Internal battery resistance was one reason Ohm's law was not immediately adopted. Simply adding batteries in series did not proportionately increase the current capacity so E=IR didn't work out. It wasn't until thermocouples were used (extremely low internal resistance) that what we think is obvious was accepted. So, see? Internal resistance can be important. 😁
@@simontay4851 I said current capacity, not current. If you have a perfect 1-volt battery with a 1 ohm load you would have 1 amp of current. If you then added a second 1-volt perfect battery in series with the first battery the voltage would double to 2 volts and the current, through the same load, would increase to 2 amps. The early batteries were far from perfect. Change those perfect batteries to ones with a 1 ohm internal resistance, which is modeled as a series resistor. With one battery you would have a total resistance of 2 ohms (battery and load) with a current of 1/2 amp. With two batteries in series, you end up with 3 ohms total series resistance and the current would be 2/3 amp. If you ignore the internal resistances, which the early experimenters did since they didn't know it existed, you'll see that Ohm's law doesn't seem to work. When they doubled the voltage by adding an additional battery the current didn't double as expected.
I think five ohms or lower is best for auto batteries. For my off grid 180kWh battery, less than 25mOhm per cell is best. 5mOhm or less for automotive battery.
@@USA-GreedyMenOfNoIntegrity No, no, no, no. no. 5 ohms is horrendous. Tested resistance of old and Failed AGM batteries were in the vicinity of 40 milliohms. Fresh good batteries were in the 9-10 milliohm range.
@@1shARyn3 I was just seeing this meter and thinking of my Boat battery bank, 8 wet cell batteries tied together in series 13,7 at the inverter, without separating them have just the old Hydrometer method to test the cells
If you use rechargable li-ion or li-po or even lifep04, the internal resistance is how you measure the health of a cell. When new, the resistance will be very low, like 1-5 ohms, and when kaput, they will be much higher. Any quality lithium charger will have ir measurement included, but i think a dedicated meter might be handy. I think I'll order one.
The range of ohms shown seems suspect to me. During testing to figure out battery for alkaline (AA, C, and D cells), a 1 ohm internal resistance meant the cell was (almost) dead. The resistance was below 200 milli ohm for most of the batteries life. The 9V batteries have higher resistance b/c the cells are tiny to fit 6 cells in the package, so a 100 ohm max would make sense (100 mA max current). The lithium cells (when charged) have really low internal resistance - enough for accidental spark welding if your careless.
Made the simple one, using a cheap DVM module, and a rather heavy resistor made from an old toaster element. Use it to check 12V SLA batteries, to find those that are near dead. The other chunky one is for car batteries. This one looks like it will do a lot more testing for me.
@@IMSAIGuythat was fun to watch! Now imagine instead of alligator clips I have pens with two sharp pogo pins already mounted. Perfect for flat top cells. I just need to terminate them to the HRM-10. Need to know what the connector model number is. I can do my own fumble on the wires, lol.
Like it... In my oppinion it is most interesting for all kind of rechargeable cells. Just knowing the resistance of a fresh cell and comparing it to the actual cell (same size at lest) you can tell within a second if it is good, kind of okay or even ready for recycling... In the moment im am using my capacitor ESR Meter, it is also okay for batterys with not to much voltage... But having ESR and Voltage side by side is nice...
I would say these units are good for testing UPS battery packs. Rather than running an hours long test at an appropriate load you could check the pack for high internal resistance. In my experience on smaller UPS of 500 -1000W, 100 mOhm or less is good for a 48V pack. An internal resistance reading of 1 Ohm or higher is not good.
Very interesting. My question is, what values would be considered good or bad. I initially had the same questions when measuring capacitor ESR. After some research it was found that the answer depends.
But OF COURSE you would want to push the buttons on the meter - can't you see that it can increase the voltage and decrease the resistance of the battery...? That alone is worth every penny...!
Internal battery resistance was one reason Ohm's law was not immediately adopted. Simply adding batteries in series did not proportionately increase the current capacity so E=IR didn't work out. It wasn't until thermocouples were used (extremely low internal resistance) that what we think is obvious was accepted. So, see? Internal resistance can be important. 😁
Batteries in *parallel* increase the current, series increases voltage.
@@simontay4851 I said current capacity, not current.
If you have a perfect 1-volt battery with a 1 ohm load you would have 1 amp of current. If you then added a second 1-volt perfect battery in series with the first battery the voltage would double to 2 volts and the current, through the same load, would increase to 2 amps.
