FNIRSI HRM-10 Precision Voltage Internal Resistance Battery Tester

I've owned this tool for a couple of months, and it has proven itself many times. ----- BEFORE YOU BUY ONE, read this: This particular listing is just the tool and a set of Kelvin clips, which are fine for batteries with tabs or posts, but are a pain to use for any cylindrical cell. They make a cylindrical cell holder accessory for the HRM-10, but the only way to get one (as of July 2025) is to order directly from FNIRSI from China. Luckily, it seems they listed another version of the same tool , but it includes the cylindrical battery holder AND a set of Kelvin-style probes. Trust me, it's well worth paying more to get the complete kit with those accessories. I wish they had this option when I bought my HRM-10! ----- Okay, now the review: Using a multimeter to check a battery serves most people well enough; if it shows somewhere near the expected voltage, it's most likely a good battery. But voltage is only half the story -- if the battery has a high internal resistance, it won't perform well in high-power devices (if it even works at all) nor last very long, and in the case of a rechargeable battery, it won't recharge fully (or the battery charger might not "see" it). That's where having a tool like this comes in handy. As for my use, I have a large pile of unprotected 18650 and 21700 cells, and ever so often I'll find one of them dead. I have a "smart" charger for these batteries, and sometimes it acts like I didn't just insert a battery. When I put that battery in the HRM-10 and see that its internal resistance is several ohms, then I know why the charger can't "see" it, and I can discard the battery without any doubts about whether it was a savable battery with a false reading. Over the past few years, I've picked up a FNIRSI tool here and there, and now that I own about three of their tools, I've got to say that I am supremely impressed with their design, functionality, material and build quality, and craftsmanship. The HRM-10 is no exception -- it feels great in your hand, and there's nothing cheap about it. If you're an electronics hobbyist who works with batteries, this is an invaluable tool. But make sure you get the one that includes the battery holder !

Great unit works well and easy to understand. We use it to check out solar batteries at many cell towers.

The meter works really well, but I highly recommend purchasing the pogo pin tips depending on what you are measuring. Strangely, the meter would sometimes get the measurements completely wrong and would require a restart. It would show >100v on a 4v cell for some reason.

Excellent tool for checking and matching lithium-ion batteries and any voltage-measuring tasks. Works great and I like the rechargeable aspect.

Awkward to use as designed. Inconsistent IR readings due to poor contacts. Poor instructions. They do a great job at marketing thought! Sent it back. I will try an Ancel that Project Farm reviewed. It is real hard to find a IR tester that does deep cycle battery's with an Ah vs CCA input.

Very good device

What a (battery) life saver. Tested 4 batteries and IR was between 3.3 and 3.7 mOhms. Charged and balanced the batteries and retested. Volts ranged from 13.34 to 13.6v. and IR was between 3.35 and 3.45 mOhms for 3 batteries. The 4th battery - had an IR or 221 Ohms - clearly a bad sign of immanent failure and potential damage to the other batteries in my system. I will be returning it. The tester "volts" is accurate compared to my other testers. Better than the BlueTooth BMS for another battery which was off by 0.20 volts and I could adjust (calibrate) the BMS of that battery. First use, I accidently started off with getting the Chinese language set. To get out of this quandary: Press the right arrow (settings) and select option 8 and arrow to select the English language.

Yes, it seems to be an extremely accurate meter very happy with it. I really don’t have anything to compare it to, but it seems to be a spot on when I compare it to reference references I do have.

FNIRSI se ha estado volando la barda con los últimos dispositivos que está sacando. Este es uno de ellos. Excelente e inclusive tiene un modo sorteo por si lo usas en algún entorno de producción. Es muy preciso, y lo puedes ver también en los diferentes reviews y reseñas que hay en internet. Al ser un medidor en Kelvin es muy conveniente. Lo uso para mediciones de resistencia y para comprobación de resistencia interna de baterías. Sin detalle, recomendado.

Good

Value for money

Excellent device! Only problem is that the clamps at the end of the wires wouldn't access the battery terminals of my machine while the batteries are placed in their slot of the machine

nice product