Building stuff like this is almost never cheaper than buying.

Once you factor in all the details, never mind what you time might be worth.
And it might not work?
And you might blow up a bunch of expensive parts?

Only worthwhile as a hobby / learning adventure.

 

@oz93666…how can you run a 32 volt COB with a car battery? I mean without a booster module.
As to driving the 10 watt COBs:
I would place several in a cluster and select a resistor that would drive each one at around 400mA @ the center of the voltage range. (one resistor per COB)
This gives you plenty of headway, and be sure to use a proper heat sink. (heat sink and proper derating is the key here)
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Yes ... you would need a booster ... I was thinking more about what a car battery could comfortably output in Watts ...

You could use 12V cobs ,but they only come in low power units up to 10W then the current gets large for over 1Kw

This is the only case where it's a good idea to run the leds at max recommended current ... they only pulse , perhaps on only 10% of the time so no heat sink needed .

TS ... this a very easy project , you can buy modules that do this for cars and motorbikes on eBay for a few $ ...

I'm sure you can find strobe modules with variable timing too ..

Or if you want an education as well there's this kit ....

Once you have a flasher you can feed the output into a solid state relay to switch KWatts of light

This one is perfect for use with 100W cobs ... can switch up to 60V @ 100A (6Kw) ..just $7

You could build an awesome strobe that would disable any intruder very cheaply.