Page 605 - Battery Reference Book

51/42 Nickel batteries
Nife 1. 0.lC~ A for type H.
2. 0.05Cj A for types M and L.
Nife supply three versions of the vented nickel-cad-
mium battery, the H, M and L series, which overlap Discontinuous parallel operation, for example for
each other in performance. generator-charged starter batteries, normally uses short
The H cell (high-performance cell for short dis- heavy-current discharge or other shallow discharge.
charge times) has the thinnest plates and hence the The recommended charging voltage is:
greatest plate area per amount of active material.
The L cell (low-performance cell for long discharge 1. 1.50-1.55V/cell for types H and M.
times) has the thickest plates and hence the greatest 2. 1.50- 1.58 V/cell for type L.
amount of active material per plate area.
The M cell (medium-performance) has a plate thick- In buffer operation, where the load temporarily exceeds
ness between that of the H and L cells. Power and the charger rating, the recommended charging voltage
energy are balanced between the two extremes of H is:
and L. 1. 1.50-1.55V/cell for type H.
2. 1.55-1.60V/cell for types M and L.
Charging These batteries can be charged by all nor-
mal methods. Generally, batteries in parallel operation The following maximum charging current may be used
with charger and load are charged with constant volt- provided that the charger voltage limit is not higher
than 1.72 V/cell:
age. In operations where the battery is charged separ-
ated from the load, charging with constant current or 1. 5C5 A for type H.
declining current is recommended. High-rate charge 2. 2SCj A for type M.
or overcharge will not damage the battery, but exces- 3. 1.5Cs A for type L.
sive charging will increase water consumption to some
degree. Constant-current charging currents (Figure 5 1.3 1) are:
In constant-voltage charging (Figure 51.30) for con-
tinuous parallel operation with occasional battery dis- 1. Normal charging: 0.2C5 A for 7 h for types H, M
charge, the recommended charging voltages are: and L.
2. Recommended fast recharging: 0.4CjA for 2.5h
1. Float charge: followed by 0.2Cj A for 2.5 h.
1.40-1.42V cell for types H, M and L. 3. Minimum recommended charger rating for high-
2. High-rate charge: rate recharging: 0.1Cs A for type H; 0.05Cj A for
1.55-1.65V/cell for types H and M. types M and L.
1.55-1.70V/cell for type L. 4. Minimum recharging rate: 0.003Cj A.
5. Trickle charging rate: O.OOl-O.OO2C5 A. Adjust the
The minimum recommended charger rating for high- current value to achieve a charging voltage level of
rate charging is: 1.40- 1.42 V/cell steady state.

7 6 5 4 3 2 1
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Figure 51.30 Typical constant-voltage recharge characteristics for M-type cells available from Nife. Charging voltage (v/cell): 1, 1.40;
2, 1.45; 3, 1.50; 4, 1.55; 5, 1.60; 6, 1.65; 7, 1.70 (Courtesy of Nife Jungner)