Part 68 (1/2)
1. Ampere-hour meter hand reaches FULL, or
2. Both pilot b.a.l.l.s are UP, or
3. Hydrometer test shows top of FULL band out of electrolyte.
In any case, plant should be run until battery is ”Charged” at least once a week.
Always Start Charging When Battery Gauges Indicate Battery Discharged.
On ampere-hour meter plants, when the hand is at FULL, the plant cannot be operated on account of the ignition circuit being broken.
In such cases allow load to be taken from the battery until the hand travels back sufficiently to allow the plant to run.
Occasionally the plant and battery are used to carry continuous loads of from 10 to 15 amperes each night, with practically no day load.
This condition necessitates running the plant to carry the load, but at the same time the battery is continually receiving from 10 to 15 amperes charge, with the result that the battery may receive too much charging. This would be indicated by the battery bubbling freely every time the plant is operated. To prevent this condition, the user should be instructed to carry the load off the battery frequently enough to prevent continual bubbling.
Where Small Load Is Used.
There are many installations where the battery capacity is sufficient to last several weeks. On installations of this kind it is advisable to charge the battery to FULL at least once a week.
The dealer or service man should use his own judgment on the preceding instructions as to which is best suited for the different conditions encountered.
Regularly on the first of each month, regardless of whether or not the battery has been used, a special charge, called the Equalizing Charge, should be given. This charge should be given as follows: The battery should be charged until EACH cell is bubbling freely from top to bottom on surface of the outside negative plates and then the charge should be continued for TWO MORE HOURS.
The monthly equalizing charge is a NECESSARY precautionary measure to insure that the user will bring each cell in the battery up to maximum gravity at least once a month. It also provides a means on the ampere-hour meter plants to set the ampere-hour meter hand at FULL when the battery is FULL.
The users should be cautioned to inform the service man or dealer immediately if any cell fails to bubble at the end of an equalizing charge, when all others are bubbling freely. This will enable the service man to inspect such cells for trouble and remedy same before the trouble becomes serious. (See further information under inspection and repairs.)
INSPECTION TRIPS
Undercharging or injurious sulphation is the most common trouble encountered. Undercharging causes the plates to blister and bulge, and in place of good gray edges on the negative plates and good brown color edges on the positive plates, the edges will show a faded color, with very little brown color showing on the edges of the positive plates.
Overcharging is not so evident on inspection, except that in such cases the active material from the positive plates, which is brown in color, will be thrown to the bottom as sediment more rapidly than the sediment would acc.u.mulate due to normal wear.
Heavy usage on a battery will also cause considerable sediment in the bottom of the cells, so that it is necessary to investigate carefully whether it is overcharging or overwork. A few questions as to method of operation and load requirements will aid in deciding the cause of excessive sediment. (See When and How to Charge, page 468.)
Sediment s.p.a.ce Filled.
When the s.p.a.ce below the plates is filled up with sediment and touching the plates, the cell becomes short-circuited and will deteriorate very rapidly. It will be noticed, however, that the sediment is heaped in the middle of the cell. If the cells are unbolted and unshaken, it will level the sediment and leave a s.p.a.ce between the sediment and plates. It is very important that the sediment be shaken down before the cell becomes short-circuited. This will very often prolong the life of the battery a number of months.
When the sediment s.p.a.ce is completely filled, approximately all the active material will be out of the positive plates.
A thorough study should be made as to the general condition of the battery and method of operation before forming an opinion or suggesting any change in method of operation.
Check Ampere-Hour Meters
On plants which have ampere-hour meters, the meter should be checked as to its speed on discharge, and also check position of the meter hand at the time of inspection, to see if it checks with the specific gravity and the pilot b.a.l.l.s. (See Ampere Hour Meter, page 467.)