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Lithium AA/AAA Batteries for Use in Electronics

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Boris_yo:
Hello,

I was wondering whether lithium batteries are too strong for delicate electronic devices like blood pressure meter for example.
What attracts me to lithium batteries is that they do not leak and I also think they supply higher voltage because compared to rechargeable NiMH LSD batteries, they provide more power. My hair trimmer works louder and stronger for example and my flashlight shines brighter.

I remember reading that only AA alkalines should be used for blood pressure meters. I don't know why NiMH LSD batteries are not good for that. Would they negatively affect accuracy of test? I noticed also that NiMH batteries have 1.2V while alkalines have 1.5v so maybe this is why NiMH should not be used in blood pressure meters? Haven't heard anything mentioning lithium batteries though.

cortex_m0:
Are we talking about Lithium Ion (aka Lithium Cobalt), which have a nominal voltage of 3.7V or Lithium Iron Disulfide which has a nominal voltage of 1.6V?

Lithium Iron Disulfide should be fine for any device which has internal voltage regulation, which will include is most electronic devices. I obviously cannot speak to your particular blood pressure meter.

Lower voltage types, like NiMH, may cause devices to drop out too soon, since a 1.2V Alkaline cell is nearly dead. Suppose you have a 5V supply rail in a device powered by 4x AA batteries. When fresh, the supply will be a solid 5V. With NiMH, the regulator can never reach the nominal 5V because the fresh batteries only total 4.8V.

deadlylover:
Off the top of my head, my old Omron blood pressure monitor only depletes around 20% of my eneloops before complaining. I don't know what the cutoff voltage is but it must be very high in the ~1.30V range for that to happen.

I don't mind changing the batteries 5 times as often because it still lasts a few months with occasional use. (saves money and stops primaries ending up in the landfill)

I would imagine anything "important" will just shut down before battery voltage will impact function/accuracy. I use IKEAloops anywhere and everywhere I can.  :P

NiHaoMike:
There are rechargeable lithium AAs that have built in voltage regulators.

Boris_yo:
I have Black and Decker alkaline battery-operated screwdriver. It's battery compartment mentions to use only AA alkaline batteries. Why can't I use NiMH or lithium batteries?

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