https://en.wikipedia.org/wiki/Supercapacitor <https://en.wikipedia.org/wiki/Supercapacitor>
If you operate the supercap at lower than max voltage and keep the temperature at close to 25C, the supercap will last as much as 20 years. No battery comes even close. You also need to look at lifecycle cost, not just cost of components. If you have to switch out the battery every few years, then the lifecycle cost for a battery will be much higher than supercaps. Regards, John > On May 19, 2016, at 2:12 AM, Lachlan Audas <laud...@gmail.com> wrote: > > Have a look at https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery > <https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery> > Depending on current/temperature they have much better life, up to 10,000 > cycles > and much better fire safety than LiPo, you may even be able to ship then on > flights. > > Supper caps, don't have a good life time, in fact they much worse then > Aluminum Capacitors > <http://www.digikey.com/product-search/en/capacitors/aluminum-capacitors/131081> > example the LGU1H103MELB 100,000uF has a life 3000 Hrs @ 105°C and much more > life at 25C > and it rated for -40C to +105C, and 4.09 amps ripple ratting, and cost $2 > in 5k > where as the BZ015A104ZSB 100mF (100,000uF) supper cat has only 1000 Hrs @ > 70°C and cost $6.000 in 5k > (Digikey prices) > So to get the Max life, use the step up switching reg to say 40V (remember > that energy on capt is = 1/2CV^2 ) > so double the voltage is 4 times the energy) then user a switch to step down > to you required voltage/current > So for max and life, only switch to the backup Caps when power fail's, that > way they remain cool, > give max life, and will give you good hold times. And of course all under > mic-controller control. > per my example circuit.. (example dose not have the control circuit, but can > be easily added ) > > Lachlan > > > > > > On Mon, May 16, 2016 at 4:52 PM, Dave Loomis <d...@lumieria.com > <mailto:d...@lumieria.com>> wrote: > > > You can sum it all up into this; The problem is completely solved by using > > a battery and having acpid installed. Except you need a way to completely > > disconnect power, from the BBB's input, for a single, or perhaps two corner > > cases that would otherwise require a hard reset. > > I love the no-nonsense mentality, and quality design behind this approach for > most use cases. But, for some high-reliability use cases like mine -- a > device permanently installed in a remote, client wall — batteries aren’t a > great fit. > > For long-term accessibility: Battery maintenance, even after years > of initial functionality, is extremely inconvenient or impossible. > For insurance reasons: The potential liability of installing > LiPo, which is known to have potential fire issues, into a client’s wall. > For shipping reasons: The added hassle of international > shipping of LiPo-based systems. > > > All these fancy high cost solutions are honestly ridiculous, and if you can > > just use an OTS UPS . . . > > Hardware cost is relative. The “high” cost (<$100) of a system > design is nothing, if it will potentially save me things like panicked client > calls, last-minute international plane tickets and high-pressure field > repairs. Those just aren’t fun. Obviously every project out there isn’t > heading to a NASA rover, but in some lines of work this kind of service is > expected when a high-end, mission-critical system goes down. In the end, if > I do my job right, the price is just passed on to the client who is willing > to pay a premium for a high reliability, maintenance-free product. > > I’d like to be able to deploy those systems based on the BBB, because I know > it, find the platform highly versatile, and a good match for the variety of > projects I take on. I think the PRUs especially make this a very unique > little SoC. > > Best, > ST > > > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com > <mailto:beagleboard%2bunsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/8A4F134B-E937-4958-8A25-E8BEDB02E6FC%40lumieria.com > > <https://groups.google.com/d/msgid/beagleboard/8A4F134B-E937-4958-8A25-E8BEDB02E6FC%40lumieria.com>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. > > > -- > For more options, visit http://beagleboard.org/discuss > <http://beagleboard.org/discuss> > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com > <mailto:beagleboard+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/CAMkt-MtdXLKP3VUTav_d_uGew4OAQfWT0iVSO9Zd6%2B5a0pYxUA%40mail.gmail.com > > <https://groups.google.com/d/msgid/beagleboard/CAMkt-MtdXLKP3VUTav_d_uGew4OAQfWT0iVSO9Zd6%2B5a0pYxUA%40mail.gmail.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/405D3ADC-57FB-49C2-BFFF-FA6597936E08%40gmail.com. For more options, visit https://groups.google.com/d/optout.
