Table of Contents
Advertisement
Some lithium battery chargers stop charging when the current drops below a set threshold. The tail current must be set higher in
this case.
Peukert exponent
In VictronConnect see: Settings > Battery > Peukert exponent.
Via the head unit, see: Setup menu > Setting 05 - Peukert exponent.
When subjected to high discharge rates, lithium batteries perform much better than lead-acid batteries. Set the Peukert exponent
at 1.05, unless the battery supplier advises otherwise.
Charge efficiency
In VictronConnect see: Settings > Battery > Charge efficiency factor.
Via the head unit, see: Setup menu > Setting 06 - Charge efficiency factor.
The charge efficiency of lithium batteries is much higher than that of lead-acid batteries. We recommend setting the charge
efficiency at 99%.
Discharge floor
In VictronConnect see: Setting > Battery > Discharge floor
Via the head unit, see: Setup menu > Setting 16 - SoC relay.
This setting is used in "the time to go" calculation and is set at 50% by default for lead-acid batteries. However, lithium batteries
usually can be discharged significantly deeper than 50%. The discharge floor can be set to a value between 10 and 20%, unless
the battery supplier advises otherwise.
Important warning
Lithium batteries are expensive and can be irreparably damaged due to very deep discharge or overcharge.
Damage due to deep discharge can occur if small loads slowly discharge the battery when the system is not in
use. Some examples of these loads are alarm systems, standby currents of DC loads and back current drain
of battery chargers or charge regulators.
A residual discharge current is especially dangerous if the system has been discharged all the way until a low
cell voltage shutdown has occurred. At this moment the state of charge can be as low as 1%. The lithium
battery will get damaged if any remaining current is drawn from the battery. This damage can be irreversible.
A residual current of 1mA for example can damage a 100Ah battery if the battery has been left in a discharged
state for more than 40 days (1mA x 24h x 40 days = 0.96Ah).
The battery monitor draws <48mW from the battery. The positive supply must therefore be interrupted if a
system with Li-ion batteries is left unattended during a period long enough for the battery monitor power
consumption to completely discharge the battery.
In case of any doubt about the possible residual current draw, isolate the battery by opening the battery
switch, by pulling the battery fuse(s) or by disconnecting the battery positive when the system is not in use.
Page 14
Manual - BMV-700H
Configuration
Advertisement
Table of Contents
