Temperature Correcting Battery Hydrometer

• Professional type
• Built-in thermometer for temperature correction
• Give accurate battery charge condition

To Prepare for Use:

• Carefully remove the rubber bulb and plug from the glass tube and remove the foam protector from around float.
• Wet and reinsert float, plug, and bulb.
• Extend rubber bulb on top of glass tube.

Instructions for Use:

Insert rubber tip into cell of battery. Hold instrument in vertical position. Squeeze bulb and draw enough liquid to float hydrometer freely, watching to see that top of float stem does not touch rubber stopper at the top of barrel.

The mark on the hydrometer float which is in line with the surface of the liquid indicates the uncorrected specific gravity. Add or subtract specific gravity points to float reading as indicated by the thermometer at the bottom. The result of the corrected float reading gives the precise specific gravity and indicates the condition of the battery.

Specific Gravity Reading:

Return liquid to same battery cell from which it is taken.

Cell Variation:

Variations of 20 or more specific gravity points between battery cells indicates a bad or weak battery.

NOTE: A proper test cannot be made unless each battery cell has sufficient electrolyte to permit hydrometer float to rise freely. An accurate reading cannot be obtained immediately after water has been added to cells or at below freezing temperatures. Water must be allowed to mix with electrolyte.

February 22, 2014

Verified Purchase

This one works. I had two others that gave inaccurate readings.

November 30, 2014

Verified Purchase

works very well. As advertised.

August 20, 2014

Verified Purchase

great for checking my deep cycle rv batteries, very accurate

March 17, 2014

Verified Purchase

This is a basic hydrometer for testing specific gravity of battery acid. The better the charge, the higher the float floats.

Colder water is denser and due to temperature caused density changes, one needs a correction graph to account for these density changes. This battery hydrometer does both, tells one the density of the battery acid being tested and includes a temperature correction gauge so one can add/subtract any temperature caused reading offset.

This is a basic unit, with, like a turkey baster, a vacuum based suction ball at the top so one can draw battery acid up into the glass tube, a float with numbers on it so one knows what the specific gravity of the battery acid is and a temperature correction gauge so one can correct for temperature caused density changes and at the bottom of the glass tube is a suction tube plug to be place into the battery cell where the battery acid is stored to be drawn up for testing purposes.

A suggestion, save the card the battery hydrometer is attached to because it has on the back, reminders of what to look for as to specific gravity readings which tell one how well the battery is charged.

That's it. This is an excellent piece of gear, at an excellent delivered price to have in one's automotive kit and I feel comfortable recommending this product. I gave it five stars as there's no reason to knock a star off the rating chart.

WARNING; be sure to thoroughly rinse this unit off before putting it away as left behind drips of battery acid can and will, if not rinsed off thoroughly, cause corrosion where ever it's laid down.

I hope the above helps in your buying decision.

January 1,2013 

Verified Purchase

I bought one of these many years ago loved it and recently my wife dropped and broke it. The new one is the same quality as the old and works great. It is hard to get out of the packaging and prepare for its first use though.