External Trickle Chargers
It is very useful to have an alternate means to charge 48V batteries.
Batteries are required to ship at low states of charge and may be slightly below turn on voltages, depending how long they have been warehoused by distribution.
Batteries may also dip below their turn on voltages if discharged down to low states of charge and not recharged after a period of time.
For example, an offgrid cabin without a generator autostart where solar charging has been disabled by snow and left unattended is a common deep discharge scenario.
Some inverter electronics cannot power up without battery voltage present.
In these cases, it can be difficult to recover from a deep discharge event.
Fortress batteries are programmed with a reserve capacity to help recover from deep discharge events - but programming can only go so far to mitigate the impact of energy fundamentals.
Caution: If the battery is below 10V, charge with a 12V trickle charger first.
Transition to 24V trickle charger before charging at 51-56V.
Charge at <5A when charging in these voltage ranges.
Do not charge the battery in freezing conditions.
One option that we have not yet tested is a 12V->56V boost converter. Keep your car running while using these or you could end up with a dead car battery!
When recharging a deep discharged battery, it may be necessary to force open the relay contactors of the battery.
This can be easily accomplished on the eVault MAX but eFlex and LFP10 MAX may require a firmwar eupdate tool or battery disassembly.
Please fill out a support ticket at https://support.fortresspower.com
prior to recovering a deep discharged battery.
very large busbars
When combining multiple batteries, the best practice is to parallel each battery (with similar length conductors) to a busbar. When outside of conduit, a cost-effective solution is the Victron "Power-In" or its fused cousin, the Victron "Lynx". ...