Voltage level when devices that take two AAA batteries start to fail? - Page 1
Forum section: electronics / beginners

author: eeguy
author_rank: Regular Contributor
timestamp: July 03, 2023, 07:18:57 pm
content: Hi, is it normal that for devices such as computer mouse to stop working once both AAA batteries have dropped to 1.1V each?

author: Gyro
author_rank: Super Contributor
timestamp: July 03, 2023, 07:29:40 pm
content: Not ideal, for full capacity utilisation, alkaline battery endpoint voltage is around 0.8V, but very common with electronic stuff these days. Actually with the lousy leakage performance of alkaline cells these days, getting them out of there as early in their life as possible probably isn't a bad idea!

author: eeguy
author_rank: Regular Contributor
timestamp: July 03, 2023, 07:32:46 pm
content: My mouse seems to be dead. The LED in it is off. I took out the two AAA batteries and measured the voltage. They both had about 1.1V each. Then, I found two AAA batteries in a drawer. I measured the voltage and they both had about 1.1V. Probably I took them out from a TV remote controller when it failed to work. They are all Duracell. Is there a better brand?

author: CountChocula
author_rank: Unknown
timestamp: July 03, 2023, 07:35:45 pm
content: It depends on the batteries and the device, but, probably… yesTake a look atthis datasheetfrom Duracell: You can see in the discharge curves that, once you're around 1.1V, the battery is pretty much depleted (as Gyro notes, full depletion is usually around 0.8V, but after 1.1V, the voltage decreases very rapidly, and you're measuring the voltage without any load attached—under load, it will likely be lower). Now, your batteries may behave differently depending on brand and chemistry, but in general I would say that your mouse is acting about normal.

author: Xena E
author_rank: Frequent Contributor
timestamp: July 03, 2023, 07:38:58 pm
content: Quite probable that the device had draged the cells lower than 1.1 volts but they recovered to that before you checked them. A lot of devices make lousy use of the capacity in the cells that power them though.

author: Gyro
author_rank: Super Contributor
timestamp: July 03, 2023, 07:43:00 pm
content: QuoteBetter or worse is unanswerable. They are a 'premium' brand, like energizer, but they both have a bad reputation for leaking and ruining euipment ( just do forum searches for the two and thinks like alkaline hell). Supermarket own brands may be better or worse in this respect. Energiser Ultimate Lithium don't seem to leak, but are expensive and have a starting cell voltage around 1.8-1.9V, which may or may not cause a problem.Your best bet is to go with low self-discharge NiMh, and recharge them (accept that you will have to do this more often. At least you're being environmentally friendly then, and the chances of turning your mouse into a corroded mess will be much reduced.

author: bdunham7
author_rank: Super Contributor
timestamp: July 03, 2023, 07:47:05 pm
content: Quote from: eeguy on July 03, 2023, 07:32:46 pmWhat exactly did you measure them with? If you used a regular digital multimeter, you would need to test again with a load. There was a recent discussion where someone measured 1.38V open circuit with a very dead AA cell. That surprises me a bit, but I don't usually test AA cells other than with a dedicated tester, so I've no data on the OCV of dead alkaline cells.QuoteThe question should be "is there a worse brand".For AA/AAA size applications, Energizer Lithium Ultimate cells are expensive but are the longest lasting in things like mice and remotes. As a bonus they don't leak. For higher-drain applications where you have to replace them once in a while anyway, NiMH rechargeables are the way to go--Eneloop seems to be the best AFAIK. There are a few devices out there that won't work properly with one or the other of these, for those you need to keep on suffering with alkalines, or in certain instances you could try the Batteroo.https://www.batteroo.com/products/aaa-sleeve-15/

author: Gyro
author_rank: Super Contributor
timestamp: July 03, 2023, 08:27:22 pm
content: On the subject of premature drop-out, some devices are far worse. Blink cameras willonlywork with Energizer Lithiums. I've had a couple of cameras drop out now (original batteries) without any pre-warning. In both cases, the batteries read 1.5V open circuit but new batteries fixed the problem. I've found that they work just fine in low drain applications, clocks etc. A leak free second life.

author: wraper
author_rank: Unknown
timestamp: July 03, 2023, 08:35:49 pm
content: You need to remember that 1.1V is under no load and when alkaline battery discharged this much it has very high ESR on top of low voltage. Shutting down at 1.0V it the best you can expect from such devices.

author: schmitt trigger
author_rank: Super Contributor
timestamp: July 03, 2023, 08:48:50 pm
content: I have had similar experience with a Logitech wireless mouse. It uses a pair of AA cells, in parallel. That tells me it draws significant amount of current. And by the same token, the batteries drop out while still reading healthy, open circuit.But the battery contacts are very flimsy, one can tell that the batteries are not being held tightly.

