Nervous battery issue

Hello.

I recently ordered a 2W blue laser and these googles for safety.
I also got these batteries which are my issue. They say they're 3V but I checked them with a multimeter and the multimeter says it's at 4.2v. I'm worried that will blow my laser since it says it requires 3.7V. I don't currently have the laser since it's still being shipped. My question is am I able to put in those batteries and use my laser without the worry of it breaking?

Also, if anyone is able to send me a link to some good batteries that will work and a charger, I'd be more than willing to buy them.

Hi, did you look at the reviews before buying those batteries? It shows it has 3 1/2 stars for reviews. If you look at the customer reviews 35 are good, but 25 are bad. I would never buy a product that had so many 1 star reviews compared to the good ones. As for better batteries and a charger, I would definitely recommend
Nitecore Intellicharge i4
And these batteries have worked well for me and will work with that laser. 2 of them.
16340 Nitecore NL166 650 mAh Protected Button Top
I would try and return the ones you got on Amazon just because of all those 1 star ratings.
Welcome to the forum!

It's very normal for lithium-ion batteries to be at 4.2V when fully charged. When almost dead they will have a voltage of less than 3.2V. Lithium-ion battery voltages vary widely based on state of charge. If the laser you bought is built with common sense, it's driver should be able to handle a wide range of input voltages (2.8 - 4.5V) if it is designed to use lithium-ion batteries. So, the batteries you got may have poor reviews and genuinely suck (in terms of current output and life cycle), but they will not break your laser. Besides, lasers aren't voltage driven, they are current driven. You're fine