Short version:
Can't really understand if and how zener diode or LM3914 can be made to work for my battery level indicator for LED strip that draws about 800 mA when connected directly to a 12v SLA battery. I feel that they really would not help me here since SLA batteries below ~11v are considered empty or drained or do I need to play with voltage dividers/resistors.
Long version:
I am building a LED lighting for my pantry. Since there is no readily available outlets and to avoid having to hire electrician to wire up one I had to resort to a SLA battery to provide power to LED strip, at least for now. I've already built up a circuit that allows me to control brightness using PWM. But now I've realized that since I can vary brightness manually it becomes harder to catch a moment when battery needs to be recharged to avoid draining it completely.
So, I started looking for a circuit examples that give me at least 2-3 point level indicator. There are tonns of tutorial that use zener diodes and some using IC LM3914 which seemed to be reasonable to me at first sight. But when I started researching more about SLA voltages I found that SLA batteries below ~11V are considered dead. Which brings me to my confusion point. Is that voltage they are talking about is load voltage or no-load voltage?
Wouldn't battery voltage vary depending on the load or good and compatible battery should be able to provide 11-12v irrespective of the load? If an acceptable voltage range is only within 1-2v how can zener diodes or LM3914 be really used here or can they? Or you have to play around with voltage dividers/resistors to trigger corresponding level LED?
Anyone is able to tell me if and where I am right or wrong?
Any help is appreciated.
Thanks
Can't really understand if and how zener diode or LM3914 can be made to work for my battery level indicator for LED strip that draws about 800 mA when connected directly to a 12v SLA battery. I feel that they really would not help me here since SLA batteries below ~11v are considered empty or drained or do I need to play with voltage dividers/resistors.
Long version:
I am building a LED lighting for my pantry. Since there is no readily available outlets and to avoid having to hire electrician to wire up one I had to resort to a SLA battery to provide power to LED strip, at least for now. I've already built up a circuit that allows me to control brightness using PWM. But now I've realized that since I can vary brightness manually it becomes harder to catch a moment when battery needs to be recharged to avoid draining it completely.
So, I started looking for a circuit examples that give me at least 2-3 point level indicator. There are tonns of tutorial that use zener diodes and some using IC LM3914 which seemed to be reasonable to me at first sight. But when I started researching more about SLA voltages I found that SLA batteries below ~11V are considered dead. Which brings me to my confusion point. Is that voltage they are talking about is load voltage or no-load voltage?
Wouldn't battery voltage vary depending on the load or good and compatible battery should be able to provide 11-12v irrespective of the load? If an acceptable voltage range is only within 1-2v how can zener diodes or LM3914 be really used here or can they? Or you have to play around with voltage dividers/resistors to trigger corresponding level LED?
Anyone is able to tell me if and where I am right or wrong?
Any help is appreciated.
Thanks