

⚡ Power up your diagnostics with precision and speed!
The OTC 3181 is a professional-grade 130-amp battery load tester designed for quick, accurate diagnostics of 6V and 12V batteries. Featuring ergonomic clamps for a secure grip, an oversized 0-16 volt display with zero adjust, and smart storage options, it delivers reliable results in just 10 seconds—perfect for managing multiple vehicle batteries and avoiding costly replacements.





| ASIN | B000O3U2UQ |
| Best Sellers Rank | #54,381 in Automotive ( See Top 100 in Automotive ) #71 in Battery Testers |
| Brand | OTC |
| Color | Black |
| Customer Reviews | 4.4 4.4 out of 5 stars (736) |
| Date First Available | July 7, 2004 |
| Global Trade Identification Number | 00731413417566 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 0.049 ounces |
| Item dimensions L x W x H | 9 x 11 x 4.2 inches |
| Item model number | 3181 |
| Manufacturer | Sunpro |
| Manufacturer Part Number | 3181 |
| Measurement Type | Ammeter |
| Min. Operating Voltage | 6 Volts (DC) |
| Model | OTC 130 Amp Heavy-Duty Battery Load Tester |
| Power Source | Battery Powered |
| Product Dimensions | 9 x 11 x 4.2 inches |
| Specification Met | CE, RoHS, UL |
| Style | Tool |
| UPC | 731413417566 |
T**G
works good
I have several 12 volt batteries at home. One good one that I use to jump start my lawn tractor when need be. A spare lawn tractor battery. and an old 12 volt battery with a hole in the case that allowed one cell to leak and dry up. I have all these batteries on a maintainer in my garage. So they all read over 13 volts with my meter. I have a quality Fluke multi-meter I used to first test the accuracy of the Battery load tester. The tester was right on, no need to try and zero the needle at all. I then load tested the known good battery and with the multi-meter also taking readings. Again the tester worked perfectly delivering a 130 amp load to the battery and reading an accurate voltage drop and a "good" result on the display for the battery. Waited for the tester to cool down. Can not test multiple batteries, or retest a battery too quickly or you will over heat the tester. My small tractor battery tested "good" with the load. I then tested the battery with the dry cell. I do keep this battery charged and with a multi-meter it reads and maintains 13 volts. This is the good part, under the load test the needle dropped to where the "known good" batteries did in the first several seconds, but as I counted off the 10 second test the needle dropped steadily to the "bad" range on the display. This to me was a perfect controlled experiment with an accurate result showing this Load Tester works perfectly. I feel that I can trust the results that it will give me in the future. I bought this because my power boat has 4 batteries. I noticed at the very end of last season I was having some issues with at least one of them. These batteries cost almost $200 to replace. I can now feel confident about testing each one of them and only replacing the one/ones that fail. This alone will more than pay for itself because I was prepared to replace them all just to be safe on the water. Will be testing them this weekend as I get my boat ready for the summer season.
A**R
Nice to have if you maintain several vehicles!
This is a nice and inexpensive test device. It also has better quality components than others I have used. The clamps and cables are really heavy duty. The handle is also a very nice addition over the other testers. This device seems to be well built and should last a long time. It will help you avoid replacing a non-defective battery or alternator by mistake. The tester is great for regularly checking the condition of jeep, car, atv, utv, truck, and tractor batteries. The easy to read dial will let you know if your battery needs replacing when you press the test button. In addition, the device serves as a voltmeter without pressing the button to check the battery voltage with the engine off and alternator voltage with the engine running. Just read and follow the simple directions, and you will be satisfied knowing the condition of your electrical charging system and battery.
S**R
Works great
Love it
T**N
Simple to use and read, great to check battery health yearly before the winter.
I use a Digital Multi Meter to check the DC voltage (typical 12.6 volts at rest before starting), because the readout is more accurate than the OTC test analog needle, but the OTC is close enough to get and idea where voltage is at. The true purpose of the load tester comes AFTER holding the test switch down for ten seconds. The internal resistor loads the battery at 130 amps, similar to a heavy start cycle. This test, at the ten second mark, you can clearly see if your battery is holding up under the strain. Green is good!! It's neat to see the resistor glow bright orange as it heats up!! Remember to let it cool down before storing it in the box. After testing, my battery reads 12.5 volts. But comes back to 12.6 in a minute. I bought mine for testing my camper batteries, but I also have used it many times for testing my car battery. Also lend it out to friends who need to determine if their battery is sulfated or just not up to snuff for the winter. So far my VARTA OE battery in the SUV is 7+ years old, counting the actual car build date (07/2012). Still kicks over easily,even last winter. Nothing wrong with the charging system or the battery. 90K + miles.
C**R
Good tester
The tester works well the analog voltage on mine is off about 1.3 volts. The unit will smoke during a load test. I would have no problem buying it again. If the voltage was perfect I would have give in 5 stars.
D**N
Nice unit, easy to use.
Easy to use, clamps are first class! As advertised!
D**T
Quick / easy battery load test
Great for a quick test on batteries
T**S
Durability and Accuracy
item is and works as described. Well constructed. Fast shipping and delivery.
M**L
Exelente producto
M**O
Does what it's supposed to do.
D**E
It checks the batteries as it should and I personally like the analog better than the digital.
J**E
Llego en tiempo y forma, se ve resistente. Falta probarlo
C**N
Exelente producto nuevamente otc Cumple con mis espectativas. Recomendable amigos mecanicos y electricos un producto durable y de buena calidad
Trustpilot
1 week ago
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