Reddit mentions of DROK 091016 DC-DC Buck Converter 4-38V Step-down Voltage Regulator Module Adjustable Current 5A Max 75W High Power Volt Power Supply Transformer Board with Constant Current & Voltage

mAh is a measure of capacity. If you are connecting to a wall outlet, that part is irrelevant. You just need something that outputs 1.5 volts at enough current which might be a little tricky to figure out.

So I saw one wall adapter that does 1.5v but only at 500ma which I don't know might not be enough.

You could use this

https://www.amazon.com/gp/aw/d/B00VUHVX6W/ref=mp_s_a_1_9?ie=UTF8&qid=1491453675&sr=8-9&pi=AC_SX236_SY340_FMwebp_QL65&keywords=step+down+converter

And have the input come from like a 12v adapter and output to your device at 1.5v and power probably won't be an issue. But you'll need a multimeter to test the voltage. Or I've seen some of these with an actual voltage readout. But you have to be sure that it's a stepdown converter and that it will go as low as 1.5v.

You may be able to do something like this:

Use an RC/Drone LiPo battery: https://www.hobbyzone.com/batteries/lipo/4-cell/ONXP2459.html

Connect it to a switching Dc-Dc converter: https://www.amazon.com/dp/B06X1DPFQQ/

Now you have 5V, 30A available for your LEDs. Note, things will get HOT running at full power, you'll need a way to cool down the LEDs and the Dc-Dc converter.

Using that battery (75 watt hours), you should be able to power your LEDs (150watts) for about half an hour at full brightness.

Also, Id be very careful working with high capacity Lipo batteries, do your research and take precautions, they can be dangerous if not used correctly (shorting out leads/puncturing the case etc).

You may be able to find a better quality Dc-Dc converter, but make sure its a switching converter as they are much more energy efficient compared to a linear regulator Dc-Dc. 3 of these could also work: https://www.amazon.com/dp/B00VUHVX6W/

Edit: I just realize you need 4 (not 3) * 5V/10A, or 200W power.

Tons of room in mine (Ender 3 pro) on the fan side of the case. Depending on the converter of course. I'm using this one DROK 091016 DC-DC Buck Converter... https://www.amazon.ca/dp/B00VUHVX6W?ref=ppx_pop_mob_ap_share
For the extra current (so I can add other 12v goodies.)
I'm curious about these ones too cause they're tiny: Mini MP1584EN DC-DC Buck Converter Adjustable Power Step Down Module 24V to 12V 9V 5V 3V, 6 Pack https://www.amazon.ca/dp/B07CJ65YWH/ref=cm_sw_r_cp_apa_i_WwBCCb8VKXES6
But they have load limitations which require thinking. (Minimum load)

Assuming you define a smart charger as a charger capable of charging individual cells in a pack evenly and expeditiously I would say it's not required. OP can purchase a less expensive battery protection circuit ("BPC") or protected cells (18650s with the BPC built in) and lower his charge rate to a meager amount -- but even a 1A charge rate would be fine and charge the pack in ~4 hours. The inexpensive replacement for the smart charger would then be a constant current regulator. There are lots of versions of these, some with both a voltage and current display, and of course they can be dirt cheap when purchased from your friendly Chinese reseller.

I'm not saying your answer is wrong I'm just throwing it out there as another option.