Review on E Z Red SP101 Battery Hydrometer by Michael Gutierrez

I once had a hydrometer with floating balls. That's pretty much useless. I threw it away and relied on the voltage chart to see how well the battery was charged. I recently bought a float hydrometer to check if a cell in my five year old battery had failed. The cells were fine, but this showed me how charging with the smart charger temporarily causes the hydrometer to go low. During charging, water forms which rises and dilutes the electrolyte at the top, where it is sampled by an areometer. A conventional charger creates bubbles that help stir the electrolyte. I prefer the smart charger because bubbles age the battery. There was a line for every five thousandths on the hydrometer, but they were only 1mm apart and I had to count them because the numbers were usually on the other side of the float. When I discovered the float was leaking, I replaced it with an EZ Red. I tested it with a saturated saline solution that is very close to 1,200. So said EZ Red. An accurate reading may require interpolation as EZ Red has fewer notches. I prefer that to the account. Below 1.225 (about 75% loaded) the scale is as small as my float hydrometer. It's twice as big at the top. I like it. I need accurate readings above 1.225 to ensure all cells are fully and evenly charged. When I was done, I placed a plastic bowl next to the battery to hold my float hydrometer so I didn't drip onto the car or my clothes. The smaller capacity is enough to test the EZ Red. On battery power it showed up a few times due to the bubble. A few times it went down because I wasn't getting enough electrolyte. (It only takes a tablespoon for this.) It ran out at one point because it wasn't quite even. All in all, it's pretty reliable. When the IR thermometer showed my battery was 60F below the waterline, the voltage showed it was fully charged, but the SG reading was only 1.265. The same happened after a night's rest. I thought I had delamination until I remembered that EZ Red is temperature compensated. The standard battery temperature is 80 F at which the 1.265 is fully charged. Because the electrolyte doesn't mix well in cold weather, winter segregation can be a problem. This will prevent the battery from being fully charged and the battery will quickly fail if not fully charged from time to time. At the national level, stratification is a significant factor in battery failures. EZ Red lets me test the bundle. If I can find one, I can charge the battery on a warm day, bring it in and put it in a pot of warm water, or buy a heating pad to put under the battery.