These WS2812 leds don't allow you to control the individual brightness of each led, so you get approximately 60mA for each LED when it's powered on.
If you keep using these, you need to resort to power saving tricks in order to reduce your power consumption.
For example, you say you have 150 leds, so in your Arduino or whatever you use, you can separate them in 5 x 30 led groups.
Instead of lightning all 150 up, light up only 30 leds at a time... think of it as having 30 groups of 5 leds.
Send the data from your arduino to light up every 5th led in the strip, and for the others, send black... so they don't turn on.
Wait around 5 ms, then turn off all leds and send the data to turn on every 2nd led from each set of 5 leds . Wait 5 ms and do it again with every 3rd led from the 5 led groups.
This way, within 25ms, you have only 1 out of 5 leds lit up, each for 5ms, but the human eyes aren't that sensitive, so they'll basically see all the leds being lit but at lower brightness.
So now, your total power consumption is 30 leds x 60 mA = 1800mA or 1.8A
Let's say you have 8 rechargeable AA batteries in series, each 2500mAh in capacity, so you have 8x1.2v = 9.6v and 2.5Ah
A DC-DC converter can convert 9.6v to 5v at 2A (you need 1.8 but let's be safe and go for 2) at around 95% efficiency. 5v at 2A is 10 watts... assuming 95% efficiency, let's say 10.5 watts are gonna be taken by the dc-dc converter.
So the current taken from the battery pack will be 10.5w /9.6v = ~ 1.1A
You can look in a datasheet for batteries :
http://data.energizer.com/pdfs/hr6-2650_eu.pdfYou can see there on the Typical performance graph (green curve on bottom left drawing on page 1) that at 1.325A, the battery will get down to 1.1v in around 2 hours...
So even by turning on only 1 out of 5 leds at a time, you'll only get around 2 hours from a 8 pack of batteries.
18650 batteries will give you higher voltage and capacity, typically 3.7v..4.2v and 2500..3000 mAh, so you could have 4 in series for a total of ~ 16v or you could have 2 groups of 2 batteries in parallel for ~ 7..8v but at 5-6000 mAh if you picked a dc-dc converter that can't handle high voltages.
You can go further and make groups of 8 leds if it makes the program easier for you ( you turn leds on or off by seeing if a bit is set in a byte or not for example)