I've been dumpster-diving my local recycle center, pulling out L91 lithium primary AA's and various NiMH cells. What I've been doing is using my multi-meter to measure voltage of the L91's. Some read as fresh at 1.8v, most are 1.6-1.7v. For the NiMH, I first see if I can get a reading for internal resistance using the Quick Test mode on the Opus. If the cell is completely dead, I'll pop it in the Xtar VC2 Plus Master for a few minutes to "revive a 0v cell", then I can usually get a IR reading. If it's 1500 or less on the IR test, I'll charge it at 200mA and re-test, then run a Test cycle to measure capacity. If it has decent capacity then I will run the Refresh cycle to see if I can regain some mAh. After Refresh, often the IR goes down dramatically as well (is this really possible, or is it due to flaky test nature of testing IR on the Opus?)
Anyways, is there any harm or value testing voltage and internal resistance of lithium primaries on the Opus BT C-3100 v2.2 charger? My understanding is it won't start charging for 6 seconds, which is plenty of time to catch a voltage reading. Also, I don't fully understand how the internal resistance testing works or if it even applies to a different chemistry like an L91, as the Opus is designed for li-ion and NiMH.
A less important question regarding internal resistance. I've read that a good IR reading is less than 100. I've tested brand new Eneloops and AmazonBasics NiMH right out of the box and get IR readings of 200-400. Rarely do I ever see a reading under 100. Is that normal for the Opus? Being such a budget analyzing charger I thought perhaps that the IR feature is not all that accurate. I couldn't quite justify the cost of the SkyRC MC3000! I have a few cells that consistently read out 1500-1700 on the IR test, is that high enough to warrant recycling them back to the recycle center? I had one Energizer AA NiMH cell I found today that read 7000 multiple times, which is definitely going back to recycle.
Anyways, is there any harm or value testing voltage and internal resistance of lithium primaries on the Opus BT C-3100 v2.2 charger? My understanding is it won't start charging for 6 seconds, which is plenty of time to catch a voltage reading. Also, I don't fully understand how the internal resistance testing works or if it even applies to a different chemistry like an L91, as the Opus is designed for li-ion and NiMH.
A less important question regarding internal resistance. I've read that a good IR reading is less than 100. I've tested brand new Eneloops and AmazonBasics NiMH right out of the box and get IR readings of 200-400. Rarely do I ever see a reading under 100. Is that normal for the Opus? Being such a budget analyzing charger I thought perhaps that the IR feature is not all that accurate. I couldn't quite justify the cost of the SkyRC MC3000! I have a few cells that consistently read out 1500-1700 on the IR test, is that high enough to warrant recycling them back to the recycle center? I had one Energizer AA NiMH cell I found today that read 7000 multiple times, which is definitely going back to recycle.