My take on time lapse power for Olympus : Custom external battery packs.

I was posting this as a reply in another thread. It occurred to me it may be better to start a new thread.

I have been obsessed with learning to do time lapse well. Battery life is one of the first major problems you run into, shooting mirrorless for time lapse. I considered a number of options, mostly based on using a usb power pack with an adapter made from the plug I scalp off a knockoff AC adapter. Alternatively, I was going to build custom packs with safe LiFePO4 cells, but that was going to be expensive. I hate the battery grips, and prefer my L brackets. Others had already done the usb battery pack solution, but it wasn't going to work for me with the battery grip adapter. I found a chap in Austria that is 3d printing OM-D and PEN batteries, and rigging them up with contacts and a standard lead with barrel connector. I ordered several, and while I waited for them to arrive, took a look at what else I might need.

I decided I should have a look at the Oly battery, and see if it is regulated or not, and what the voltages are when charged/discharged. I'm so glad I did. The Olympus batteries are simply 2 standard li-ion cells in a series arrangement, with no voltage regulation. So despite stating a voltage of 7.4-7.6V on the batteries, they are 8.1 volts or so when fully charged, and closer to 7 when depleted. That means it is possible to build a battery pack for Oly cameras, with any arrangement of 2 standard li-ion cells in series. No fancy electronics required. That put my notion of LiFePO4 packs out, since they are a lower voltage battery. If I used Li-ion, I would need no intermediate electronics to regulate the voltage.

I had some old unused laptops sitting around, as well as some barely used USB power packs. I gutted the laptop batteries, and the power packs, for the li-ion cells. Many modern li-ion batts are built with a single cell type, called 18650. They are in everything. After gutting these batteries I had on hand, I managed to build up 7 battery packs consisting of 4 18650 batteries. The packs with newer cells are giving me around 4500mAh capacity, while the really old laptop cells are more like 2000mAh each. I built a y connector so I can link multiple packs in parallel, in the event I want to keep a time lapse going for days, or longer(switching out packs every few days). I also built a Y adapter for the output, so I can run two cameras off the same pack/group of packs.

Here are the packs when almost completed. Sorry didnt take any shots during the build really. The tiny protection pcb is nestled under the wires there:

I laid everything out to take a pic before I started finishing the packs. You can see some packs, and a few bare cells. The two dummy batteries, as well as my parallel y connectors are there as well:

Here my packs are essentially done. They aren't shrink wrapped yet, as I wanted to test them with a few charge/discharge cycles before committing to the wrap.

Since it was all still theory on my part, I decided to start with my e-m5, which is beat up, has a dead evf, and has one foot in the grave. I removed the battery door by compressing the hinge pin with the little screw head that pokes out. I plugged in the dummy battery, and hooked up the battery pack. Well wouldn't you know it fired right up. I left it on for a few hours just shooting at the wall to see that it worked. No problems. Encouraged, I tried it on my E-M1. Works great. I had an e-pl5 on hand that is an xmas present for my cousin, so I tried it on that, and it worked great. I now also have an e-m5ii, and can report this works great on that too.

So it's absolutely possible to build simple packs for Olympus cameras. Some electronics skill is recommended. If you have none, the usb battery packs with selectable dc out may be the better option. If you do build packs, I recommend including protection pcb's in your design. The 18650 batteries mostly have individual protection on battery, but it's good to protect your pack as a whole with a pcb, so it isnt charged or discharged beyond capacity, which is much worse for lithium chemistry batteries than it can be for other types.

Where there's a will there's a way. It's not easy shooting time lapse as non canon/nikon/sony shooter. All the tools to make life easier are for those systems. But it can be done!

Here's my setup from yesterday morning. I was at the mouth of the Cuyahoga River, where it empties into Lake Erie. There is an old Coast Guard Station on one side, and the city on the other. I was set up to shoot the sun rising behind the city, and also to catch the morning light as it fell on the coast guard station. Both cameras are running off a pair of battery packs, linked in parallel. I was only there a bit over two hours, so both packs were unnecessary, but it was a proof of concept for me.

The two packs I took are made with my newer cells. These are 4500mAh packs, so 9000mAh total capacity. That's about the same as 7 factory batteries, if they provide the quoted capacity. I determined the capacity of my packs myself, so it's not based on anyone's quoted numbers.

Here's a shot of a dummy battery, in use in my E-M5ii:

And this shot is only somewhat related. I prefer hardware intervalometers over the in camera time lapse feature. I picked up these Desmond cable clamps to secure the connector over long term shots, and they work a treat. You can also see I had to notch my L plate to allow the cable to fit. Feel free to cringe at the sliced off rubber connector cover on my beat up old E-M5:

Well I hope maybe that helps or inspires someone thinking about getting into time lapse. It can be done, one way or another, and well, with m4/3.