1971 Evinrude 40HP outboards Service Manual, Page 67Get this manual
BA TTERY TES TS HYDROM TEST FLOAT MUST FREE ON LEV EL WITH LIQUID SUR MAKE CORR EC TION FOR TEMPE RATU RE
L OAD TEST DIS CHA RGE BA TTERY AT TE 200 MP FOR SEC VOLTAGE SHOULD NOT DROP LOW VOLTS (12 VO LT BA T