LiPo Battery True C Rate !!
02-24-2012, 09:37 AM
#61
01-07-2013, 10:11 AM
#62
As far as connectors and wires go there is no way they can handle the full C rate. This why C rate testing should be done on a cell. My jig to put the cells in is made of 1/4 inch copper.
If there would be a C rate standard and every factory would follow this standard you would notice that higher C rate cells will provide more power even if the wires and connectors can't handle the full C rate loads. This all comes back to the IR of the cells. Lower IR cells don't drop under load as much as higher IR cells.
If there would be a C rate standard and every factory would follow this standard you would notice that higher C rate cells will provide more power even if the wires and connectors can't handle the full C rate loads. This all comes back to the IR of the cells. Lower IR cells don't drop under load as much as higher IR cells.
Hi Danny...when will the IR 2s-6s meter be back in stock?
01-07-2013, 10:30 AM
#63
Turns out we have one in stock and I just posted it to our website so you can order it now if you want it.
The 1S-6S does the same as the 2S-6S it just has a small JST connector so you can plug a 2S-6S pack when testing 1S packs as the voltage of a 1S isn't enough to power the meter.
The 1S-6S does the same as the 2S-6S it just has a small JST connector so you can plug a 2S-6S pack when testing 1S packs as the voltage of a 1S isn't enough to power the meter.
01-07-2013, 10:39 AM
#64
Turns out we have one in stock and I just posted it to our website so you can order it now if you want it.
The 1S-6S does the same as the 2S-6S it just has a small JST connector so you can plug a 2S-6S pack when testing 1S packs as the voltage of a 1S isn't enough to power the meter.
The 1S-6S does the same as the 2S-6S it just has a small JST connector so you can plug a 2S-6S pack when testing 1S packs as the voltage of a 1S isn't enough to power the meter.
Hi Danny...thanks for getting back so quick...wont be ready to order for a couple of weeks...still deciding on a charger which may do the same thing..but after reading yours posts, I think this is a way better way of checking...so I will probably switch gears and save money and not get the REVO PL6..which is the only reason I was buying it...
01-07-2013, 10:48 AM
#65
The PL6 is a great charger but the way it measures IR isn't that great in my opinion. I have a PL8 and it's always giving me high IR on one of the cells but on the ESR meter both cells are very similar.
When testing a 6000-3S the PL8 was giving me decent IR per cell but on the ESR it was very high and on the GFX it was high so this is why I don't think the way it measures IR is all that accurate.
When testing a 6000-3S the PL8 was giving me decent IR per cell but on the ESR it was very high and on the GFX it was high so this is why I don't think the way it measures IR is all that accurate.
01-07-2013, 10:53 AM
#66
The PL6 is a great charger but the way it measures IR isn't that great in my opinion. I have a PL8 and it's always giving me high IR on one of the cells but on the ESR meter both cells are very similar.
When testing a 6000-3S the PL8 was giving me decent IR per cell but on the ESR it was very high and on the GFX it was high so this is why I don't think the way it measures IR is all that accurate.
When testing a 6000-3S the PL8 was giving me decent IR per cell but on the ESR it was very high and on the GFX it was high so this is why I don't think the way it measures IR is all that accurate.
I agree....and from what I am reading, the ichargers aren't much better...
I am just staring to back into racing after open heart surgery recovery....so I am trying assess my needs...I will only be running one class, a buggy, indoors....not sure I need all the PL6 features..or the Hyperions for that matter, to charge a couple of packs between heats...
probably gonna stick to the IMAX ultimate 200 watt charger for the time being...If I can get back into it, Iand race 1/8th scale buggy this summer with 4s cells, I will worry about it then...and get a more powerful charger and pick up the ER meter as well...
01-07-2013, 03:52 PM
#67
Great post best read on rc tech to date and to Danny at SMC for taking the bull by the horns and triing not to let the batt game get out of hand. I was just triing to figure all this out myself and came across this post. I bought a orion touch charger and it has a IR read out for it. Ive run the Reedy packs 4000 60c and 4100 65c have not liked them compared to the Turnigy nano packs 4200 65c-120c. Much more punch from the Nanos and they are only $33 bucks. Is the nano tubes tech the wave of the future compared to the way lipo r made today, and y havent the 123 batts tech ever taken off?
