Voltmeter!

[Kaw1000]

Hello..I'm new to this forum, good to meet you all..I've learned a ton from all the heli forums,and I'm sure I will learn alot more here!!

I've got a voltmeter here,and have been reading about you guys testing batterys and so forth.I'm not sure on some of the setting on this volt meter. when I check my volts on a lipo what setting on the voltmeter should I use?

The sttings are as follows....vdc...with the #'s 20...200 and 600.....vac with the #'s 200 and 600.......adc with #'s...10a....200m....20m.....2000

I played around with it a little and it seems that its show that my lipos are charged a littlebit more that the label says...example...a 11v lipo reads 12.8v

also I have soldered deans connectors to my lipos and chargers...being a noob :oops: .....I soldered the negitive wire on the postive on the deans connector....and of course...the positve on the negitive on the deans connector...also did the same thing on batterys...they all matches up
Is it ok to leave it this way or do I need to reverse them even though they all match up?

Thanks

[medtech]

even though they will work fine being soldered incorrectly it is considered very bad to have them reversed. It can also be dangerous and could damage things if someone unknowing finds out. It really should only take you a few minutes to swap them around. I'd do the right thing and fix them!! You'll feel much less like a noob! 8)

As far as the voltmeter, VDC is DC volts, VAC is AC volts (common household voltage), and the other setting is for current (amps). The numbers are the high end of the scale you want to use, just to set sensitivity. Under 20V use the 20 setting, if you're going to measure over 20 volts, you'll have to switch to 200.

Batteries can always hold a bit more voltage than the label says!! As long as it's close you're fine!

[Kaw1000]

Thanks med...that clears up alot!!......I'm converting a cigrette plug to charge my batterys....I'm going to solder a deans to the end of it.
The wires are both black...is the rule of thumb that the wire with the writing on it is the positive wire??

[swatson144]

You can't do that! Unless you mean an adapter to power a charger. If so it is usually best to use some other connector on the input power than the output. I usually use bannana jacks as the fancy ones allow you to clip on a battery clip, plug in a B plug, or act as plain wire terms.

The 12v car battery is 13V plus. so you'd need a current limiter to keep the charge rate in check ( below 1C) and a voltage limiter to keep a pack below 4.2V/cell. In other words you need a Lipo charger between the battery and the lighter. It sounded as if you might be heading that way.

Steve

[Kaw1000]

Yes, what I have is a jumper box used to jump cars....it has a outlet that you can put a cigerette type adapter in.......I was going to solder deans to the end of that wire and then those wires will go to charger the lipo to charger!!

http://i29.photobucket.com/albums/c261/Kaw1000/119_1939.jpg

Here is the set up only im not going to use alligator clips on the jumper ends...I want to use the 12v outlet instead!

[swatson144]

That'll work.

The plus is the middle of the lighter plug.

You can use the Ohms feature of your meter to see which wire is connected to it. It's the upside down U looking setting. If you touch a lead to the center then touch the other lead to each wire you should see that 1 will give a very low resistance measurement (like when you touch the 2 leads together. The other should look like you never connected anything.

Steve

[Kaw1000]

So....the wire with the writing on it is or is not the positive...I always thought the the rule of thumb is the wire with the writing on it was the positive.....I will try the omh thing and see..........Thanks for all your help

[thanhTran]

a digital voltmeter should show you which wire is (+) and which wire is (-), If you have it reverse it shows up with a negative value on the meter. Interestingly, I have one of those car jumping battery too. I use solar power to charge it and use it to charge my lipo cells. I can let the sun charge it for a few daya and I can chage the lipo once or twice before I have to wait for another few days ;)

Thanh