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6.
Storage and Re-Commissioning
6.1.
Disconnect Batteries for Long Term Storage
For long term storage (i.e. 6 months or more) simply disconnect all sources of charge and discharging
from the battery bank.
6.2.
Self-Discharge & Maximum Period Between Charging
Although the batteries have a very low self discharge rate (≤2%/month, ≤12%/year) they should be
charged a minimum of every six months.
6.3.
Temperature & Humidity
Recommended: 15°C to 35°C, 45% to 75
％
Relative Humidity
Less than 1 month: -4°F to 113°F (-20°C to 45°C), 45% to 75
％
Relative Humidity
Less than 3 months: 14°F to 95°F (-10°C to 35°C), 45% to 75
％
Relative Humidity
6.4.
Avoid Using Trickle Chargers
Connecting a trickle charger is not recommended, unless the charger can be configured to stop
charging at 14.2V or below. Most trickle chargers are not sufficiently sophisticated to provide this
charge voltage ability. Over-charging the battery triggers the over-charge protection which shuts the
battery down until the voltage goes down enough by itself. Once that happens the trickle charger
would quickly raise the voltage up too high once again. As a result, the constant cycling of this
circuitry will shorten the life of the entire battery.
6.5.
Re-Commissioning
Prior to re-commissioning:
•
Ensure batteries are at 11.5-12.5V or 14.0 – 14.2V
When returning batteries to operation, be sure that the batteries are within operational range
prior to initiating charging and all exactly the same voltage. The exact same voltage must be
chosen between 11.5-12.5V and 14.0-14.2V (but not in the 12.6-13.9V range because the levels of
actual state of charge can vary with minute voltage differences). See the Pre-Installation
instructions above.
•
Ensure all batteries are within 0.2V tolerance
Verify the voltage of each individual battery to ensure they are still all within 0.2V of each other (or
less). If not, you will need to re-perform the charging step found in Pre-Installation.
Because of the nature of the voltage versus state of charge curve of the Lithium battery, the
voltage differences will be most pronounced with any of the batteries is nearly full or nearly
discharged (i.e. 14.0-14.3V or 11.5-12.5V). It is recommended to check that all voltages are within
0.2V of each other at these nearly full or discharged levels.
Checking voltage differences in the 12.6-13.9V region is not useful to ensuring all of the batteries
are really at the same state of charge (see Figure 1).
