solar cell, 9v battery, indicator circuit

Reply

  #1  
Old 12-12-12, 01:52 PM
Member
Thread Starter
Join Date: Dec 2012
Location: United States
Posts: 13
solar cell, 9v battery, indicator circuit

I am looking for a little advice on some circuit work. I want to have a 9v battery powering some LED lights. I already have the schematic for that circuit. I also want this battery attached to a battery level indicator circuit. It will be a rechargeable 9v battery, and I want to use a solar cell to recharge it. So it would be solar cell to 9v battery to indicator circuit and also 9v to LED circuit. If I was too vague just let me know.
 
Sponsored Links
  #2  
Old 12-12-12, 07:02 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 46,213
First thing......just so you are aware.
A regular 9 volt battery is made up of six 1.5 volt cells. 6 x 1.5 = 9v
A chargeable 9 volt battery is made up of seven 1.2 volt cells. 7 x 1.2 = 8.4v

So first your circuit needs to be based on a battery voltage of 8.4 volts.
Second....a battery charge meter would take up valuable storage capacity.
Third....with LED's run on a battery of this type you will have a short lamp duration.

You don't mention your application but I would lean towards a small sealed lead acid type battery. If you went with a 6 or 12 volt one you would have plenty of storage and the solar cell could just loaf along.

On edit: It appears that there may be NiMh 9 volt chargables that have higher voltage.
 
  #3  
Old 12-13-12, 08:55 AM
Member
Thread Starter
Join Date: Dec 2012
Location: United States
Posts: 13
I am building a DVD case with sliding doors. I will have 18 5mm LEDs that turn on only when the sliding door is open, so they may only be on for 20 seconds at a time a few times a week. The battery indicator isnt completely necessary, but I know even rechargeable batteries die at some point. I figured if I install a blinking LED somewhere in the circuit it would be nice. And as you may have guess, I just want the solar cell to keep recharging the battery. I figured it would work the same way as a calculator.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes