Car Battery Tester 6V 12V 24V Battery Voltage Tester, BR502 100-2000 CCA 2Ah-220Ah Internal Resistance Tester Automotive Accurate Digital Auto Battery Analyzer for Car Truck Marine Motorcycle SUV Boat

Pros:- Inexpensive.- Cables remain flexible in Cold Temperatures.- Easy to Operate.- Intuitive Operation.- Gives a General Assessment of Battery HealthCons:- No Specifications of What Load is placed on the Battery being Tested.- Lowest CCA Setting is 100 Amps. To Large a Setting for most UPS Batteries.- Instrument Accuracy and Precision may not be the best.Physically, this battery tester is lightweight, portable, and has heavy duty enough battery cables and clamps that are flexible in weather down to 0 F. (coldest I tested). The digital readout is easy to see but does get a little slow and iffy at colder temperatures. Having only owned the tester for less than a week, I cannot speak to long term durability but I expect it will hold up to my needs if I store it in the original packaging that it came with. For the cost, I can afford to have a few as backups and in different tool boxes.I purchased this Battery Load tester to assess the health of a large number of AGM batteries from UPS Battery Backups. Those batteries are usually 12 volt, 9 AH batteries but with a range from 6 AH to 12 AH. A couple UPS's use 6 volt batteries in series. Most of the time, the UPS indicates the batteries are fully charged in the unit but the unit fails under a load when the supplied power is turned off. This indicates the battery is "bad" and I replace them (catastrophic failure scenario). I needed a way to assess when the batteries had not failed catastrophicly but did not have the minimum capacity I desired to make the Battery Backup worthwhile. I also needed to assess the battery health capacity after using a Smart Pulse Battery Charger repair function. Hence the battery tester.This Battery tester gives a measurement of battery voltage that is probably accurate within 3%-5% of the reading from my digital Multimeter. The reading is actually fairly reproducible so the precision is good. Voltage is not really a good measurement of battery health since a weak battery that is fully charged can give a voltage reading similar to one where the capacity is high.This battery tester also gives readings of resistance, Cold Cranking Amps (CCA), State of Charge (SOC), and State of Health (SOH). The latter two measurements are based off the value of the CCA that are user input. Battery resistance is a good indicator of a problem battery IF you have a good knowledge of how that particular battery type (SLA, AGM, Gel, Std. Wet Cell) operates and performs. For the 12 volt AGM batteries I regularly test and use, the resistance of a fully charged battery in good/excellent health runs 24 Ohms - 39 Ohms. Batteries that are sulfated, low on electrolyte/water will have a resistance reading greater than 100 Ohms. Failed cell batteries can have infinite resistance and will not operate the tester or take a charge.Cold Cranking Amp readings for the battery is the most important reading for the battery health. It is the measurement of the actual battery capacity left. The State of Health reading is simply a ratio of the actual measured CCA vs. the value of the battery CCA initially input. SOH can be inaccurate if the input CCA is different than the actual battery capacity. If the input CCA is inaccurate due to the actual new battery CCA being below the minimum level the Battery Tester will accept, the SOH reading will be off. SOC measurement on this tester is calculated from the measured voltage and CCA but does not take into account temperature.Still, this Battery Tester gives valuable information when comparing the measured values before and after battery repair charging and comparing to other batteries of the same type, voltage, and capacity.In conclusion, this battery tester does the job I purchased it for. It is inexpensive, light, accurate, and useful enough to have several in case of need. While it may not be the instrument of choice for electronic design engineers or technicians working on delicate precision instruments that require super high accuracy, this Battery Tester is definitely good enoung for the majority of people who need a assesment of whether the battery being tested is "good" or "bad". I recommend it for that.I could have given the tester 4-stars because the CCA range, at 100 CCA minimum, did not go low enough for my needs but, the range was clearly stated in the ad so I am using it knowing that it is not designed specificly for my application. It still works good enough for me.

Works as it should, great little tester and the price is good

the reason I did not give it the highest level is in the fact I just received it. I have only used it a few times. ( so far . very impressed ) seems to be well made.

It’s easy to use and good value plus no batteries needed, runs off tested battery.

Very easy to operate. Reads state of health (SOH) in %, eg, my battery was getting poor, and it read 53%. On three different tests, the cold cranking amps read a bit different each time, but definitely close enough for my discernment. I haven't compared this to a professional tester, but I would say it's good enough for a DIY, who just wants to know how soon the battery needs to be replaced. Or sometimes a low battery is not a problem with the battery, but something else in the charging system. This helps narrow that down. This can test a battery when it's charge is low.This may be identical to the Kingbolen, which looks the same, and has the same features, but is more expensive.

So glad I got these such a great buy in the delivery was right on time

Not clear on how to use

Does a basic job at testing your car battery