Powering Some LED Garden Lights

[Turtle Shed]

Hello all.

I'd like to power five strings of garden LED lights from the 7.2v rechargeable batteries I have. The lights normally take a 1.2v supply but they work fine off of 1.5v.

So if I connect the light string in series, will that equate to a suitable voltage requirement of around 7.5v? Or do LEDs not work like that?

If that will work I believe I then need a resistor in series with them. How do I calculate the size of resistor please?

Basically I'm trying to avoid using the little solar panels as they don't work very well in winter. I could just use rechargeable AA batteries, but I have a lot of the bigger batteries lying around. (These, but slightly higher capacity: https://www.amazon.co.uk/Rechargeable-Replacement-...

Cheers

[OutInTheShed]

To drive LEDs from 1.2V implies some sort of power conversion.
So it's possible things will go wrong if you just wire them in series.

[geeks]

I'd be chucking in a voltage converter in there

[Mr Pointy]

How many Watts is each string? Knowing that we might be able to work out the dropper resistor/s needed.

[Turtle Shed]

Well these are the lights in question:

https://www.amazon.co.uk/dp/B08BZNS7KP?psc=1&r...

I can whack a multimeter in series to advise on current draw, and will do so later.

I could just power them from a D cell, they're 1.5 volts of course and would probably run the things for a couple of weeks, but I just like to tinker and learn, and having got a plentiful supply of a different type of battery this is indeed a good tinkering chance with PH knowledge.

For additional info the black box has a little solar cell, there's a 1.2v rechargeable AAA battery inside, and a light sensor to turn them off during daylight hours. Other electronic trickery allows for various illumination modes, but my requirement is that they just stay on solidly.

[biggiles]

1.2v - so these run off NiMH rechargeable batteries. A single battery AAA in this case.

NiMH can be charged and discharged in parallel, so you could rig up 10 or 100 batteries to give you more capacity between sunny days.

Probably easier than trying to use 7.2v (double Li-Ion cells?).

[Turtle Shed]

biggiles said:

1.2v - so these run off NiMH rechargeable batteries. A single battery AAA in this case.

NiMH can be charged and discharged in parallel, so you could rig up 10 or 100 batteries to give you more capacity between sunny days.

Probably easier than trying to use 7.2v (double Li-Ion cells?).

AA batteries in this case, and I did actually hook up eight in parallel and they lasted about ten days. Will probably go down that route, just wondered about the alternative.