Victron energy Smart BMS CL 12/100, Manual

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5
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4. Things to consider
4.1 Important warning
Li-ion batteries are expensive and can be damaged due to over discharge or
over charge.
Damage due to over discharge can occur if small loads (such as: alarm
systems, relays, standby current of certain loads, back current drain of battery
chargers or charge regulators) slowly discharge the battery when the system
is not in use.
In case of any doubt about possible residual current draw, isolate the battery
by opening the battery switch, pulling the battery fuse(s) or disconnecting the
battery plus when the system is not in use.
A residual discharge current is especially dangerous if the system has
been discharged completely and a low cell voltage shutdown has
occurred. After shutdown due to low cell voltage, a capacity reserve of
approximately 1Ah per 100Ah battery capacity is left in the battery. The
battery will be damaged if the remaining capacity reserve is drawn from
the battery. A residual current of 10mA for example may damage a
200Ah battery if the system is left in discharged state during more than 8
days.
4.2 DC loads with remote on/off terminals
DC loads must be switched off or disconnected in case of imminent cell under
voltage.
The Load Disconnect output of the Smart BMS CL 12-100 can be used for this
purpose.
The Load Disconnect is normally high (equal to battery voltage) and becomes
free floating (= open circuit) in case of imminent cell under voltage
DC loads with a remote on-off terminal that switches the load on when the
terminal is pulled high (to battery plus) and switches it off when the terminal is
left free floating can be controlled directly with the Load Disconnect output.
See appendix for a list of Victron products with this behavior.
For DC loads with a remote on/off terminal that switches the load on when the
terminal is pulled low (to battery minus) and switches it off when the terminal
is left free floating, the Inverting remote on-off cable can be used. See
appendix.
Note: please check the residual current of the load when in off state. After low cell
voltage shutdown a capacity reserve of approximately 1Ah per 100Ah battery
capacity is left in the battery. A residual current of 10mA for example may damage
a 200Ah battery if the system is left in discharged state during more than 8 days.