°F/27°C)
Battery Temperature
Selector Switch