Timeline for Do batteries have a delay when adjusting to a new load?
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
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| Apr 16, 2015 at 8:10 | vote | accept | MrPhooky | ||
| Sep 8, 2014 at 15:21 | comment | added | Russell McMahon♦ | .... (almost) any battery is an arcane brew of primary and secondary chemical reactions, internal resistances and load dependant impedances. If the voltage sagged as load was applied you should not be surprised. Nor if it did the opposite. Generation of gases and other products, temperature changes, ions migrating to and from places they should or shouldn't be, and more. || Run your ADC as fast as possible and log the voltage as and after load is applied. | Do you have an oscilloscope? | |
| Sep 8, 2014 at 14:37 | comment | added | Tut | You have not included a schematic or part number for your ADC. There may well be a set-up time (acquisition time) that is required after you switch the load. Could you do the conversion after the 25ms delay? | |
| Sep 8, 2014 at 14:21 | answer | added | horta | timeline score: 0 | |
| Sep 8, 2014 at 14:19 | comment | added | Russell McMahon♦ | .... An oscilloscope is an utterly essential tool for anyone trying to do anything serious with electronics - and you have crossed into "doing something serious". You can probably get an olde scope for GBP5 to to 10 and maybe free - or a not marvellous but useful one like this one on ebayfor 16 GBP - its from HK.OR you can use a PC audio input as a low feq scope - much on web about these. BUT .... | |
| Sep 8, 2014 at 14:11 | answer | added | Dave Tweed | timeline score: 1 | |
| Sep 8, 2014 at 14:10 | comment | added | Russell McMahon♦ | Not enough data, and your life test is liable to be invalid unless you can model the mechanisms liable to be involved well enough to allow for them. | BUT what you MUST do is measure the results with a time resolution that is relevant to what you are doing to the battery. Either use an ADC to sample the voltage at a rate such that successive readings show you clearly what is happening at the transition or observe the waveform with an oscilloscope. If you cannot do either of these you do not have the facilities necessary to do the sort of thing you are trying to do. .... | |
| Sep 8, 2014 at 14:01 | history | edited | MrPhooky | CC BY-SA 3.0 |
added 162 characters in body
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| Sep 8, 2014 at 14:00 | comment | added | MrPhooky | @ScottSeidman I can't really give it any longer before taking the measurement as this is part of an accelerated life test of the battery so it needs to simulate what it's target circuit does but do it quicker, otherwise the test could take years and years! | |
| Sep 8, 2014 at 13:52 | comment | added | Scott Seidman | Many things happen with a time constant attached. Wouldn't the easiest thing to do be to load for a longer time then take your reading? Perhaps there are resistive, capacitive, and inductive loads involved. | |
| Sep 8, 2014 at 13:41 | history | asked | MrPhooky | CC BY-SA 3.0 |