Hi everyone thanks for reading my thread I have 100 LED lamp ( the big ones not the regular 5 mm type ) I need to wire those all in one circuit and providing them current from one or two 9 v battery ( as needed ) I'm asking for a way to do it .. Questions I'm having in mind: Should I sold a resistor to every LED or just one next to the battery .. Should I just ingore resistors and sold them in two parralel groups ..
Any help would be appreciated If anyone is experienced anough to give me a way to wire them and resistor value to use

 

What are the manufacturer and part number for the LED, or what is the forward voltage (Vf) and what curret do you want to run through them? Also, how long do you want the LEDs to light? I doubt that two 9 V batteries have enough power to do what you want, but there is no way to know for sure without the specifications for the LED.

ak

 

I dont know the specifications :/ in my country sellers dont know a thing about their product .. However i operated the blue ones 40 one on a 9v battery

 

 

A 9 volt battery has very limited current capacity, (high internal resistance) lighting 100 LED's on one 9V battery is possible if the current is very low, but you are not going to get much in terms of brightness or battery life.

 

Those look like 8mm LEDs so they are the same 20mA die as 3mm or 5mm LEDs but in a bigger blob of epoxy.

 

A typical PP3 battery may last a few minutes with this kind of load; does that suit your requirements?

 

If they MUST be battery powered, you may want to consider a 12V SLA battery (though they are expensive) or a "battery pack" of around 8 or more AA's

Also, you need to consider the cable diameter you use to wire them all up. 100 of those LED's are likely to draw at least 2A so use at least 3mm²

 

I can use two 9v together no problem if these leds wont be damaged so I wont need any resistors?

 

Also, you need to consider the cable diameter you use to wire them all up. 100 of those LED's are likely to draw at least 2A so use at least 3mm²

At least 3mm², are you sure?

 

Guys this is what i have in mind now .. I wire every 50 led in parallel then those two groups in serie with a 9v and a 4,5 v together would that work ?? ( 13.5 v total )

 

A 9V PP3 battery typically has a 250mA current capacity, really not that much. 2 PP3's in parallel will give you about 0.5A, still not that much considering your load will be over 2A. The batteries will last about 15 minutes before the LED's start to dim and they'll be completely dead after about 20-25(max) minutes.

Consider AA's, wire 6 together is series to get 9V and use rechargeables (as they have a high current capacity, up to 3.5A each).

Or, you'd be better off connecting 6 AA's as 3 groups of 2 to give a lower supply voltage of 3V but a higher current capacity of 10.5A (assuming you use those 3.5A cells). This way your arrangement of 100 LED's will last hours instead of minutes

 

At least 3mm², are you sure?

Maybe 2.5mm² but I don't know the length of his cable run

 

Im gonna wire them directly no wire used a led is solded into the next one .. Also we do not have good AA here they are super expansive but we have those cheap made in china ones would that still work?

 

Im gonna wire them directly no wire used a led is solded into the next one .. Also we do not have good AA here they are super expansive but we have those cheap made in china ones would that still work?

You know, someone asks how to power LEDs almost every day here, it is the single most common topic. If you need to know the correct way to drive LEDs, search the many existing threads or, just google the subject.

There is little point in going through the basics of driving LEDs again when it has been covered multiple times.

 

I googled n searched but no one did it this way :/ the question is simple here x) if I use 9volt x2 would I need resistors? Do i need resistors at all ? Im so stuck here :/

 

Ok, if you read about powering LEDs that blocco suggested, you should have realized by now that you're going to need resistors. Which value depends on the specifications for the LEDs, that you don't seem to have.

 

What color is the light that you LEDs make?
This information will help us guess at the required voltage.

 

50 are green .. 20 orange and 30 blue ones

 

Always limit current to an LED. Lets assume your LED's have a Vf of 3.3V and a current consumption of 20mA

Vr=Vcc-Vled

Vr=9-3.3

R=Vr/Iled

R=5.7/.02

R=285 (round up to closest real resistor value: 300R)

...so a 300ohm resistor in series with each LED.

No wires? LED leads can only handle so much current, use wires.