It's always good to put in provision for new discoveries i.e for new knowledge that maybe a cap is found which greatly enhances these Lithium phosphate batteries?nige2000 wrote:sure is easier to have the pads and not use them than the other way roundjkeny wrote:
You may be right, Nige that capacitors only slow down the current delivery in battery operation but in designing a pcb, I would consider it wise to include pads for them.
i used these for bypass on the prototype
http://ie.farnell.com/wima/smdtc04220tb ... dp/1890111
id be inclined to test something along these lines
these film type caps dont seem to have the same slowing effect that alot of caps have with the batteries
Yea, traditional electrolytic bypass capacitors should not be used here - I doubt they have the speed necessary throughout the frequency range. The problem of current delivery in power amps is that we need gobs of current (I've read somewhere that it is quite a bit more than is traditionally considered) for LF signal elements & very fast but smaller current delivery for HF signal elements. Considering that music signals are a simultaneous combination of both LF & HF signals this becomes a big ask & batteries seem to answer this requirement excellently.
From experience with them, I formed the opinion that lifepo4 batteries are like perfect large capacitors - they don't need to be constantly recharged in between delivery of large pulses of LF current (I believe this is the problem with most PSes - there is a certain finite recovery time for the PS caps ) & they are very fast in both LF & HF current delivery. So it's hard to know what capacitors could be used with them as they don't seem to have a weak area that needs attention.
Nige, apart from no detriment, did you notice any benefit with using these film caps (I can't see any esr figure sin their datasheet)?
