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Old Feb 11, 2014, 10:17 AM
Radio-active flyer
Rem Fodder's Avatar
Canada, ON, Port Hope
Joined Apr 2012
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Gents, I have a question for you all. I going to be adding a Powerlab 6 charger soon to my arsenal of tools. Looking at the Revolectrix website I see that lipo's are available for mail order. I am just curious if anyone has any experience with them? Prices seem reasonable and they have some battery data available on the site. See link. Thanks in advance.

http://www.revolectrix.com/lipo_terms.htm
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Old Feb 11, 2014, 11:13 AM
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Georgia
Joined Jun 2007
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The lipo's should be fine, and have a good reputation.
In the US, recent issues with shipping lipos seem to have subsided, at least for the lower capacity batteries.
A remaining US issue has to do with unexpected charges from banks. Seems that the law allows banks to add a foreign transaction fee on top of any foreign currency exchange fee or commission. This usually shows up only on a credit card statement, and may not on the web based transaction information from the bank. (At least for several days after the original transaction first appears.) Banks will usually remove the additional fee when asked, as a customer satisfaction issue.
When E-Bay/Pay pal transactions are involved, there is a possibility that a US store transaction actually pays to a foreign account, unknown to the customer, until the extra fee shows up on the credit card statement or on line records.
Revolectrix uses or has used the Leo Industries pay to account, which is considered to be a foreign account by US banks, even when the transaction occurred and merchandise was shipped from the US store.
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Old Feb 11, 2014, 11:14 AM
ΜΟΛΩΝ ΛΑΒΕ
habitforming's Avatar
USA, KY, Hebron
Joined Dec 2005
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Quote:
Originally Posted by Rem Fodder View Post
Gents, I have a question for you all. I going to be adding a Powerlab 6 charger soon to my arsenal of tools. Looking at the Revolectrix website I see that lipo's are available for mail order. I am just curious if anyone has any experience with them? Prices seem reasonable and they have some battery data available on the site. See link. Thanks in advance.

http://www.revolectrix.com/lipo_terms.htm
See recent posts in this thread: http://www.rcgroups.com/forums/showt...767093&page=12

A very generous RCG member has devoted a large sum of money and time to benchmarking various high power lipos, and Revo is one of the brands that has been included in his testing. (spoiler - they have shown to be good quality, good performing packs)
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Old Mar 03, 2014, 11:11 AM
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United States, NJ, Newark
Joined Nov 2005
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Is that a reason why the last cell is quasar higher than the others?
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Old Mar 04, 2014, 10:20 PM
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Rem Fodder's Avatar
Canada, ON, Port Hope
Joined Apr 2012
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Thanks for the input guys. My PL6 showed up last week, just waiting for the power supply now. Been checking the Revo site for their Black 5000 mah packs, but they are still out of stock. And thanks for the link regarding the battery testing thread. Some great material posted, and certainly a learning experience reading through it.
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Old Mar 22, 2014, 12:16 AM
chuck
santa barbara, CA
Joined May 2009
3,999 Posts
guys , hope this is not to o/t for here but i feel this is the best place to ask, if there are any updated opinions on the Wayne Giles’ ESR/IR meter vs the icharger106b for ir measuring. i have read this thread and most of the esr thread and am in the market. i understand how the esr meter measures but not completely on the 106b. i read the manual but it was not real descriptive.

i dont really need another charger but it cant hurt, my need is mostly ir. i know there have been numerous comments re. both units being accurate , wondered if any had further comments. the money is about the same so that's not an issue.

does the 106b do both cell and pack ir or just add up the individual cells? being able to compare total cell ir against pack ir seems like a very useful tool for finding issues other than just individual cell problems.

am i correct in understanding that the 106b uses a standard balance plug where the esr meter uses 2 pins only that must be moved for each cell?

also it sounds like the esr meter measures quickly whereas i could not find the procedure w/ the 106b.

sorry if these question have already been asked , i tried to do my homework before asking.

any and all input appreciated!

tia, chuck.
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Old Mar 22, 2014, 12:54 AM
ancora imparo
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Melbourne, Australia
Joined Jul 2005
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Chuck, I use both (as does Mark Forsyth who may chime in). The iCharger can measure IR while charging like many other chargers but is unique AFAIK in that it can also be used as a stand alone IR meter using the high current discharge method same as the ESR meter.