01-07-2013, 05:08 PM
#68
Great post best read on rc tech to date and to Danny at SMC for taking the bull by the horns and triing not to let the batt game get out of hand. I was just triing to figure all this out myself and came across this post. I bought a orion touch charger and it has a IR read out for it. Ive run the Reedy packs 4000 60c and 4100 65c have not liked them compared to the Turnigy nano packs 4200 65c-120c. Much more punch from the Nanos and they are only $33 bucks. Is the nano tubes tech the wave of the future compared to the way lipo r made today, and y havent the 123 batts tech ever taken off?
03-08-2013, 08:47 PM
#69
bros here, i would like to know what is a roar approved lipo? what are the processes the battery tested so as to get the "label"? how are the sampling size of the roar approval lipo being tested before shipping out from a manufacturer?
want to learn more, please kindly share.
want to learn more, please kindly share.
03-09-2013, 02:49 AM
#70
Tech Adept
Thought I might chime in and add a few twists to the tale, well really a question to get you all thinking, why worry about a continuous discharge rating, are ESC's these days delivering a continuous voltage and current to the motor? I deliver a challenge to you all, go open up your ESC find the lovely wee product code on one of the output fets and google the data sheet for it, then compare the current ratings for continuous and pulsed, taking into account opperating temp as well. Then once you have shone a light on things a little more, open up one of your hard case batteries and look at the connections inside, then look really deep into your wallets, as that is the void created by worrying about C ratings. Finally use google to look up a few more things, Ohms Law, Lens's Law and the good old power triangle, these will all help to start the replenishment to the wallet. Oh and one more thing the internal resistance of cells, well is this really needed, again just another varying load of cobswobble to sell more crap to people. The batteries you buy will only affect you driving by about 1%, the time spent practicing your driving and setup instead of worrying about advertising jargon is priceless. And lastly a question on internal resistance, how many ohms in resistance rise will create a drop of 50% in output power at a draw of 60Amps? I await the replies.
03-09-2013, 03:27 AM
#71
Thought I might chime in and add a few twists to the tale, well really a question to get you all thinking, why worry about a continuous discharge rating, are ESC's these days delivering a continuous voltage and current to the motor? I deliver a challenge to you all, go open up your ESC find the lovely wee product code on one of the output fets and google the data sheet for it, then compare the current ratings for continuous and pulsed, taking into account opperating temp as well. Then once you have shone a light on things a little more, open up one of your hard case batteries and look at the connections inside, then look really deep into your wallets, as that is the void created by worrying about C ratings. Finally use google to look up a few more things, Ohms Law, Lens's Law and the good old power triangle, these will all help to start the replenishment to the wallet. Oh and one more thing the internal resistance of cells, well is this really needed, again just another varying load of cobswobble to sell more crap to people. The batteries you buy will only affect you driving by about 1%, the time spent practicing your driving and setup instead of worrying about advertising jargon is priceless. And lastly a question on internal resistance, how many ohms in resistance rise will create a drop of 50% in output power at a draw of 60Amps? I await the replies.
I agree with you. Looking at one value in isolation makes interpreting its significance meaningless most of the time. At the end of the day, what we are really trying to look at and compare is work.
Does lowering the IR value of a pack lead to more work out of the system and if so, then by how much?. If the answer is no, then there is no need to worry about it. Things need to be demonstrable and have meaning. Pack A has an IR of 0.5 pack B has an IR of 0.6. So what, what does it mean, and does it even matter. If the rest of the system has a resistance value higher than these 2 values, neither pack is going to lead to more work from the system.
The same can be said for fall off rates. Pack A falls off at 7m and pack B at 8m, if you only race a 5m race, then neither is important and not leading to more work from the system.
At the end of the day, i will stick to the tried and true method of determining the quality of a pack. I will put it in my car and run my standardized series of tests to see just how it performs in a real world situation.
