[sdiy] Outside Synth DIY topics but could be of some interest..

[Brian Willoughby]

On Dec 22, 2021, at 13:53, Ben Stuyts <ben at stuyts.nl> wrote:
> On 22 Dec 2021, at 22:31, Brian Willoughby <brianw at audiobanshee.com> wrote:
>> There is at least one company making battery boosters. These are extremely thin brackets that fit around each standard size of battery, and boost the voltage from dying batteries to normal. I'm not sure what kind of supply they use, but they work with most "dead" batteries. A serious advantage is that they work with devices (such as remote controls) where external power jacks are not available.
> 
> If you are referring to the Batteriser, those have been thoroughly debunked. See https://duckduckgo.com/?q=batteriser+debunk

Well, I own a set of four of the Batteriser in AA size, and this debunking hasn't stopped them from working!

Either I missed the claim that 80% of the power of a battery remains after it's "dead" ... or I simply never believed it. I would expect that far less than 50% remains, and probably usually less than that.

Hackaday is a great site for fun, but they really are amateur. The "debunking" assumes that the device(s) they tested represent all devices, and that's far from the case. In my experience, devices vary *widely* in the minimum voltage they need from a battery in order to operate.

The most annoying variance is that some devices require a minimum voltage that's greater than rechargeable batteries. Many of the "advanced" lithium or rechargeable batteries that I buy are rated at 1.2 V on the case, where basic batteries are rated at 1.5 V. I have several devices that will not work at all with the 1.2 V batteries, so I either have to use basic 1.5 V batteries or use the Batteriser to boost the voltage.

I think that a fair "debunking" would need to survey far more real-world devices than Hackaday tested. I suspect that their example is not in the majority. That said, the "80% of your dead battery's original power is still available" is not mathematically true, except perhaps in one product design out of millions. Regardless of whether there's 80% remaining, or just a measly extra little bit remaining, the Batteriser does turn a non-working battery into a working battery.

Even though they "work" ... I wouldn't recommend the Batteriser. The biggest reason is that they fit too tightly into a battery compartment and are almost impossible to insert, much less remove. They are incredibly thin, but the whole circuit fits on the + side of the battery, adding a bit too much length for many devices. You can force them in, but it's not a good idea.

However, getting back to the OP: The only reason I brought this up was for the idea of using an automatically-self-adjusting switching supply design to extract energy from batteries with insufficient voltage. I'm thinking that you could do a lot if you circumvent the sizing constraints of the Batteriser and used a fancy inductive voltage booster that can boost more than double voltage.

Brian