Critical points:

1) The iCharger agrees closely with the ESR/IR meter.

2) It has, however much lower resolution. That is, it displays only to 1 mOhm resolution which on a modern big LiPo is a fairly large % of the cell IR which may be down in the 3-4mOhm range. The ESR/IR meter has a resolution of 0.3mΩ for a pack and 0.04mΩ for a single cell.

3) Using Discharge IR measurement on the iCharger it measures all cells at once and also the pack IR. It takes about 100mS total. The ESR meter takes 25mS/cell - in effect both are instantaneous. The ESR meter requires each cell to be read individually but you still have to power the iCharger up externally for it to work. The ESR meter is self powered. On balance I would say convenience and speed is better for the ESR meter unless you already have the iCharger powered.

4) The ESR/IR meter is hand made individually calibrated instrument specifically designed for the job. The IR measurement on the iCharger is a bonus add-on to a charger.

IMO they aren't really comparable.

If you are serious about measuring IR on large capacity packs, the ESR meter is the only viable solution I know of. If you mainly use smaller packs with moderate IR (like 2200mAh packs), the iCharger does a good job but is not as as precise (although it is perfectly accurate).

John
Quote:
Originally Posted by chas650r View Post
guys , hope this is not to o/t for here but i feel this is the best place to ask, if there are any updated opinions on the Wayne Giles’ ESR/IR meter vs the icharger106b for ir measuring. i have read this thread and most of the esr thread and am in the market. i understand how the esr meter measures but not completely on the 106b. i read the manual but it was not real descriptive.

i dont really need another charger but it cant hurt, my need is mostly ir. i know there have been numerous comments re. both units being accurate , wondered if any had further comments. the money is about the same so that's not an issue.

does the 106b do both cell and pack ir or just add up the individual cells? being able to compare total cell ir against pack ir seems like a very useful tool for finding issues other than just individual cell problems.

am i correct in understanding that the 106b uses a standard balance plug where the esr meter uses 2 pins only that must be moved for each cell?

also it sounds like the esr meter measures quickly whereas i could not find the procedure w/ the 106b.

sorry if these question have already been asked , i tried to do my homework before asking.

any and all input appreciated!

tia, chuck.
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Old Mar 22, 2014, 09:45 AM
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So. Cal.
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I agree with John 100%, Chuck. For smaller packs (2200mAh and lower), the iCharger will be just fine for most folks. For larger packs (3000mAh and up) that are to be used for competitive purposes, the ESR Meter is the best tool.

Some of my previous thoughts on this:

http://www.rcgroups.com/forums/showp...76&postcount=8

http://www.rcgroups.com/forums/showp...&postcount=105

Mark
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Old Mar 22, 2014, 10:41 AM
chuck
santa barbara, CA
Joined May 2009
3,999 Posts
thanks guys . great answers and great work here . as my battery stock is mostly 3000's and below it sounds like the icharger will do the job. i have had for quite some time an duratrax ice charger/ discharger . it has a pack ir function that has been very helpful when combined w/ what i have learned lurking about here and in the esr thread. my unit uses the discharge plug only, if i understand my unit correctly it measures 120 sec into a charge run by stopping the charge momentarily and comparing on and off load voltages? from all i have learned in the threads i use a 1c charge rate at a controlled temp and the gained info has been incredible. all of my packs have deans that i have soldered and after 40+years of soldering i like to think i am good at it , so this has mostly eliminated the connector variable. using this info (with a grain of salt due to how i got the info) and the performance tool has been a real eyeopener. obviously i can only extrapolate cell ir #'s from the pack #'s but w/ controlled temp and the same connectors , as a comparison tool its worked well.

