The answer to JK’s question on “failing generator batteries” in June 1997 needs additional information. First, you need to find out why the engine-driven charging system is not working. Usually, there is a voltage regulator to hold constant voltage, so the charging current will taper off as the battery comes up to full charge—about 27½V, depending on the age of the battery. Second, and probably more important, you should adjust the standby charging rate to ½A to 1A—usually 370mA or so. (The actual rate will depend on the age and condition of the battery). You should adjust the rate to keep the specific gravity to 1.220 or 1.280, depending on the original electrolyte while not boiling out all the water. If too much water is used, lower the trickle rate. If battery loses charge, raise the rate.

I presume the question about “cement” refers to concrete. The “sitting” on concrete does not discharge batteries any faster. They slowly discharge themselves. You must keep the battery tops clean and dry. —R.M.S.



It seems the respondent to J.K.’s question in the June 1997 issue isn’t familiar with his equipment—300 hp rather than a kW value. He also assumes the positive battery ground is correct, and the “no engine generator output” refers to the battery charging alternator on the engine. This may be a completely wrong assumption.

J.K. should call the manufacturer’s local distributor of the generator set or a qualified service company. I have an uneasy feeling this important piece of emergency equipment is still sitting with dead batteries (and perhaps more serious problems). —P.L.D.