author: radiolistener
author_rank: Super Contributor
timestamp: July 03, 2023, 08:49:15 pm
content: Quote from: eeguy on July 03, 2023, 07:18:57 pmThis is a good cut-off voltage. Because Ni-MH rechargeable battery discharge should be stopped at about 1.0–1.1 V/cell, if you discharge it below that it leads to a battery permanent damage and capacity lose.

author: TimFox
author_rank: Super Contributor
timestamp: July 03, 2023, 09:19:56 pm
content: I believe that the internal series resistance of alkaline cells starts increasing before there is a noticeable drop in open-circuit (no-load) voltage.However, this curve is not normally shown in battery-maker specifications, instead they show the terminal voltage vs. time and load (current or load resistor).

author: RJSV
author_rank: Super Contributor
timestamp: July 03, 2023, 09:30:53 pm
content: Using 'variety' store LED lights, the little processor gets fed with 2.3 volts, on THREE regular nickel metal rechargeables, (when drained down). Don't know if it still runs, but likely does because the push button color selector still functions.You can get RED selection at that low voltage, but not the other colors, blue being the worst.Divide that out, comes to 0.73 volts available to any LED with resistor.

author: RJSV
author_rank: Super Contributor
timestamp: July 03, 2023, 09:34:35 pm
content: ...mouse likely uses a white LED, so yeah, function gets very compromised on any mouse (although red LED maybe more tolerant.

author: james_s
author_rank: Super Contributor
timestamp: July 03, 2023, 09:37:17 pm
content: Quote from: eeguy on July 03, 2023, 07:32:46 pmDid you measure them under load? With no load the voltage will be higher.Duracell is among the worst brand of batteries IMO. They have very slick marketing but the product is crap, they are notorious for leaking.

author: RJSV
author_rank: Super Contributor
timestamp: July 03, 2023, 09:38:57 pm
content: BTW, my trusty digital temperature meter is often abused / neglected on 'low batt' status for almost two years, and seems OK (digital on liquid crystal).

author: ArdWar
author_rank: Frequent Contributor
timestamp: July 04, 2023, 12:20:50 am
content: Out of curiosity I measured a couple of used AA that my wireless mouse (Razer DA V2X) won't accept anymore. It took single AA, I just have a bunch of used batteries in my drawer from my gaming sessions over timeKeep in mind this is "spot check" and the voltages do fall with time.HiZ(?) 1u 10u 100u 1m 10m1.226 1.223 1.222 1.223 1.221 1.2101.288 1.288 1.287 1.287 1.285 1.2851.231 1.231 1.230 1.230 1.227 1.2101.367 1.334 1.335 1.336 1.336 1.333So yeah, not quite dead yet.Measured the last one with 10mA current draw over 3 minutes. Still think it's not quite dead yet

author: JustMeHere
author_rank: Frequent Contributor
timestamp: July 04, 2023, 12:29:32 am
content: Quote from: radiolistener on July 03, 2023, 08:49:15 pmFull charge on these is 1.2V. Going down to 1.1V seems like it shouldn't hurt them that bad.

author: radiolistener
author_rank: Super Contributor
timestamp: July 04, 2023, 03:13:42 am
content: Quote from: JustMeHere on July 04, 2023, 12:29:32 amNo, 1.2V Ni-MH battery has full charge voltage at about 1.4-1.5 V.Full discharge threshold is at 0.9 V, but its going very fast from 1.0 V to 0.9 v (about several seconds), and it's not recommended to discharge it below 1.0-1.1 V.At 1.1 V it remains about 5-20% of charge, depends on battery model.At 1.0 V it has 0% of charge.Here is EMF voltage vs residual charge curve for Ni-MH:But note, full charge voltage for Ni-MH depends on exact instance of the battery, you're needs to check -dV/dt event to stop charge, do not use voltage for that.

author: Shonky
author_rank: Frequent Contributor
timestamp: July 04, 2023, 08:18:58 am
content: Quote from: schmitt trigger on July 03, 2023, 08:48:50 pmYou don't put cells in parallel in a mouse for higher current delivery. It wont draw significant current or you'd be replacing them too often and complaining. Would only be for capacity but still strange. Are you sure they're in parallel even?

author: RoGeorge
author_rank: Super Contributor
timestamp: July 04, 2023, 09:41:14 am
content: Quote from: eeguy on July 03, 2023, 07:18:57 pmYes.There is not much energy left in alkaline batteries when the voltage drops under 1.2V, particularly when the load is a low current PC mouse.For the mouse, use low self discharge NiMH rechargeable (mine are branded TRONIC, sets of 4 from LIDL). One charge will last as long as an alkaline battery would last, except the NiMH can be recharged hundreds of times. I have some from 2012, they are still working very well with my A4TECH wireless mouse.

author: james_s
author_rank: Super Contributor
timestamp: July 04, 2023, 06:38:51 pm
content: Quote from: ArdWar on July 04, 2023, 12:20:50 am