DIY 18650 Li-Ion battery voltage checker

Finaly I've made battery checker from nonfunctional cheapo charger and 1s-6s Li-Po checker:

- http://www.dealextreme.com/p/18650-digital-battery-charger-3499

- http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160519324659&rvr_id=244430326862&clk_rvr_id=244430326862&mfe=sidebar

Disassembled charger with a hole for 1s-6s:

Put all together into functional one

and ductaped

See all other (not so good) pictures at: http://picasaweb.google.com/mojmailbox/LiIonBatteryChecker#

Very cool !!!

Yup it's and highly acurate +/- 0.01V.

I was wondering how the voltage meter handles multiple cells. Does it continue reading out the voltage of the unconnected cells? (cells (2),3-6)

No, it cycles readings trough all cells it can find. In this case only one, so it shows only the one you are testnig. It does blinking between readings trying to find next, but it's not annoying. And it consumes very little power from the battery.

So what does it do for the unmeasured cells? What do you mean by blinking?
Sorry for the questions, I’m just curious because I’ve ordered a similar one last week, I guess it should be arriving next week or so. I’m just looking for a very compact single cell volt meter I can incorporate into a battery pack.
One I had earlier would cycle through all 6 cells, even if they measured 0 volts. So what I’m after is one that only shows the voltage of the connected cells, and no zeros.

It does nothing for unmeasured cells. By blinking I mean - well take a look at - you could find it by yourself ;-)

http://www.youtube.com/watch?v=CN6L5ZJRs2w

Did you ordered same type? Where (link it) and at what cost?

nice job! i have a TF charger that does not shut off and just keeps charging. i think ill give this a try. Thanks!!!

Fancy. Personally i like more a trusty charger but being able to guess when the cell will be fully charged is really nice to have. Good job!

The voltage meter thingy in this might work really well with the 5packs of 18650 holders on ebay. Nice find.

You might get it bit wrong. It's just a checker. The charger doesn't work. In fact I took out all the electronics. Still your idea isn't bad. BTW I'm mostly using XTAR WP2 and Ultrafire TR001.

Cool to have videos these days. Mine looks to be similar to the one you have interns of layout and design. The UI seems pretty similar across most of the current volt meters now. I’ll try to find a link later from eBay.
I like the way it handles the single cell, it’s pretty smart now. The ones that I was looking at a year ago would simply flash through all cell voltages and start again, so you get slot of zeros.

You might use also 2s-6s checker, but you have to check at least two batteries at same time. AFAIK those are not so accurate and you might get a bit different electronics as shown on pictures. Still usable

http://cgi.ebay.com/2s-6s-Lipo-Battery-Voltage-Indicator-Checker-Tester-LED-/180627319118?pt=Radio_Control_Parts_Accessories&hash=item2a0e3a294e

Oh, silly me... si it is just a fancy voltmeter?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170646599283&ssPageName=STRK:MEWNX:IT#ht_4172wt_1141

This is the one I bought.

That is the same as I have used, just the other seller. Good choice!

I would recomend this 1s-6s type only, not 2s-6s red one if someone is going to use it.

The indicator is specified to be used for Li-Po batteries. Does this mean it will not work on other batteries like Li-Ion?

plugging the batteris into your icharge will do the same thing and it has monitor mode as well as im sure you know, but these are great if people dont have hobby chargers and they are great out in the feild not at home near your charger or DDM.

It works with Li-Ion just fine. See description:

Precision: ± 0.01V
Voltage test range: 2.8V - 25.2V
Test accuracy: ± 0.005V
Dimension: about 25 x 23 x 10 mm

Thanks ledoman, I might have to get a few of these to monitor the sate of my battery chargers.