insomniac

If you go back to my post from Aug 21; that shows my 3 battery 18350 solution for the Canon V1.

Yeah, the charging circuit on this battery is not safe at all... My custom solution earlier in this thread is exponentially safer. Can't say I'm surprised #china. So let this be a warning of what not to do or you could start a fire. AKA: Only buy batteries from reputable sources; and if it's hard to find something there's likely a good reason for that. These batteries are immediately getting disposed of. But the "silver lining" is these things did start "rebooting" on their own when max temp was achieved.

Not sure if I love this solution so far, the battery is getting pretty hot during the charging process. It would probably be ideal to run two batteries at 7.2V for this solution; but that requires "work." I'll keep an eye on the max temp of the battery with a thermal camera and report back.

USB-C delivers 5V, I believe it just ups the V and drops the amperage using a micro boost converter. Update: Just confirmed (see below) **I'll keep this thread updated in case my camera starts on fire; you never really know with some of this stuff....

The last photo shows the 1x 18650 battery in the housing (green thing on left) with it plugged into camera and the camera charging. This battery has a built in bi-directional USB-C port (most batteries this size only have support for charging the battery, not charging a device - but this one does). As you can see in the upper right screen shot, it's charging my battery via USB-C. If you have 5cm that is enough; you could fit in an 18500 battery (the 500 part representing 50.0mm or 5cm). Scroll back to see my custom 18500 battery pack for that solution.

I'm super happy; while building the custom battery for my wives housing I starting thinking if I could do something similar in my Nauticam Sony A1 housing. My solution is exponentially easier, and anyone with a similar housing can do this with no electronic knowledge required! A bit of background, I noticed you can buy 21700 batteries with bi-directional USB-C circuit charging built into the battery itself; I was wondering if something might exist for 18650's as well; and it took some digging but I found some (and I was order #1001 AKA#1) so I don't think anyone else knows about them: LBF BatteryButton Top Protected 18650 3500mAh Flashlight Battery Typ...【Battery Specification】Battery type: 18650 Button Top PCB Proctected, Capacity: 3500mAh, Wh Rating: 12.95Wh, Voltage: 3.7V, Size: 18.5*70.5mm(0.72*2.77 inches), Feature: Type-C Input/Output, Quantity: That combined with this from Amazon: https://www.amazon.com/dp/B0F8HW858S And it fits perfect in the housing. Just put a little electrical tape over the positive/negative ends for safety; plug it in and you are good to go. If my math is right this should add about 70% capacity to an existing Sony battery (aka 1-2 more dives). Here it is installed:

It can also do 4k 60p unlike the old model.

We really should move this thread to a new forum regarding custom battery solutions, but oh well here we are... This might work (as the 16mm isn't discontinued yet). And actually they still might be able to make the M14 one as the description says they are manufactured on demand. It would be "clunkly-ish" but you could maybe do this: NauticamM16 to M14 Step-Down Adapter ~for Electrical BulkheadAllows for the use of M14 electrical bulkheads in M16 housing sockets.and this NauticamM16 Offset Connector with Dual Activation Vacuum Valve ~C...This dual-activation offset vacuum valve supports creating a vacuum with either the hand pump or via a low pressure inflator. The offset allows the bulkhead to be used for another purpose such as an e

If you want to take the risk and forgo the vacuum (scary), you could for sure do it. I would recommend keeping your battery; and just charging it through the USB port. The RX100 can charge and be powered on at the same time. Some camera's only charge when off (but still, just turn off the camera between dives and it will charge up). The Canon actually runs off my custom battery pack (when turned on, and my pack has juice); and when the camera is off it charges the camera battery. You really don't want to use a dummy battery unless you have no other choice; as you are giving up additional capacity and redundancy.

I also just confirmed I can build a 2x 18500 battery pack to likely fit in most full frame camera housings (I have a Sony A1). It would add 4800mAh of battery life (enough to get you through a full day considering the full frame batteries (for Sony, and likely others) are already pretty descent). That said, I use a flash trigger in my housing, so they are too big to fit with that. But I am now curious to see if I can come up with a solution that will work with my camera (down the rabbit hole I go).

I just finished up the 18500 battery pack, it fits amazingly well and has an insane 9600mAh of power (enough to last 8+ hours)... I made this one with a slightly fancier board, that shows how much battery is left (and when charging how full the battery is).

For the Sony, I bought a GoPro 3 housing many many years ago that had an external battery holder for 1x 18650 battery (at the time it was like over $500, and it came with a custom aluminum gopro case that I didn't even need). Anyways, I cut the wire on the battery holder and then soldered a USB cable to the other side. Before connecting the wires I ran it through a Nauticam Socket Extension and then I just made sure my wires were split up pretty good and fully inside the socket extension and epoxied it inside. This worked amazing for about 6 years, and then I started getting an insanely small vacuum leak (only on land, stayed sealed when testing with some toilet paper in the housing and the housing in a 5 gallon bucket of water). I never got a drop of water on the toilet paper, but I ended up just using a Dremel to remove about 2cm of epoxy and re-epoxied it and hasn't been a problem since. It's a super simple cable that could have any tip (Micro USB, USB-C, etc), and because it's magnetic it makes it super easy to install in the housing (there's a million on Amazon, here's an example), mine has a little light that comes on so you know it's connected. The battery has an on / off switch which can be annoying but it's been so nice. You get an entire day without having to open the housing and swap batteries. Here's some pics of that...

I went ahead and ordered this camera and housing for my wife (who currently shoots an RX100 VII). If all goes well; expect to see that in the classifieds section soon. One big "deal breaker" for us is having to swap batteries every dive. These compact camera's never have that great of battery capacity. On the RX100 VII; Nauticam has an extra entrance port (meant for HDMI); but I use that to run a custom 18650 battery enclosure I have on the outside of the housing; that allows her to shoot at least 3-4 dives without needing to open the housing / swap batteries. Because the NA-CV1 doesn't have an HDMI port; the only option was to forgo the vacuum valve (deal breaker); or utilize the space where the flash trigger adapter + Nauticam flash trigger (since she is video only, this was a viable option). I am happy to report back that you can easily fit 4x 18350 batteries in that spot, and I even managed to get 4x 18500 batteries to fit. All that to say, it does take some specialty skills to build a custom lithium battery pack; but in today's day and age that's not too hard to obtain. I built a couple packs with BMS, USB-C Bidirectional Power Delivery/Charging, and even a thermal sensor on the pack to shut it down if it exceeds a certain temp (highly unlikely, but nice for safety). Just for reference; I did a test video shoot with the smaller 4x 18350 batteries and it recorded for 6 hours straight and then I ran out of memory card space (vs. battery). And I love the fact that this fits inside the housing vs externally as it's much more streamlined. I'll bet you that you could even fit a flash trigger in the space along with 2x batteries if you used something like the UWTechnics flash trigger (vs. the bulky Nauticam one). Anyways, I'll share feedback and more pictures when I have the time. For now here's the progress shots of one of the first battery packs I made with 18350 batteries.

Too funny, I have the same exact strap wrench. In this case, I wasn't able to get it to grip well with the small surface area. The Irwin clamp happened to work easily and didn't damage the surface. Just wanted to give people a heads up of another potential tool to use. After breaking my last lens with the combination use of a vice clamp and induction stovetop; I figured I'de share something that worked this time around. But I agree, those strap wrenches are great!

A strap wrench would have been virtually impossible to use on this filter holder, they can work on the actual lenses themselves though...