as a veteran electrician of to many years and someone that understands electronics just enough to be dangerous, i cant wait to compare the old info with new from a reliable source. most of my battery use is small to med sized edf ( 70mm and less) and finding batteries that will do the job AND last is a as you know a chore to say the least. thanks to all of you who help make the "lie detection process" a reality

keep up the good work!

chuck.
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Old Mar 22, 2014, 09:59 PM
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Canton, Michigan USA
Joined Jul 2007
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Quote:
Originally Posted by chas650r View Post
thanks guys . great answers and great work here . as my battery stock is mostly 3000's and below it sounds like the icharger will do the job. i have had for quite some time an duratrax ice charger/ discharger . it has a pack ir function that has been very helpful when combined w/ what i have learned lurking about here and in the esr thread. my unit uses the discharge plug only, if i understand my unit correctly it measures 120 sec into a charge run by stopping the charge momentarily and comparing on and off load voltages? from all i have learned in the threads i use a 1c charge rate at a controlled temp and the gained info has been incredible. all of my packs have deans that i have soldered and after 40+years of soldering i like to think i am good at it , so this has mostly eliminated the connector variable. using this info (with a grain of salt due to how i got the info) and the performance tool has been a real eyeopener. obviously i can only extrapolate cell ir #'s from the pack #'s but w/ controlled temp and the same connectors , as a comparison tool its worked well.

as a veteran electrician of to many years and someone that understands electronics just enough to be dangerous, i cant wait to compare the old info with new from a reliable source. most of my battery use is small to med sized edf ( 70mm and less) and finding batteries that will do the job AND last is a as you know a chore to say the least. thanks to all of you who help make the "lie detection process" a reality

keep up the good work!

chuck.
Chuck,

The ESR meter standalone in terms of convenience. It belongs in your tool bag. I use it when buying packs from my LHS where I just brought it with me to test some highly touted house brand lipos. Geeze, the darn packs must have been new old stock with each cell measuring 15 -17 m ohms each when you know a proper new pack should be below 5 mohms or less. It saved me wasting my money. By the way, they no longer sell these house brand lipos.

Bill
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Old Mar 23, 2014, 02:41 AM
aka JetMan Joe
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Joined Feb 2010
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+1 on the ESR meter. I know the thread supports this throughout but I beat my head against the wall for a while using various chargers trying to determine usable and consistant IR numbers. So I just have to thank John and Mark (and of course Wayne) for steering me the right way a while back.

Joe
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Old Apr 27, 2014, 06:37 PM
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Rather than get into "standards" for IR measurement.
I consider it a useful way to compare cells in the same battery, or a similar battery against another.
Since this is all relative, and the same charger is used. the comparisons are valid.
I have no idea how and if the IR rating, (other than a rough guess) might correlate to the accuracy of a "C" rating.

How I might go about trying to get an idea of a C rating for a particular battery.

In flight, we usually set an ESC to go into a shutdown or reduced power mode at 3.2V or so.
So, at any point in flight, this voltage is useful as an indication of the maximum current draw for a particular battery.

If I had the ability to easily provide a load on the bench that duplicated the in flight load that resulted in 3.2v per cell, that would represent the maximum useful current capability of that battery at that point in time and charge.

I would expect to find that the maximum current capability decreases as the charge decreases. I'd also easily believe that tow otherwise similar lipos, same mfr, same ratings, etc. with significantly different IR readings on my charger would have a noticeably different maximum useful current capability.
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Old Apr 27, 2014, 07:16 PM
aka JetMan Joe
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Joined Feb 2010
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Hi Chuck, there's some lipo performance information here:
http://www.rcgroups.com/forums/showt...3#post23223191

Joe
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