The Battery

[hisoka147]

The recommended battery to use for this detector is the a 12 volts 1.2AH but I bought a 12 volts 7AH battery because the required one is completely not available here at my place. I'm having some trouble understanding this AH, does it means amperes? but the battery I bought that states 7AH has an initial current of 2.8 Amp

[Qiaozhi]

The recommended battery to use for this detector is the a 12 volts 1.2AH but I bought a 12 volts 7AH battery because the required one is completely not available here at my place. I'm having some trouble understanding this AH, does it means amperes? but the battery I bought that states 7AH has an initial current of 2.8 Amp

AH stands for Ampere-Hours. It is a measure of how much energy the battery contains.

In other words - if you discharged a 12V 1.2AH battery at a rate of 0.12A per hour, it would last 10 hours. But if you discharged it at a rate of 1.2A per hour, it would last 1 hour.

[mindfree]

Hi,
Please also recommend good brand batteriies to be used with home made detectors. Also what type Pb, Ni-MH or Ni-Cd.

[hisoka147]

AH stands for Ampere-Hours. It is a measure of how much energy the battery contains.

In other words - if you discharged a 12V 1.2AH battery at a rate of 0.12A per hour, it would last 10 hours. But if you discharged it at a rate of 1.2A per hour, it would last 1 hour.

I see thanks for the explanation. My battery has a 7AH rating and I guess I'm using around 0.350A per hour which result to 20 hours for my battery to be discharged. Anyway, I'll try to check further more about it.

Anyway, I already tested the battery and it is working perfectly just fine. Now, my next project is to create a Charger.

As to the person asking about a good battery, I recommend a Sealed Lead Acid just like what I am using because it will last a longer time.

[Qiaozhi]

Now, my next project is to create a Charger.

It is cheaper to buy a charger for a lead-acid battery than it is to build one.
http://www.maplin.co.uk/Module.aspx?ModuleNo=27701

[hisoka147]

Sad to say I already bought the components to make a charger. I'm building the charger recommended by Gary suitable to this metal detector.

Anyway, does anybody around here know's how to place an indicator when the battery is already fully charge?. My idea about this is to use a relay switch. Please share your idea and it is greatly appreciated. Thanks

[chemelec]

Sad to say I already bought the components to make a charger. I'm building the charger recommended by Gary suitable to this metal detector.

Anyway, does anybody around here know's how to place an indicator when the battery is already fully charge?. My idea about this is to use a relay switch. Please share your idea and it is greatly appreciated. Thanks

Typically this detector draws about 100 to 120 ma, so a 7AH battery will probably last 60 Hours.
But it is a Pretty Heavy battery.

[hisoka147]

Typically this detector draws about 100 to 120 ma, so a 7AH battery will probably last 60 Hours.
But it is a Pretty Heavy battery.

Yap it's a very heavy battery but I don't have any problem carrying it around because I am strong person.

I have built your charger and it's working perfectly.

Previously, I was asking anybody's idea about making an indicator when the battery is already fully charge. I have now the solution for that and I want to share it to everybody.

When we are going to charge a battery, we really can't tell if it's already fully charge but not unless you have to use your Multi-Meter. So we tend to rely on using time period. I usually charge my battery for straight 12 hours.

Now what I did was, I have an electronic manual clock with a timer. I did some modification on the circuit of the alarm to trigger the on and off of my charger. I guess any electronic expert can already grasps the idea since it's way too simple.

I can now charge my battery and leave it away without any worries. For example, I can set it to charge for 10 hour period. I have to adjust the clock timer and the alarm to turn off the charger after the 10 hour period has ended.

And I forgot, remember to disconnect the speaker/buzzer alarm.

[chemelec]

Yap it's a very heavy battery but I don't have any problem carrying it around because I am strong person.

I have built your charger and it's working perfectly.

Previously, I was asking anybody's idea about making an indicator when the battery is already fully charge. I have now the solution for that and I want to share it to everybody.

When we are going to charge a battery, we really can't tell if it's already fully charge but not unless you have to use your Multi-Meter. So we tend to rely on using time period. I usually charge my battery for straight 12 hours.

Now what I did was, I have an electronic manual clock with a timer. I did some modification on the circuit of the alarm to trigger the on and off of my charger. I guess any electronic expert can already grasps the idea since it's way too simple.

I can now charge my battery and leave it away without any worries. For example, I can set it to charge for 10 hour period. I have to adjust the clock timer and the alarm to turn off the charger after the 10 hour period has ended.

And I forgot, remember to disconnect the speaker/buzzer alarm.

If your only charging your battery at a Low Current and limit the Charge Voltage to 13.6 Volt, you will never Over Charge it.

[hisoka147]

Yap read it already from your website about the reason why. You've got a very nice website and I'm planning to do other projects beside the PI detector. Keep it up