Powering Sound Devices Mix-Pre 10 II

[casper2000]

Hey there, I have Sound Devices Mix-Pre 10 II and I have problem powering it.
I know I can use a plug to the power but I need to record outside without wall socket.
Another option is AA batteries but 8 AA's with 2100mAh will last just for less then an hour
which lead me to conclusion that L-Mount for Sony like batteries will not last any longer considering it's even less mAh than 16.800mAh (8 AA's)
Another option that was on smaller Mix-Pre was power banks but it doesn't work at all on this one (meaning it won't power it at all)
I need it to work for 12 hours with like one max. two power switches.
Any ideas?

[sonics]

Welcome to the SOS forum!

If you use the SmallRig 6700mAh battery packs you should get about eight hours from one of those. You'll need the Hirose DC cable.

An example (using the smaller 3400mAh pack) can be seen here:
https://youtu.be/a0yqgOGtK5A

[casper2000]

Thanks for the SmallRig 6700mAh advice.
I have one more question, any ideas why the AA's last just for an hour?
I don't think it's neither right or safe that over 16k of mAh last such a short amount of time.
Is it something wrong with the settings on MixPre?
I have it on Battery Type - NiMH, Ext Power NiMH, should I set it somewhat else?
The batteries are the Eneloop's 2100mAh, using 8 of them

[James Perrett]

Your capacity calculations are a bit off. When you add multiple cells in series you don't add up the AH. So a string of 8x2100mAH cells will still only give you 2100mAH, even though there are 8 in series. However, 8 cells will give you 8 x the watt hours (20.16WH as opposed to 2.52WH) because the WH calculation takes voltage into account.

One thing to check is that the cells are balanced - that is that they hold the same charge. Do you have a charger that charges the cells individually or does your charger charge them as a string of cells. If you only ever charge them as a string it is possible that one or more cells may not be fully charged when the charger switches off or switches to trickle charge mode. This can limit the capacity of the whole pack to that of the weakest cell.

I've seen suggestions elsewhere that 2500mAH cells should give you 2.5 hours recording time with phantom powered mics connected but it also depends on screen brightness and possibly other settings.

[Hugh Robjohns]

I'd treat the internal AA cells as a battery backup, and run the unit either from a pair of L-mount batteries on the optional adapter plate, or use something like an Audioroot smart Lithium battery pack or an NP1 etc connected via the Hirose port. That approach will easily give you 6-8 hours or more, and the internal batteries will allow hot-swapping of the L-mount or Hirose-connected battery pack.

If you're in the UK, have a conversation with the nice people at Pink Noise who will be able to advise on the most practical and affordable options.

If you're in the US or elsewhere, try and find a supplier of equipment to professional sound recordists — B&H in the US, perhaps? — who can advise similarly.