Temp. compensated hydrometer

[madlabs]

Hi All,

I bought a hydrometer with a thermometer. However, the thermometer is on the side of the unit, and essentially has no contact with the electolyte or even the tube. It seems that all this would do is tell me the ambient temp., not the battery temp. Is this how they usally are, or is this a crappy one?

Jonathan

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[dnix71]

http://www.rpc.com.au/products/batteries/car-deepcycle/carfaq4.htm

has detailed instructions on how to compensate for temperature. At 80F (27 C) there is no compensation.

Checking the state of charge on a battery is best done after it has rested from being charged, so the battery should be the same temp as the room by then. If you are a purist, you could dip the thermometer into a middle cell for a reading. If it's a glass thermometer it shouldn't do it any harm.

[madlabs]

Dinx,

Thanks for the link, that is a very complete "how to" for the hydrometer. While I'm not a purist, I think I'll pick up one of the temp. compenstated hydrometers showm on that site.

Jonathan

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