One big problem with IR remotes is as the batteries get weaker, contact resistance becomes a problem. Even if it's only a 2x lifetime, I want to use them in an IR remote control.
Tray-style battery compartments should be no problem.īut if they really work like they ought to work, I want some. You can't do that when wrapped around a single cell.Īnother "too good too be true" is if you have a "pipe"-style battery compartment and the batteries leak, it could be harder to extract them. I think the Joule Thief design puts its power switch before the boost converter. It would also have to know when the device is turned off. The form factor is the tricky part, because you need to fit a boost coil and a capacitor in there somehow, and they might have to custom-wind the coil to make it fit, making it more costly to manufacture than it would be with off-the-shelf parts. It'll work until it can't provide enough current for the device that it's powering. To raise the volts, you have to lower the amps. For the price mentioned in the article I will buy a few sets of these as soon as they hit the market.Īnd there's math behind it, too. A device like this, with an appropriate capacitor for peak current (which most of the devices already have internally), would cut down the number of batteries I use per year significantly.
I AM an engineer and understand that "there ain't no such thing as a free lunch" but most of the devices are low average current drain with intermittent higher current peaks (a sensor that transmits a new reading every couple of minutes). The devices use between 2 and 4 cells each, and I have to change batteries in most of them between one and two times per year. However, virtually all of the devices I have quit working when the cell voltage gets below about 1.34 volts. I fresh cell will be a bit over 1.5 volts and good design SHOULD permit operation down to about 1 volt per cell. I have a number of wireless devices ( remote thermometers, rain gauges, etc ) that use AA and AAA cells and I have tracked the failure voltage of most of them for several years. So what actually gains? Devices that are maldesigned enough to brown out with even modest voltage droop but also sufficiently low drain that the draw of the converter will remain within the battery's 'best-case' discharge cycle but not so low drain that the (modest but nonzero) losses in the DC-DC converter increase the overall drain by a substantial amount. Devices with very high power draw might see a benefit because they will drive the battery to slump most quickly(and, according to the discharge curves for most alkalines, very high currents will cause substantial slump well before the capacity is exhausted) but the DC-DC converter will need even higher discharge current in order to keep power output constant as voltage drops, which will exacerbate the voltage slump, and likely hit the wall where the effective internal resistance of the battery is high enough that it simply won't deliver any more current. Anything with very low power draw will also see very limited benefit, because even badly depleted batteries slump as discharge current increases. This seems to constrain the useful market for this product to a very narrow, rather weird, niche: Anything that already tolerates voltage droop well will see very limited benefit. If you do, you'll be flooded with unhappy and confused customers and probably lots of expensive returns. Especially because NiCd and NiMH rechargeables are only good for ~1.2v(maybe 1.3-1.4 hot off the charger, for a few moments), alkalines for ~1.5 but with well known droop as they are exhausted or if discharge current is too high and lithium primary cells in AAA or AA packages are up around 1.7, with less droop you simply can't build a consumer widget that is too picky about battery voltage. However, there's a problem here: Most even vaguely well designed widgets already tolerate some amount of voltage variation. You(for some reason) have an antique filament-bulb flashlight and you don't want it to spend the last chunk of its life putting out relatively useless IR because the filament temperature is too low for visible light? A DC-DC converter will fully flatten the batteries faster(because of its own losses, and because current draw has to increase as voltage droops in order to maintain the same power output) but at least the entire lifespan will be spent putting out usable light. You want a blue or white LED in your flashlight without resorting to an expensive cell chemistry or 3ish alkalines in series? Well, DC-DC converter it is.
Ok, DC-DC converters do have a legitimate place in battery powered systems.