Oculus: The Case “For” (and “Against”) Lithium Polymer Batteries
One of the first accessories many of us acquire for the Oculus series of VR headsets is a quality set of rechargeable AA batteries for the Oculus Touch controllers. As with every other product out there, you have a plethora of choices in the renewable energy battery department. Do lithium polymer batteries make sense for you?
Among the VR Elite, the Eneloop series rechargable batteries are the accepted choice and are always recommended when a newbie comes bearing questions about batteries. And why not? They are quality products that use nickel metal hydride (NiMH) as the energy storage — a widely used, long tested method of delivery; one used by almost all rechargeable batteries you’re likely to find. They are easy to get and relatively cheap (8 for under $30).
What Is Lithium Polymer?
Many people have never even heard of lithium polymer batteries — I didn’t until recently — but I thought it was worth bringing them to the table for those that aren’t familiar with them.
Note: We’re not going to get technical in this article; we’ll keep it straight for the layman.
From Wikipedia: (this is as tech as we’re going to get here)
A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated as LiPo, LIP, Li-poly, lithium-poly and others), is a rechargeable battery of lithium-ion technology using a polymer electrolyte instead of a liquid electrolyte. High conductivity semisolid (gel) polymers form this electrolyte. These batteries provide higher specific energy than other lithium battery types and are used in applications where weight is a critical feature, like mobile devices and radio-controlled aircraft.
The keen eye probably picked up the key phrase: “… where weight is a critical feature …”
Batteries, Weight and Oculus Touch
The obvious advantage of “lighter batteries” is that it makes whatever they are in … lighter. This is ideal for applications where the weight can degrade performance or life-cycle of the use — such as remote controlled cars, drones or other devices where weight can become an object of discomfort (portable devices of any kind that people carry on their persons).
This naturally sounds great for a controller (two, actually) that you may be holding for long periods of time and flailing around in the air while playing Beat Saber.
Anything that can make it more comfortable to stay in VR longer? That’s a winner.
Comfort isn’t the only advantage. Many people complain about a problem known as “compression disconnect”; where high energy movement causes the weight of the battery to compress against the spring (the negative end) and cause a momentary disconnect of the battery (the positive end) to the controller which naturally sends your in game controller spinning off into space.
So much for an SS rating on your Expert+ map.
This has lead to many “hacks” like replacing/augmenting the spring, wrapping batteries in rubber bands (to keep them in place) and even more drastic mods.
It should go without saying that a lighter battery should improve or even eliminate this issue.
Those are two checks in the “plus” column for using li-poly batteries in your Oculus Touch and those are compelling.
Battery Life, Longevity and Discharge Rate
All three are considerations for selecting the right battery for your application. How long do they last? How many times can they be recharged? If they are sitting off the charger, will they discharge on their own?
How long do they last compared to alkaline or NiMH? Oddly, this was difficult to obtain information on — other than my non-technical “gut” feeling during my own use.
Most sources say that li-poly batteries will last longer than NiMH and my own non-scientific use agree. That has to mean that the run time is significantly longer to be noticed in this use case. I know this because my Mamut grips cover the battery compartment and changing the batteries is a real chore.
So, put battery life in the “plus” column for now.
Longevity is a slippery slope. Bear with me; my research shows a great disparity in this information and it can be a bit confusing.
Over time, rechargeable batteries lose “full capacity” charge. Doesn’t matter if it is NiMH, lithium polymer — it is the nature of the beast.
Let’s say you charge a battery every day (because you are a VR playing machine), and it loses .25% capacity each charge (these are hypothetical numbers — for the easy of concept understanding) that would mean after 400 charges, that battery would need to be replaced. But it also means that after each charge it doesn’t last as long, meaning you have to recharge it more frequently. After 200 charges, it would be down to 50% capacity, meaning you are having to replace it 2x more frequently.
But if the battery was able to hold total capacity longer, you would have to recharge them less and get more usage between replacements, right?
This could be called “charges vs usage” and this is important.
According to my research, li-poly batteries retain full charging capabilities longer than other lithium-ion battery types. This means that you don’t have to recharge them as often over the lifespan of battery ownership.
More usage out of fewer charges.
NiMH batteries often boast being chargeable 1000+ times (or more) which makes them seem like a clear winner over li-poly which run into the 300–400 charges range.
But once you factor in the “charges vs usage” factor? You’re probably pretty close in terms of overall lifespan of the battery.
But consider … similar lifespan with less times you have to change the battery out of your controller.
Throw longevity in the “plus” column.
What about discharge rate? Why should you care?
When rechargables sit idle, they start to lose energy. Alkaline batteries at room temperature (hotter environments cause more drain) will discharge at about 2% per year. No wonder they are so popular.
Those coveted Eneloops and other NiMH batteries self-discharge a few percent per day (whoa) however cold temperatures slow that down (pop them in the freezer and you can get 10% per month discharge). Hence the “batteries in the freezer” lore — which makes negligible difference in alkaline, by the way.
Where does li-poly weigh in? My research shows 2–5% per month.
That’s great — you can be relatively sure when you grab those li-poly batteries out of the drawer you can be reliant that there is life in them. When I used NiMH rechargeable batteries, I would often find (and install) dead batteries.
Discharge rate — in the “plus” column.
The Cases Against Lithium-Polymer Batteries
It isn’t all wine and roses — although I can say over time, I’ve grown to be totally cool with these issues.
They Die Instantly
When they die, they die. As they said in The Warriors; “No papers, no parley”.
Your controller will simply shut off. No ability to play just ONE more round of Space Pirate Trainer.
No Battery Indicators
This is probably something to do with the Oculus Quest itself, but there are no indicators of battery discharge or level of charge.
They are 100% until they die. Then they are 0%.
For a lot of people, this is probably the primary reason they would avoid lithium polymer (along with the price).
As I said, I’ve gotten used to it. I don’t mind the indicator not being accurate (people have been complaining about Quest Touch battery indicators being wrong since the beginning anyway) but most importantly, I’m okay with them dying suddenly. Why?
Because they are at full capacity until they die.
Why does that matter? Because as the batteries start to die, I see issues in tracking and performance. I’d rather have full performance until the battery goes kaput.
Let’s cut to the chase. They cost more. It is just that simple. How much more? Note: we’re talking U.S. Dollars here.
Eneloops are 8 for $30 (or $3.75 each). If you need a charger, you can expect to pay about $5 per battery which would include a charger.
Lithium polymer cost about $10 per battery (which includes a charger).
That makes li-poly twice as expensive as Eneloops. Suddenly all the pluses seem to disappear, right?
That depends on you.
What Is The Bottom Line?
As with everything else, the bottom line is what is more important to you?
Price or convenience?
With a couple of “minuses” checks, li-poly batteries solve some issues with Touch controllers, make your overall experience better with less changing of batteries and lighter weight — but they instantly die and have no indications of level.
Is it worth it? I think so. I use them and I love them. I wouldn’t go back to NiMH or alkaline.
Weigh the convenience factor versus the cost. Make the call that is right for you.