Harbor Freight Cen-Tech Battery Load Tester and why you need one! 

Kansas City Auto Electric here, Great video. I use this tester all of the time. I love the idea that it is old school and does not cost close to 1k like some of those digital ones do. The only thing I would like to add is when checking your charging system when using this load tester DO NOT use the toggle switch on the bottom. If you do you will short out the charging system. It is read-only. I know it should be obvious but I have seen so many people that do it and wonder why their car no longer runs.

Before using the device, make sure it is reading zero, before connecting to battery. The device is fairly accurate, but only if it starts at zero. If it is not at zero, all of your measurements are worthless. Don't assume that it is zeroed out. If it is not at zero, use a flat screwdriver to adjust the almost-invisible screw head at the base of the needle so the needle is precisely on zero before testing. Also, the newer versions of the Cen-Tech load tester have upgraded the aircraft toggle to a low-profile switch just like the competing devices. Good improvement, in my opinion.

Who needs a digital $100 plus battery tester when this analog on does it all. This video explains it all quite thoroughly. Great presentation.

Thank you so much. You're the 1st one I've been able to learn anything from watching RU-vid. I plan to follow from here on out.

Extremely well done Jason. Wish I saw it BEFORE I shelled out $50 to Pep Boys! I think it is the same tester, BUT, Now I know how to use it. VERY helpful. Beats lugging in the battery every time to get tested.

Figured I should buy one of these load testers after jump starting my MIL's car. Covid has a lot of people not running their cars as much. Thanks for the tutorial.

Thanks for sharing, just a couple othe things you didn’t mention, when your testing the alternator with the load tester and engine running turn on all excessories, bright lights, ac, wipers etc this will produce extra load to see how your alternator is sending juice to the battery

This is a great video! You explained how it works, and precautions in a simple manner.

Out of the 633 of us.............I bet 80% of your subscribers OWN one of these now😳❤️❤️❤️❤️❤️

Excellent video! I bought one from HF years ago and never needed to use it until today, then I realized I didn’t have ay instructions on how to use it, until I found your video! Thanks it works like a charm-my battery was toast.

Best! Battery Tester Video I've seen...💦..Big Thank You, to Jason

Thank You for this video , it was amazing, getting round to it , no excessive talking . Very instructive. I give it 2 thumbs up and a “Like”.

Thank you for taking the time to show an dyi how to use this device. Now that i know how to use this. I will definately be buying 1 of these.

Jason thank you for the awesome video. I learned what I needed to learn from you. Thank You Again for taking the time to educate us and making our time to get things done more valuable!

Thank you very much for your video, I learned a lot how to test battery and I’m already bought one of these load tester, keep making an educational videos.

Excellent video. Just bought one and with your help I now know how to use it. THANKS

Your video instruction is one of the best on RU-vid, buddy! Followed you for more! Thanks for sharing

Great job. I just bought this tester today and needed this video. Thanks.

Thanks for the video. I recently bought one of these that's Buffalo Tools branded (probably made in the same factory, it looks exactly the same as the Cen-Tech). The manual it came with was not very good. Your video cleared up a lot of stuff on how to use it.

I can't believe I was unaware of these load testers. I started thinking about the need for such a thing this AM glad there is such a cheap product option out there. For a hobbyist the Cen-Tech is probably just fine!

Nice video and explanation and demonstration of a manual car battery load tester! I never knew there was a heating element inside the load tester that was used to draw the load from the car battery! Very inexpensive way to test a battery just before winter! Most car batteries will last 5~6 years at best and a car battery load test is a very inexpensive and low tech tool that everyone who owns a car should have in their DIY tool box.

Great tool to have.Many batteries may hold voltage but they lost amperage and there is no way to know just by voltmeter, especially AGM and sealed batteries where you can't measure the acid...I bought load tester for my solar battery bank, now I know if any of my batteries going bad, because if in series it takes only one bad battery to take down whole string...

This was exactly what I needed to know. I wanted to know if I could test a battery when it was not installed in a vehicle. This was a GREAT video and it explained everything so clearly. Even a dummy like me could follow it 😁😉

Had one of those devices for 3 years and just realized I was using it wrong. Thanks so much! I feel like a fool. I have a bad habit of not reading directions.

Thank you for a step by step, easy to understand video.

Thanks for the information. My main cranking battery on my boat reads 12.6 and it will not start the engine. I can jump it with the trolling motor batteries but there's clearly a problem. Now I can check to see if that's the problem. Great video and I subscribed!!!

Excellent video! Clear and helpful instructions. Thank you.

Very Good, simple and thorough and to the point.

Great video. I got a few batteries sitting around to test.

Hes very pleasant. Its easy to understand!! He addresses all imp issues!!!

Great easy to understand video,you didnt talk about the lower (yellow) scale regarding crank voltage.

Excellent video Mr Jason, Very didactic, even though you are not a Harbor Freight Tools salesman, I manage to motivate myself to buy one. Thank you very much for uploading the video, I am your new subscriber, Have a good day.

Fantastic video! I just picked one up today on sale reg $35.00 on for $14.00 🙂

You covered all the bases excellent tutorial.

Thank you for the description. I have one of these and clearly missed some of the details you pointed out. This video helped me out greatly.

Very clear description and demonstration.

Thanks for a great video Jason. Surely will helps me.

Good, simple and clear instructions. Thanks.

thanks for the very thorough well explained video on how to use this

Jason thank you for a good video, i bought one at harbor freight I think it will come in handy. I have a riding lawnmower, atv, and two cars. Thank you 👍

Thank you brother for another great video. I got learned a lot. Thanks again and GOD BLESS. Mike

I use this for a load test. To analyze the battery CCA and resistance I use the yellow cen-tech digital battery analyzer

Thank you for posting. This was very helpful.

