NP-F Batteries for the Zoom F8

Following on from my previous post about powering a Zoom F8 I decided I did want a more serious solution than the USB step-up adapter and end-up with a different kind of adapter. This time I tried a Hawk Woods DV-SQNR which converts Sony NP-F style (aka L-mount) batteries to a 12V Hirose connector.

The SQNR has a maximum output of 24W, so should easily provide enough power for the Zoom in all situations.

Why NP-F

The obvious solution to a better power source would have been a (nominal) 12V battery from Tracer or Talentcell. Of these two the Tracers are significantly more expensive, but it was hard to know how much of the extra expense is justified.

In favour of NP-F batteries:

  1. While the adapter is expensive (£70), it does give access to a wide range of affordable batteries. Compared to the 8Ah Tracer option it leaves £110 to spend on batteries which could buy a lot of 6600mAh (roughly 4Ah @ 12V) batteries from small brands.
  2. The pricing on the Tracer batteries strongly pushes you towards a single 8Ah battery (£180) vs having two 4Ah batteries (£240). That means you can’t just take a small battery for a day when you know you won’t need huge amounts of power, and it means all your power eggs are in one basket.
  3. NP-F batteries have become a bit of a standard for video equipment such as monitors, external recorders and lights. I already own a Manfrotto Lykos LED light I use for portable setups and that takes NP-F batteries natively. Using a single battery type for both has some advantages as I can maintain a general pool of power for whatever’s needed.

The contenders

There are a lot of NP-F batteries about with a range of claimed capacities and a range of prices. I bought a few to see how they compared.

KYTD

This was the cheapest battery I tried at £23 and a claimed capacity of 7800mAh.

Two interesting things about this battery compared to other cheap batteries. Firstly, it features a built-in capacity checker to show roughly how much power is remaining. This is particularly useful for use with the SQNR adapter which doesn’t feature any level indicator. Secondly, the battery can be charged directly from a USB connection.

Annsmann

I’ve heard good things about Annsmann NiMH AA batteries so thought this was worth a go. The battery is a little more expensive at £31[1]. It’s a completely plain affair with no tricks. The lack of an on-board capacity check makes this more useful for the Lykos than the Hawk Woods adapter. They get credit for a modest/realistic claim of 6600mAh.

Ex-Pro

Ex-Pro make loads of battery products and have a range of NP-F batteries. This is the biggest in the range, an 8-cell affair with a claimed capacity of 10400mAh. This works out to cells with an individual capacity of 2600mAh which is on the higher side, but the interesting thing about this model is it uses Samsung cells so should be a reliable number. This seems to be the cheapest way to get a battery based on named-brand cells.

As an aside, they also make a 8-cell version eith their own-brand cells which makes a realistic claim of 8800mAh, but also a 6-cell version with the same claimed capacity which implies 2900mAh cells. I’m a bit skeptical about the 2nd one.

This battery also includes a built-in capacity checker.

Runtime tests

The easiest way for me to test these is just to charge them fully and then run them down using the Lykos light. Manfrotto claim a 6600mAh Sony battery lasts 80 minutes so it’s not too slow a test to run. We can use this performance level as a very rough way of estimating real battery capacity, i.e. every minute of Lykos runtime is 82.5mAh capacity at the batteries native voltage, or 44.55mAh at 12V[2]. This assumes the Sony battery is exactly 6600mAh and the runtime estimate from Manfrotto is accurate. Apply a large pinch of salt.

For my test, the light was set to the daylight extreme and full power.

Battery

Claimed capacity (mAh)

Price (£)

Runtime (min)

Runtime per £ (min)

Est. capacity (mAh @ 7.2V)

Est. capacity (mAh @ 12V)

KYTD

7800

23

55

2.4

4500

2450

Annsmann

6600

35

93

2.6

7700

4100

Ex-Pro - Samsung cell

10400

49

138

2.8

11400

6100

The Lykos light does not run the battery down to exhaustion and in fact it will turn off the actual LEDs at low-power but keep the control interface powered-up. With the KYTD battery the light switched off while the on-board checker was still reporting 50% capacity. The on-board battery gauge on the Lykos proved not to be not much help, only showing 100%, 50%, 0% levels with uneven times between those states.

It’s a small data set, but does imply that there’s no such thing as a bargain, and spending more gets more capacity and more capacity-per-pound. There are more expensive batteries than the Ex-Pro but you’re mostly paying for name, perceived build-quality, regulatory documentation etc.

Real world usage

I’ve used the SQNR adapter twice now for real-world field recordings and it worked fine. The bigger project was a 7-channel recording (all condensers) which took place over 4.5 hours (including setup and packing time). I made no effort to save power during the day and once the Zoom was turned on I left it on. By the end of the recording the on-board checker on the Ex-Pro was showing 50% capacity and my charger reported 60% capacity remaining.

The biggest issue with the SQNR is that it will not power-up the Zoom F8 by itself. So, you must have internal batteries or a barrel-input source (such as the USB adapter I used before) to get the F8 to turn on. Once on, the F8 will prefer the SQNR over the internal batteries. It will prefer to use the barrel input over the SQNR-on-Hirose, but you can safely unplug.

I don’t know if this is a property of the F8 or the SQNR but it is something to be aware of. If you leave the battery sled at home, or have flat batteries, and don’t have a barrel-input source you’re not getting anything done.

Good decision / bad decision

So, does this mean the SQNR was a good choice? Not sure.

The cost benefits haven’t worked out as I hoped, given the idea of very cheap, big NP-F batteries is a mirage. The ~6Ah combination of SQNR and Ex-Pro is cost competitive with the Tracer batteries, but it’s not a world apart. It improves if you’re in a situation you’d want multiple big NP-F batteries just for audio recording. The Talentcells are a lot cheaper and if less impressive looking may well be just as good.

The inability for the SQNR to power-up the F8 by itself isn’t great, even if I expect to always have the sled and USB adapter with me, it’s just another thing that could go wrong. If that’s a property of the SQNR and not the F8 Hirose input it would tilt me towards the 12V batteries.

I’ve also found that when I need to do something quickly on the F8 I tend to reach for the USB adapter and not the SQNR. It’s just easier to use. I don’t leave a NP-F battery mounted to the adapter when not in use[3], and I don’t leave the battery sled in the F8. All of that assembly is a lot more faff compared to plugging to the USB adapter to a USB charger or power-bank.

So in conclusion, the SQNR is fine but it’s not absolutely compelling.

  1. Amazon price, I’ve seen it for £50 elsewhere [Back]
  2. Assuming 90% SQNR conversion efficiency [Back]
  3. Although informal testing suggests it doesn’t drain the battery significantly [Back]