# Review: voltage reference

**URL:** <https://community.electricforum.com/t/review-voltage-reference/6278>\
**Category:** Battery & Chargers\
**Created:** [July 30, 2016, 2:57pm UTC](https://community.electricforum.com/t/review-voltage-reference/6278 "2016-07-30T14:57:13Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Inwo](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.electricforum.com/inwo/32/1067_2.png) [@Inwo](https://community.electricforum.com/u/Inwo)\
**Post date:** [July 30, 2016, 2:57pm UTC](https://community.electricforum.com/t/review-voltage-reference/6278/1 "2016-07-30T14:57:13Z")

</div>

With lithium batteries, a few mv can be important.  
Ever wonder how well your tool box meter is holding up?

$10 and a 9v battery connector gets you a 4.096 volt precision source.  
Connect voltmeter. It’s that easy.

Then either calibrate meter or mark it, as I did mine.

Ie. reads .01 volts low at 5 volts.

One of mine was spot on, reading 4.10. Only reads to .01v on 20v scale.

Can’t wait to get my 7s volt monitors that read to 1mv.