Recommendation: Category G5

Recommendations on category G5

Test procedure for category G5:

NFC58-510 plus PPER (Combined test procedure, ageing ratio 1:1)
See Testprocedures and ref. [3])
As long as no results are available for this combined test procedure, select the battery that has the best results (longest life time) for the two separate test procedures.

Selection of battery and charge controller for category G5:

  • It is essential to use a charge controller that protects the battery from overcharging. The recommended end-of-charge-settings of the controller depend on the type of battery and the category of battery usage. The recommended batteries are given below, in order of preference, together with the recommended voltage settings for the charge controllers at charging.
    Recommended battery
    in order of preference
    Controller settings(in V/cell at 25°C) maint.
    months
    Flooded, industrial
    flat plate with
    electrolyte mixing
    Charge: 2.45 V ( 2h / day)
    Float 2.35 V
    equalisation: 2.55 V (8h / 2 weeks)
    6
    VRLA, flat plate Charge: 2.45 V (2h / day) Float 2.35 V
    equalisation: 2.5 V (10h / month)
    12
  • It is essential to use a charge controller that protects the battery from deep discharging. The control algorithm of the charge controller can be based on a SoC calculation or on voltage settings. The recommended end-of-discharge-settings of the controller are the following:
    • Low voltage Disconnect, for discharge current I10: 1.80 to 1.85 V/cell
    • Low voltage Disconnect, for discharge current 10% of I10: 1.95 to 2.0 V/cell
  • If the battery will be operated outside the temperature range of 20-30 degrees it is preferable to use a charge controller that compensates for the effect of the battery temperature. It will typically adjust settings to ensure that charge and discharge cycles are modified based on temperature and voltage or state of charge. A separate battery temperature sensor should be used.
  • It is preferable to use a charge controller with separate voltage sense terminals.

More specific recommendations for category G5:

The operating conditions of the battery in category G5 are good. Only in case of flooded batteries a small increase in the charge factor would be beneficial.
The following recommendations are made:

  1. Apply the recommended values for the setpoints of the charge controller in the table above.
  2. Use a charge controller with a low self-consumption and with a high efficiency.
  3. 2. Reduce the load (e.g. by replacing appliances by more efficient ones).
© ECN-DEGO. Last update: 27-dec-04. For information: dego@ecn.nl
Energy research Centre of the Netherlands (ECN) P.O. Box 1, 1755 ZG Petten, tel. +31 224 56 49 49