The early batteries were far from perfect. Change those perfect batteries to ones with a 1 ohm internal resistance, which is modeled as a series resistor. With one battery you would have a total resistance of 2 ohms (battery and load) with a current of 1/2 amp. With two batteries in series, you end up with 3 ohms total series resistance and the current would be 2/3 amp. If you ignore the internal resistances, which the early experimenters did since they didn't know it existed, you'll see that Ohm's law doesn't seem to work. When they doubled the voltage by adding an additional battery the current didn't double as expected.
Way cool! Thanks for the review! I think I want one.
It may be interesting to dig into the relation of the battery resistance and battery life span
Nice, neat, does what it says on the tin but not sure when I would need one!
Was waiting for a test on a car battery
I think five ohms or lower is best for auto batteries. For my off grid 180kWh battery, less than 25mOhm per cell is best. 5mOhm or less for automotive battery.
@@USA-GreedyMenOfNoIntegrity No, no, no, no. no. 5 ohms is horrendous. Tested resistance of old and Failed AGM batteries were in the vicinity of 40 milliohms. Fresh good batteries were in the 9-10 milliohm range.
@@1shARyn3 I was just seeing this meter and thinking of my Boat battery bank, 8 wet cell batteries tied together in series 13,7 at the inverter, without separating them have just the old Hydrometer method to test the cells
Don't you hate it when the unit is so light that the big chunky cable pulls it around?
If you use rechargable li-ion or li-po or even lifep04, the internal resistance is how you measure the health of a cell. When new, the resistance will be very low, like 1-5 ohms, and when kaput, they will be much higher. Any quality lithium charger will have ir measurement included, but i think a dedicated meter might be handy. I think I'll order one.
The range of ohms shown seems suspect to me. During testing to figure out battery for alkaline (AA, C, and D cells), a 1 ohm internal resistance meant the cell was (almost) dead. The resistance was below 200 milli ohm for most of the batteries life. The 9V batteries have higher resistance b/c the cells are tiny to fit 6 cells in the package, so a 100 ohm max would make sense (100 mA max current). The lithium cells (when charged) have really low internal resistance - enough for accidental spark welding if your careless.
Made the simple one, using a cheap DVM module, and a rather heavy resistor made from an old toaster element. Use it to check 12V SLA batteries, to find those that are near dead. The other chunky one is for car batteries. This one looks like it will do a lot more testing for me.
Can you check, is this a GX12-4 aviation connector? I'd like to make a Kelvin cable using dual-prong pens and need to know what to buy.
ruclips.net/video/w9hvT0428jc/видео.htmlsi=GB-8Eer0p2EkeRBI
@@IMSAIGuythat was fun to watch! Now imagine instead of alligator clips I have pens with two sharp pogo pins already mounted. Perfect for flat top cells. I just need to terminate them to the HRM-10. Need to know what the connector model number is. I can do my own fumble on the wires, lol.
Thumbs up, looks like a good meter, just have to find specs on the different batteries, agreed it looks like a hook it up, and it does its thing
Like it... In my oppinion it is most interesting for all kind of rechargeable cells. Just knowing the resistance of a fresh cell and comparing it to the actual cell (same size at lest) you can tell within a second if it is good, kind of okay or even ready for recycling... In the moment im am using my capacitor ESR Meter, it is also okay for batterys with not to much voltage... But having ESR and Voltage side by side is nice...
Cell internal resistance is strongly correlated to how much charge is left, they need to be the same voltage for it to make sense
I would say these units are good for testing UPS battery packs. Rather than running an hours long test at an appropriate load you could check the pack for high internal resistance.
In my experience on smaller UPS of 500 -1000W, 100 mOhm or less is good for a 48V pack. An internal resistance reading of 1 Ohm or higher is not good.
Uses for a micro ohmeter...
I wonder how it would react when capacitor or inductor were connected? What processing is done on the measured ac signal?
Banggood were supposed to be sending me one of these to review, hasn't shown up so I think it fell through, pity.
Very interesting. My question is, what values would be considered good or bad. I initially had the same questions when measuring capacitor ESR. After some research it was found that the answer depends.
With capacitor ESR, the lower the better.
You'd use it for trends on a single battery or to compare batteries in a fleet. A single reading of a random battery isn't much use
@@simontay4851 "The lower the better" tells you nothing.
it could be used to check the ESR of electrolytic capacitors too.
Seems like it could have been a simple ESR tester as well with those four wires... does it do double duty as a milliohms tester?
I have used a different brand meter (also 4 wire) for this to test contact resistance loss or shunt resistors
But OF COURSE you would want to push the buttons on the meter - can't you see that it can increase the voltage and decrease the resistance of the battery...? That alone is worth every penny...!
No cat? Cat lovers found new tricks with this one.
This unit needs more work. It would be far more useful as a battery tested if it included a PC-editable menu of generic battery types.