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  1. T

    Best way to make a 13Ah min up to 10c discharge 70 cell batt

    I was hoping for , lifepo4 instead of li-ion because of the fire danger as well as the pita of needing resistor bridges to make high resistance bridges in order to fool the bms included with the prius. With 14 blocks of 5s lifepo4 the bms should be perfectly happy. Of course I would need to...
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    Best way to make a 13Ah min up to 10c discharge 70 cell batt

    Looking into building a replacement battery design for The 2gen prius, with 5 cells per block I.e 16 V nominal per block the prius would monitor each of the 14 blocks. Total nominal voltage would be 224 V discharge would be about 100 A maybe 133.6 A intermittently 133.6 is the max designed draw...
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    Build your own CD battery tab welder for about $100.00+-

    By 1RC method, do you mean measure the time to charge to .63 (1-1/e) of the final (fixed) voltage? If you do this, I agree you need a very well regulated supply (or batteries). That's why I did the discharge test, since I know the final voltage is 0V ;) For the 1RC test (charging) you could...
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    Build your own CD battery tab welder for about $100.00+-

    hi there are some flaws in your technique, #1 self discharge on these types of caps are high this is why we don't remove the power supply till one >1s before welding, so you need to use something like a 10 ohm 10W resistor for the measurements. #2 you need to start off at the same voltage to...
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    Build your own CD battery tab welder for about $100.00+-

    use the 1rc method during charging from a non volitile power source (like a lead acid battery with two voltmeters to determine the capacitance, that means you need to know the time it takes to charge to 63% of the power sources voltage. if you use a regulated psu it will up the voltage and...
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    Build your own CD battery tab welder for about $100.00+-

    Ehh I bought an absolute USA Cap that was rated 2 Farads, and according to the 1rc method of charging (not discharging that's the other way of calculating) it only had 0.6F and you could tell by the welds as well So the pro ice brand is also a brand that seems to be true to the actual ratings...
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    Build your own CD battery tab welder for about $100.00+-

    wait a minute you understand hopw he turns off the scr? this is what I was looking for this whole time share the knowledge, as of right now I have not seen a method except for onsemi's way. I looked at that schematic of fritz's but with that e-paper I'm just not getting it. help and explain...
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    Build your own CD battery tab welder for about $100.00+-

    Hmm easy maybe, but most of us lack the capacity to measure one above 4000uF very accurately. there are two ways people estimate the actual capacity of a large (>4000uF) capacitor. One is the 1RC method,which as you well know as an electronic engineer is the time it takes for a capacitor to...
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    Build your own CD battery tab welder for about $100.00+-

    you try sunstone engineering http://www.sunstoneengineering.com/site/pages/sales they do ship internationally etc. GL terramir
  10. T

    Build your own CD battery tab welder for about $100.00+-

    Okies what brand of car cap is that there about to get a whole lot more business!!!!!!!!!!!!!!!!!!!!!! :o cause all the car caps we have seen so far have grossly exaggerated ratings! can you do a manual 1rc test over a voltage constant source to verify you capacitance meters accuracy? and BTW...
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    Build your own CD battery tab welder for about $100.00+-

    seen your closed source welder, you definetly spent more than 100 bucks on it. It's cool however it's definetly more than 100 bucks. You definetly got lucky on that car cap that it can go to 20V is astounding, most car caps can't. I think your welder is a bit overrated capacity wise since I...
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    Build your own CD battery tab welder for about $100.00+-

    The way that thing looks I suspect it's 2 0.6F to 1.5F stiffening caps and well about 4 farads worth of supercaps 6x25F in series in the middle. rip out the supercaps, and you'll have 1.2 to 3F of real low esr capacitance, this is what my welder is based on two parallel main stiffening caps out...
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    Build your own CD battery tab welder for about $100.00+-

    Not saying they won't do for a welder, hey just put em in a box,(safety first) but the price is a bit hefty, considering the audio caps while very overrated if you get the right one's you'll get it done for less I used 4 gauge stereo cable and 4 gauge bare wire from the home shmoo. also I used...
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    Build your own CD battery tab welder for about $100.00+-

    Very very cool after I do the plain all the plain battery tabs I have to do(over 1000x2) I might just work on moding it into something like that, however I would need to still be able to use it as a just plain spot welder And well for a plain spot welder the code would need to be modified to...
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    Build your own CD battery tab welder for about $100.00+-

    Well how many hours did they hold a charge before you timed a discharge curve and got a greater than 90% of charge? Big electrolytic capacitors of that grade should hold a fairly decent charge for days as for fast discharge, .25R is not what were dealing with in capacitive spotwelders more like...
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    Build your own CD battery tab welder for about $100.00+-

    oops applogize I read a pm of one of my friends wrong, it wasn't in the for sale thread it was here: http://endless-sphere.com/forums/viewtopic.php?f=2&t=2633&p=147530#p147530 and so on, if these things have been sitting around for years there is no way to dermine besides using them how long of...
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    Build your own CD battery tab welder for about $100.00+-

    Those are fairly old as people in the for sale forum pointed out. At the prices your asking for them there definetly not worth it. terramir
  18. T

    Build your own CD battery tab welder for about $100.00+-

    well yes audio caps are completly overrated. And well one thing is for sure those 5 farad ones that are a single cap size wise there is just no way, as for the power acoustik I would choose the 6F over the 5F volume wise, but since I dunno their quality you may end up with like 1-2 real farad(s)...
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    Build your own CD battery tab welder for about $100.00+-

    If you can afford the volfenhag 1.5F x2 you'll get around 2 farads, what the other guy posted probably be better though. from what I've read (and BTW I speak german lol (but born in usa) live in Lost Angeles now). you can probably use those at 19.5V all the time 20 should have a surge rating of...
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    Build your own CD battery tab welder for about $100.00+-

    :P that would make for some cool blow-ups, spectacular I might say LOL :twisted: That is an arc welding setup, and one of the problems is that the surface area is so small you couldn't put the ground contact on there. while the welder probably could be modified to work, i.e. eliminate the gas...
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    Build your own CD battery tab welder for about $100.00+-

    You might want to go with a car relay setup instead of an AC relay the low voltages that we use are unlikely to need the arc protection that an Ac relay uses, however the current protection of a 40amp 12V car relay is quite a bit better, and those relay's are cheaper as well :) I'd recommend...
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    Build your own CD battery tab welder for about $100.00+-

    Ehh I would think that is a rad idea except that microswitches will get burned out quite fast. at at max voltage quite a bit of current that is forced open from the NC position. Unless the microswitch is rated for a minimum of 3 to 4 the current level that the resistor limits it to at max...
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    Build your own CD battery tab welder for about $100.00+-

    hmmmmm, with the caps I really can't help ya cause I got special caps :p (two main caps out of hybrid caps I basically blackmailed (complained about their 2 farad cap being .6F max) and I went to the office to do it) so they gave me a whole 10F big shiny thing (which was like 5 farads total...
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    Build your own CD battery tab welder for about $100.00+-

    little hint many commercial systems have two types of electrodes, both sharp or one flat one sharp. Obviously the flat one is so you make one weld at a time even if you have to press both down on the tab material. Now with our ghetto systems we can achive the same thing by using the side of the...
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    Build your own CD battery tab welder for about $100.00+-

    I have an idea that might help but it would require a bit of re-machine-ing the holders and the probes. you could make them springloaded that way the probes would exert constant pressure regardless of the wear in the probe tips. the pressure would be equivalent to the springs. you'd just have...
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