03-09-2013, 03:41 AM
#72
Thought I might chime in and add a few twists to the tale, well really a question to get you all thinking, why worry about a continuous discharge rating, are ESC's these days delivering a continuous voltage and current to the motor? I deliver a challenge to you all, go open up your ESC find the lovely wee product code on one of the output fets and google the data sheet for it, then compare the current ratings for continuous and pulsed, taking into account opperating temp as well. Then once you have shone a light on things a little more, open up one of your hard case batteries and look at the connections inside, then look really deep into your wallets, as that is the void created by worrying about C ratings. Finally use google to look up a few more things, Ohms Law, Lens's Law and the good old power triangle, these will all help to start the replenishment to the wallet. Oh and one more thing the internal resistance of cells, well is this really needed, again just another varying load of cobswobble to sell more crap to people. The batteries you buy will only affect you driving by about 1%, the time spent practicing your driving and setup instead of worrying about advertising jargon is priceless. And lastly a question on internal resistance, how many ohms in resistance rise will create a drop of 50% in output power at a draw of 60Amps? I await the replies.
But the internal resistances also tell us how well balanced the packs are, how much they'll heat up during use (we don't want any power wasted as heat, though some is inevitable).
It can also tell us the quality of the cells inside as the cheaper items seem to deteriorate quicker and go further out of balance during use.
Last but not least, it was pointed out to me after a former UK national winner tried a car with my lipo and one of his, that his lipo had more punch out of the corners. When I measured my lipo the resistance had built up quite a long way compared with his less used newer lipo.
It doesn't take much of a drop in performance for it to become noticable. One minute you're as fast as everyone down the straight, the next thing you know they're slowly eating into you on the straight every time you are flat out.
03-09-2013, 05:30 AM
#73
I'll go one further... I bought a new $100 Reedy 100C "orange" pack and ran it vs. my older Turnigy $35 50C-100C pack... The result? I'm not too happy that I spent 3x for an inferior battery...but I do like the orange color. I just don't like that I paid $65 more for it! This "motor and battery" wars is what got me out of the racing scene 15 or so years ago. Even though money is not an issue for me now (but my wife blocking my spending is), I still get a bad taste in my mouth when I get cheated. I will try a "supposed superior" product ONCE to do my personal testing, but I will NEVER buy a Reedy pack again because of this. Best bang for the buck is the Turnigy for me. Just as a note, I previously ran Thunder Power 45C. Again $100 each. Zero difference in laptimes and/or punch feel compared to the Turnigy 20C-40C $20 battery... These are my opinions based on my personal findings, so your results may vary.
I Run on a very long nitro track often. Low turn mod motors and high boost, the Reedy packs puff up less and and are much faster down the straight than most other batteries I have tried. This tells me 2 things: they have a lower IR and higher C rating. How much, I am not sure, but it gets the job done almost too well. 2 weeks ago, while running my positive wire from battery to speedo was coming unsoldered at the ESC. This tells me the amps being drawn were probably peaking at a very high point. I could probably data log it, and this would help determine at least what kind of peak bursts we can see.
03-09-2013, 05:39 AM
#74
can someone list the grade "a" batteries then, so the rest of us know which are worth buying, since they are all built in the same country, which manufacture gets the proper built cells,if anyone has this info please let us know thanks
03-09-2013, 05:40 AM
#75
Reedy does not make orange or 100C rated batteries. What they do offer, I have found to be more reliable than most batteries out there.
I Run on a very long nitro track often. Low turn mod motors and high boost, the Reedy packs puff up less and and are much faster down the straight than most other batteries I have tried. This tells me 2 things: they have a lower IR and higher C rating. How much, I am not sure, but it gets the job done almost too well. 2 weeks ago, while running my positive wire from battery to speedo was coming unsoldered at the ESC. This tells me the amps being drawn were probably peaking at a very high point. I could probably data log it, and this would help determine at least what kind of peak bursts we can see.
I Run on a very long nitro track often. Low turn mod motors and high boost, the Reedy packs puff up less and and are much faster down the straight than most other batteries I have tried. This tells me 2 things: they have a lower IR and higher C rating. How much, I am not sure, but it gets the job done almost too well. 2 weeks ago, while running my positive wire from battery to speedo was coming unsoldered at the ESC. This tells me the amps being drawn were probably peaking at a very high point. I could probably data log it, and this would help determine at least what kind of peak bursts we can see.