[bladesmith]

I have a 12 volt battery power supply for my buffer. I would like to add a meter to it.
Just to know exactly what condition my supply is in/at.  But, not sure if a typical volt meter would be best or
Maybe an ampere meter might be better. I am currently using a 12 volt beep cycle (marine type ) battery.

Any ideas/suggestions ?

Thanks

[mikeeastman]

The amp meter is only going to give the draw, not the battery charge. Here is basic volt meter http://www.solar-electric.com/blsea80anvom.html and here is one I modded and use. http://www.solar-electric.com/mnbcm.html

[TrungT]

2 wire DC 12V panel meter

[jtwrace]

More importantly, you should NOT be using an open acid battery inside your house.  One little spark.....




Get yourself a sealed battery. 

[Davey]

+1 on that!  Get that battery out of your listening room.

Dave.

[bladesmith]

The capacity meter  ( http://www.solar-electric.com/mnbcm.html ) is interesting.

How do I know when I need to recharge with this meter, at what voltage level will it reach when it is needing recharging ?
( It seems that I can run this battery almost all the down to about 10% charged,  then it needs recharging , would it be slighty different for every application.  )(http://www.ebay.com/itm/Two-Wire-DC-12V-Digital-Voltage-Panel-Volt-Meter-3-50-30-0V-Green-LED-Voltmeter-/371023561723?pt=LH_DefaultDomain_0&hash=item5662ba43fb&afsrc=1)

This is easy to read. http://shop.pkys.com/Blue-Sea-Systems-1050-DIN-Voltmeter-DC-8-16V_p_263.html

[bladesmith]

More importantly, you should NOT be using an open acid battery inside your house.  One little spark.....




Get yourself a sealed battery.

Yea, I have sparks all over my living area.   .. I have had batteries actually blow up in my face, and it requirs a large amount of fumes and a very leaky, poor battery, along with a very large sparking source. Being struck by lightening is more likely. But, thanks for your concern.

[Davey]

Yea, I have sparks all over my living area.   .. I have had batteries actually blow up in my face, and it requirs a large amount of fumes and a very leaky, poor battery, along with a very large sparking source. Being struck by lightening is more likely. But, thanks for your concern.

I think you're missing the point. 

Regardless, I would recharge when the loaded voltage goes below 12.0 volts.  Any type of (accurate) DC voltmeter will be sufficient for this job.
A better setup might be to use an SLA battery and leave a battery tender (or similar) on it all the time.

Stay safe.

Dave.

[jtwrace]

Yea, I have sparks all over my living area.    .. I have had batteries actually blow up in my face, and it requirs a large amount of fumes and a very leaky, poor battery, along with a very large sparking source. Being struck by lightening is more likely. But, thanks for your concern.

If you say so.  Consider yourself warned.  The guy that burnt his house down to the ground never thought a 9V battery would do that either. True story and it happens.

I think you're missing the point. 

Regardless, I would recharge when the loaded voltage goes below 12.0 volts.  Any type of (accurate) DC voltmeter will be sufficient for this job.
A better setup might be to use an SLA battery and leave a battery tender (or similar) on it all the time.

Stay safe.

Dave.

Yes.  I use this CTek charger on all smaller 12V batteries.

[mikeeastman]

For best battery life its best to charge battery when they reach the 12.4 -12.3 volt range.

[bladesmith]

If you say so.  Consider yourself warned.  The guy that burnt his house down to the ground never thought a 9V battery would do that either. True story and it happens.



Yes.  I use this CTek charger on all smaller 12V batteries.

Your video is about a sealed battery and improper disposal, neither of which this thread is a subject of.

[Wayner]

To measure the voltage, you need to connect across the poles. To read current, you need to be in series.

Which kind of means 2 different meters if you are looking for a permanent install.

Velleman has some nice meters for this stuff....

[*Scotty*]

bladesmith, when a lead/acid battery of the type you have charges it produces HYDROGEN GAS, remember the Hindenburg. When you confine the hydrogen gas,as you have done in your very nice looking battery box, the chances of an explosion are multiplied.
Scotty

[Davey]

I think bladesmith is aware of and/or not concerned with the possible safety issues.  (No need to keep beating him up on this.)

The original question regarding voltage monitoring has been answered, so there's really not much left to discuss.

Cheers,

Dave.

[bladesmith]

bladesmith, when a lead/acid battery of the type you have charges it produces HYDROGEN GAS, remember the Hindenburg. When you confine the hydrogen gas,as you have done in your very nice looking battery box, the chances of an explosion are multiplied.
Scotty

(Now, I have the Hindenburg in my living room,  )

Have you even read the title to the post ?

Or do you just go around thread killing ?

[MarvinTheMartian]

Everything you need to know.....
http://batteryuniversity.com/

And what you will eventually need...
http://www.davidsonfireextinguishers.ca/

Hope your progeny survive Shawn

[wakibaki]

He's probably right. That battery box is not going to confine hydrogen.

If you hadn't issued a safety warning I probably would have, though.

Building a battery meter is notoriously difficult. Even if you count every milliamp-second in and out, you still have self-discharge to account for. Traditionally, lead-acid batteries are managed with a voltmeter and an experienced eye. In days gone by a hygrometer would have been employed too, but we just top batteries up to a level with distilled water now, if at all.

It's a nice little project to build with a PIC though.

w