Unfortunately, battery manufacturers often give very optimistic specs, too. For any application other than very simple, non-critical ones, I've always had to test batteries in the actual application to be sure what performance i was going to get. Anything critical can state that it needs quality batteries and give a short list of acceptable ones. Sean On Tue, Nov 2, 2010 at 5:48 PM, Stephen R Phillips wrote: > Depends on the battery type. With a primary cell you dissipate some of th= e energy in the cell as well. =A0Lithium thionylchloride batteries for exam= ple do not like it one bit. However the standard CR2032 is manganese dioxid= e instead so its internal impedance isn't as severely impaired by large cur= rent draws. > > I suggest you ignore TI's claims. The main reason why is you should alway= s go by the battery manufacturers specs. Since you cannot test the batterie= s without discharging them and possibly damaging them in the process you ca= nnot test and sort for which battery will fail. Bottom line is the batterie= s are made to a spec and the manufacturer can change the battery beneath th= at spec any time as long as it meets the spec. This happens with rechargeab= le lithium ion batteries all the time. Although less likely with a lithium = primary cell it's a possibility and your design may not work any longer. > > Stephen > > --- On Tue, 11/2/10, Mark Rages wrote: > >> From: Mark Rages >> Subject: [EE] Coin cells and peak current draw >> To: "Microcontroller discussion list - Public." >> Date: Tuesday, November 2, 2010, 11:43 AM >> (Adding tag) >> >> I have often heard that drawing pulses of more than about >> 15 mA from a >> CR2032 coin cell will permanently degrade its capacity. >> >> But TI has done the experiment and claims up to 30 mA with >> minimal >> change in battery capacity: >> >> http://focus.ti.com/general/docs/lit/getliterature.tsp?literatureNumber= =3Dswra349 >> >> Battery internal resistance is still the enemy, though. =A0A >> big >> capacitor can help hold up the voltage during the current >> peak. >> >> Looks like all testing was at room temperature too, which >> seems like a >> big limitation. =A0Also interesting is the difference >> between claimed >> and actual performance. (spoiler: Sony good, noname bad). >> >> Regards, >> Mark >> markrages@gmail >> -- >> Mark Rages, Engineer >> Midwest Telecine LLC >> markrages@midwesttelecine.com >> >> >> >> -- >> Mark Rages, Engineer >> Midwest Telecine LLC >> markrages@midwesttelecine.com >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > > > > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .