After 4.5 years of service my car battery seems to have died. On turning the key the starter clicks but it does not start. I jump started it yesterday. It worked fine. It won’t start today again so I checked the battery hygrometer. It is green. I checked the water level. It is full.
Battery’s will do that. Just tonight the wife called saying her 97 Accord wouldn’t start. I ran over to where she works and put the jump pack on the battery to start it. She drove it home and I just tested the battery with a battery load tester. It needs a new battery.
Why would you test the relative humidity?
I used a wrong term. The maintenance manual calls it color indicator - green, yellow and black. It does not use the term hygrometer.
I used wrong term. Hygrometer is wrong. The maintenance manual calls it color indicator. Green means good, yellow means charge it and black means change.
You don’t really have to guess about it. Jump it and take it to an auto parts store where they will test the battery and charging system for free. (Call ahead to be sure).
You used the right term. A hygrometer checks specific gravity. A hydrometer measures relative humidity.
You probably need a new battery. The hygrometer test only shows one possible cause of battery failure. Shorted plates will do it too. A load test will reveal the condition of your battery.
Don’t rely on those colored eyes. They’ve been known to be wrong.
I’d go so far as to say that they are plain useless - because they can easily be wrong. I suppose they’re probably more reliable in terms of saying a battery is no good. But they really don’t tell you a thing about whether its good or not. So whatever bit of $$ goes into adding them to batteries would be better not spent at all IMHO.
Nope, it’s the other way around. Hydrometer is for batteries.
OP, if you are talking about the built-in dot indicator, it’s only an approximation. Assuming you can take the tops off of each of the 6 cells, you can buy a hydrometer at the car parts store to test each of the cells. I bet you find one or more that are low. Likely time for a new battery, and check witha parts store to make sure the alternator’s OK.