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ArcticMyst Security by Avery

Just ordered a 1W 501B from sci-fi!

Feb 19, 2016
edit: Forgot to mention, the batteries are fine, they fully charge, I've metered them and their voltage is fine-- better than, actually. They're rated 3.7V, but one came out at 4.17V.

After my laser died, I got my batteries tested too and got the exact same results. I had them tested at an electronics store. Right away after I heard about the voltage being higher than specified, I figured the higher voltage probably fried my laser's diode, but the technician told me that a higher voltage reading is actually normal. He said that anything below 3.7v is considered "dead" on a 3.7v battery, and that they should be closer to 4.1 or 4.2v when charged. That kind of surprised me since regular AA batteries are 1.5v, yet rechargeable AA batteries are only 1.2v, and they aren't "dead" at all.


Mar 17, 2006
You're talking about 3 different battery chemistries here. First off Li Ion batteries are not dead at 3.7 volts so you can through that idea out the window. Secondly you should never let the battery drain past ~2.8 volts without causing irreversible effects. When fully charged they are actually 4.2 volts so that part is accurate. Thirdly AA nonchargeable batteries are alkaline batteries and rechargeable batteries are either NMHD or NiCadiums so the voltage is not the same as alkalines. Really this is battery basics people.
Correct on all counts.