OTC 4619 Professional Battery Hydrometer , Red

I remember a day when these testers where super expensive. Now thanks to time and marketing they are so reasonable. If you do battery service on batteries that can be checked you need this tool. The specific gravity test is a much more accurate way of determining the condition of the battery. One thing to be mindful of. When you are done using it. Carefully take it apart and clean it. Over time the acid from the battery will dry it out and destroy it. This tool goes back to my youth in automotive service. It is well made and works very well.

great value, well made easy to read -- I think I will be quite happy with this tool. But it is fragile! I read every review here, noted the fragility so I made a nice little case for it from 2" PVC pipe but I still broke the thermometer when I went to disassemble it for cleaning the second time I used it.I think it comes apart easier than others reviews lead one to believe. A little careful rotation of the rubber parts on the glass breaks the rubber free and allow you to carefully slide it off for thorough cleaning. having read the float was quite fragile, I made sure it was laying horizontally and fully in the middle of the glass tube away from the rubber parts I was removing from the glass. but I wasn't thinking about the unsupported thermometer as I twisted that portion and I snapped the tiny tube. (yes I know mercury is dangerous, even the tiny bit in this tiny thermometer - I sealed the remainder with some hot glue because the little bulb of the thermometer penetrates the rubber tip so you have to leave the broken part to seal the hole from dripping electrolyte everywhere). Oh well, where my batteries are mounted, I don't have to deal with huge temperature changes and I can check my SG after the batteries have relaxed for a while on float charge....the SG scale is quite easy to read but I still made an enlarged version and attached it to my case so I can easily differentiate the numerical value of my actual readings. And be advised the specific gravity of electrolyte varies by battery manufacturer, I was a little surprised to see that my SG target value (what my marine batteries come with) was just a couple tiny marks into the green.

I ordered this to use on my golf cart, thinking it had to be better the the ones that I can get at the car parts stores. I especially liked that it was temperature compensated. When I took it out of the box I saw that the attached thermometer was broken. I immediately repackaged it and tried to have it exchanged on Amazon. They told me that it cannot be returned! What is the incentive for the manufacturer to make a quality product if they know that the customer is stuck with it, no matter how bad it is? With that being the case I decided to go ahead and use it, but quickly found out that the battery acid leaks out of the small hole where the bottom of the thermometer goes into it! Because of that I spilled several drops of battery acid onto the epoxy floor in my garage. Amazon and the manufacturer both suck for allowing such a piece of junk to be sold, knowing that it cannot be returned for being defective.

I'm familiar with hydrometers. This old-school tester incorporates a glass hydrometer bulb (shipped in a foam wrapping for protection, foam is to be removed BEFORE use). Carefully remove the lower rubber tip - do NOT break the tiny glass thermometer,nor the glass hydrometer bulb. The tool incorporates a small thermometer with scale to temperature-correct your readings for accuracy. The correction is either added to, or subtracted from, the hydrometer float reading, based upon temperature as indicated.This is a non-electronic, old-school analog tool. It does NOT need any batteries BUT you will need adequate illumination, and sufficient visual acuity to read both the hydrometer bulb scale, and the thermometer correction scale numbers - which are quite small.This instrument cannot be use in dark areas without a flashlight, a LED headset is best. If you need glasses for near vision, that also applies. Be aware the hydrometer bulb can rotate/spin inside the fulid tibe so you may have to rotate the tool to read the scale properly. This is just "the way it is" with floating hydrometers - welcome to the science laboratory.We can't comment on the durability of the rubber bulb and tip - (appear to be natural rubber) . We assume like most natural rubber products, the bulb and tip will eventually dry and crack, and possibly at some point in several years, may become unusable. We plan to keep it in a sealed bag, in a cool, dark, protected storage drawer, and possibly treat the exterior rubber surfaces with protectorant spray after rinsing off battery acid.Package labeling states. Made in Taiwan. Internet indicates OTC Tools address as OTC Tools, Bosch Automotive Service Solutions, 28635 Mound Road, Warren, MI 48092 USA.

My first OTC hydrometer lasted forty nine years. The rubber finally went bad. So I bought a new P/N 4619 hydrometer. It is just like the one I bought in 1974. I'm sure it will test perfect and last a long time.Thanks Mike

This is a very nice item. It's on the big side. I have a 51R Honda battery (For a CRV) and these batteries do not have a-lot of water covering the very top of the lead plates, inside this battery. So you may have trouble getting enough fluid into the hydrometer, to float the bulb, to get a good reading. This is not OTC's fault, or Honda's. It's just a way to get more power out of a smaller battery. Ok-I have not used this device at this time. When it arrived, I knew it was too big, and tried to return it. Amazon gave me a full refund, and I did not even have to return the item to them! WOW. I was very impressed by this! (So why is this wacko Trump guy so mad at Amazon??) Just kidding, but anyway, just make sure the batteries your using this on, have enough liquid on top of the battery, to float the bulb, to get a good repeatable reading. Or use one of Amazon's smaller battery hydrometers. Yes-even the ones with the little float balls will work. Just check the size of the battery hydrometer, before u buy it. My 2 cents.