I've used this tester for over 35 years, still works! (Its a Chicago Electric and the load resistor is 50amps DC) MAKE SURE TERMINALS AND CABLE ENDS ARE CLEAN AND TIGHT! Just because it looks good that isnt enough. Connect it once and do these steps in this order. 1. Test battery standing voltage 2. Load test battery 3. Starters cranking draw (a defective starter will have a higher load simulating a weak/bad battery) 4. Alternator output Also, batteries are often "up" labeled on capacity ratings so a battery rated for 900 cca may only test at 800+ when new.

Very timely and informative

Thank you I just bought one I didn’t understand how to use the seller done bad job in explaining But the video was an excellent

Best explanation so far. Thanks

Nice, informative and to the point. Keep it up. Cheers.

Cool. I just bought one yesterday at Harbor Freight.

Great simple and clear explanation....thank you

Great video. Buying one today!

Thank you that was excellent info...

Some people will argue that it only puts a 100 amp load. Most batteries can be well over 550 CCA. They say the tester should test half the CCA of the battery. Well, the load testers' instructions say to test for 10 seconds and let cool for 1 min. The test cycle is 3 tests in 5 min. I've been using these for years at a professional shop. Electronic testers work well but you have to know CCA and/or amps. If the stickers are gone you can't know this. The load tester doesn't need this and it is much faster. Also, an electronic load tester may say good recharge whereas a load tester will say weak. When viewed In an escalating 0 to ok scale. The bar graph on the electronic will show the amps closer to zero but will say the battery is good. Vs the load tester just tells you it's weak. If we were to only see the graph itself without the outcome most all of us would say replace the battery and that's the difference between being stranded or not. Load testers for the win IMO.

Read the instructions, what? I'm too smart for that! Cost me hours of cleaning connections, installing a new starter and massive embarrassment when the battery turned out to actually be the culprit. I had been told that, "Advance Auto Parts checked the battery and found it "Good"". I double checked that finding with my trusty Harbor Freight Load Tester, and confirmed their result more than once. Been many years since I last used it, and apparently forgot the procedure you outlined... To my detriment! I just checked that same battery again, with the same meter, and it's VERY obviously bad. Who knows, maybe I'll learn from this.

Great Video Jason

Thanks, you did a great job

Thanks so much the information was so handy and useful!!!💯💯💯😀😃

Thank you for the lesson very good

Great explanation! Thank you.

Absolute killer video❤️ You explained everything perfectly👍🏽 So that even “POLITICIANS” or “LAWYERS” WILL UNDERSTAND! HARBOR FREIGHT should pay you a $1 Commission for everyone that you sell! Because that’s where I’m going now❤️😡

Great video for the novice. Thank you

thanks so much for explaining things. i am refurbinshing my 1st battery and bought this today. going to come in handy after these 5 rounds of 15 minutes on the 200 amp.thanks a lot

Great video, I was looking for 2 minutes or less, but watched at a higher speed, well worth my time. :)

Excellent Tutorial...Thank You.

Thanks for info on Cen-Tech (buying today) but Just fyi....these batteries that charged over night and are still weak, need to be left on for a few more days. I just recently learned this after having discarded some batteries too early. I have 6 batteries in my barn right now going thru this multi-day charging because of our cold snap...its a long process, but may avoid wasting money.

Great video I got one of them and I love it

Great video. Living on a farm I have over 20 different pieces of equipment that take batteries. From tractors to generators to cars, trucks, motorcycles, mowers and snowblower I'm always replacing batteries in something. Don't know why I never bought a load tester but on my next trip to town I'll be stopping at Harbor Freight for one.

Super helpful video Thank You !!

Thank you for the video

Great video. Thank you so much!

Very informative video! Thanks!

Thanks for sharing this with us, and God bless you!

True, Voltage means NOTHING on a battery. The capacity is more important. Many bad batteries will show 12V but not have enough current to run the load. Just like a starter, just because you see it shoot out and spin free does NOT mean its working. When people test a starter, they test it with a zero load. The true test is a loaded starter test

Nicely done. Thank you.

It would've been good if you showed how to use this load tester to Load Test both the Charging System and the Starter. Cheers

Awesome video. Real teacher!

Good job I would add that, You need to take the readings and calculate the internal resistance of the battery. That is the parameter that really matters..

Thanks for you video, It is very helpful to me.

Great video. Thanks for sharing it.

Scored one at Walmart clearance isle less thank HF....thanks for the vid

Good video. FYI - Marine Cranking Amps are measured at 32 degrees F, Cold Cranking Amps(CCA) are measured at 0 degrees. A 1000 MCA rated battery is roughly equivalent to 800 CCA

Great information. Thank you

Muy bien explicado. Sos un capo.

You can do all of this with just a cheap but accurate voltage multimeter, tripod with cellphone video recording on the meter display, and a screenshot of this battery load tester for reference; using the car starter as load and you can record the initial voltage of battery, the voltage drop when starting, and the charging voltage when car is started.

Great and helpful video thanks

Amazing video way better than the owners manual

Thank you, great video

great video. what you stated at the beginning of the video was exactly what happened to me. lol

Great video! Thank you.

Really good video thanks

Very helpful, thanks. 😊

Great video !

Excellent video.

Wonderful detail, appreciated closeups. What else have you tested?

Well explained thank you

Going to get one tomorrow

🎉 what a Great video! thank you!

Did you charge the battery all the way up first? I might have missed you saying that. For me, it makes a big difference. good video

EXCELLENT EXPLANATION !

Very informative .. Ty