I got a couple of there HyperGear batteries for a song and have been using them with great success. Around 7 hours on a single charge and the red/black version can be had for $23 on Amazon.
https://www.amazon.com/dp/B01KYUDAN4?ref_=pfb_29fjld6id8h4dnhiae7j64kjk55k&tag=hydfbook0e-20&ascsubtag=pfb-P01-V01-O5-T1-HI-4DCJUB&th=1
Great battery. Got about 7 1/2 hours. 2 channel. Lights and LED’s down to 1. Nice small size. Using it with a 1 foot cable. Very happy.
Just got one today and love the size! Got the right angle c > c posted a while back and they show green on the mp6. I have an Anker PowerCore+ 26800 which is great but it's big, heavy and overkill except for once or twice a year.
Has anyone run 4 channel with these? Not way for me to really test that at home. I don't have 2 sets of mics so any 4 channel will be mics on 1&2 and sbd on 3&4.
Ran some test with this yesterday recording the stereo in my office. 2 channel phantom, bluetooth off, lights on 3. I got 8 hrs and 50 minutes!
I did have an issue though. I have the 4 sled AA in as backup. When the usb battery died it did not automatically switch to the AA's. I did not see it happen but when I came back in to check the mp6 had an error on the screen that said "stream access error". Behind that there was another error about usb but I couldn't see what it said. I should have taken a picture. I charged the usb battery overnight and this morning if I pull the cable out it switches to AA just like it should. So not sure what happened or why. Card is a 32gb SD branded card and was far from full.
edit: testing again to see if it does it again. should know in about 7 hours........
Tested again and this time I was sitting here when it happened. Seems when the battery starts to get really low (1 bar) but not dead the power requirement is not enough to power the mixpre. The two errors are as follows:
USB Power Source is not compliant
Use battery power instead?
OK Quitbefore I could hit ok I got this:
SD Warning
Stream access Error
OKWhen I hit ok it goes back to the usb error, hitting ok does not switch to battery as the stream error comes up again. Then it shut off.
This happened at 8 hr's and 46 minutes and the bar on the battery at one which indicates less than 25% power remaining. So again it seems that when the battery was super low it couldn't provide enough wattage. That makes sense but not sure why that kicks up the "Stream access error".
Wave file wrote correctly till it cut off at the end. The very end it "flat lines" as the battery power drained. Battery light was green the entire time.
If this isn't going to cause problems I'm fine using it and just remembering to never push it past 8 hr's which I never need anyway.
I have not tested my Anker PowerCore+ 26800 to see if the same thing happens when it gets too low. I plan to tomorrow.