Internal resistance tester

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999zip999   100 GW

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Internal resistance tester

Post by 999zip999 » Jan 30 2012 10:22pm

I was looking for internal resistance tester. there was a thread about one but couldn't find it. If any one could help. i think it was 39.99usd . Thanks

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neptronix   100 GW

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Re: Internal resistance tester

Post by neptronix » Jan 30 2012 10:51pm

I'm thinking an expensive multimeter would work... am i right?
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Re: Internal resistance tester

Post by Spicerack » Jan 30 2012 10:59pm

Maybe a real expensive multimeter- to measure the Ri it needs to send an AC pulse through the battery... most of the time it's a very expensive piece of equipment!

You can do a cheap and nasty test but it's not terribly accurate:

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Re: Internal resistance tester

Post by Ykick » Jan 30 2012 11:10pm

Voltage drop and current will give you a ballpark but as Andy noted more accurate method uses pulses and another method with sine wave phase shift of V and I to determine resistance of single cells.
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neptronix   100 GW

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Re: Internal resistance tester

Post by neptronix » Jan 30 2012 11:16pm

Yeah, that will measure Ohm, but many lithium batteries will be in the mOhm range..
I know the iCharger and Hyperion chargers can do it; not the most accurate devices in the world, but they give you a general idea upon which to compare other batteries.

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Re: Internal resistance tester

Post by IBScootn » Jan 30 2012 11:57pm

Check out the model 20R for around $50 out on eBay:
http://www.ebay.com/itm/20R-Internal-Ba ... 4636wt_922

I bought one to test out,

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Re: Internal resistance tester

Post by 999zip999 » Jan 31 2012 12:32am

Yes, I be scoot em. I think that be the one i'ave been thinking of. Does It work ? It has a kelvin 4 wire probe ? That one ? Thanks guys

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Re: Internal resistance tester

Post by neptronix » Jan 31 2012 12:39am

Ya know.. you could get an iCharger 106b+ for $80.. then.. you'd have an iCharger b+ :P

Just sayin ;)
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Doctorbass   100 GW

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Re: Internal resistance tester

Post by Doctorbass » Jan 31 2012 1:18am

IBScootn wrote:Check out the model 20R for around $50 out on eBay:
http://www.ebay.com/itm/20R-Internal-Ba ... 4636wt_922

I bought one to test out,
Yeah.. I aproove, I bought many of those for me and friends.

They work pretty well and accurate.. but they dont tolerate reverse polarity :roll:

So i modified them in two way:

- 4 wire kelvin measurement probe with seperate spring loaded pins for the current sens and the bleed

-I installed a relay that allow to contduct the tested cell and the tester only when the polarity is ok.. simple, cheap and save you from having blown tester!


I paid like 90$ for 3

I will post my review about it ( the SM8124)in the next hour.

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Re: Internal resistance tester

Post by Doctorbass » Jan 31 2012 2:09am



Doc
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Re: Internal resistance tester

Post by IBScootn » Jan 31 2012 1:33pm

Thanks for the video doctorbass. Seems like it would be good to put this info into the ES wiki.

Could you also show how you made the modified test probe? I didn't see any dual pogo probes out on eBay, so assuming you just soldered the leads to the pogo pins and shrink-wrapped them up??

Mine is still on slow-boat from china - don't expect to see it anytime soon. But when I get it, I'll modify the leads to pogo; but sounds like I'll need to come up with another reverse polarity protection approach as I have lifepo cells. Dang, I hate products without reverse polarity protection. Anyways, thanks again for the heads-up.
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Re: Internal resistance tester

Post by 999zip999 » Jan 31 2012 10:49pm

Thank's Doc that on target need to see again.

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Re: Internal resistance tester

Post by 999zip999 » Jan 31 2012 11:42pm

Shippiing march 1. Couldn't find a faster way ? On ebay ?

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Re: Internal resistance tester

Post by amberwolf » Feb 01 2012 12:47am

They probably sell first, then when they have enough sold they manufacture them. (or order them from some other company).

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Re: Internal resistance tester

Post by sangesf » Feb 01 2012 1:26pm

Doctorbass wrote:

Doc

Where can I get one of those impotence meters?

LOL.. Gotta love yer accent.. That made my day..

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Re: Internal resistance tester

Post by cassschr1 » Feb 01 2012 1:58pm

Doc , when hooked up with reverse polarity just 1 time, say on 4.2 cell does it still blow?
What are the results...like does other functions still work, or does the screen go blank? I have one of these and about a year ago I thought something wasn't right,but didn't know what.

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Doctorbass   100 GW

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Re: Internal resistance tester

Post by Doctorbass » Feb 01 2012 4:04pm

cassschr1 wrote:Doc , when hooked up with reverse polarity just 1 time, say on 4.2 cell does it still blow?
What are the results...like does other functions still work, or does the screen go blank? I have one of these and about a year ago I thought something wasn't right,but didn't know what.

Yes it blow with low voltage too.

The result are that the reading on the LCD make non sense and the measured value is variating and not way from the real value.

no blank display.. just wront displayed value
CURRENT PROJECT: 2WD duo MXUS/Max-E ebike 32kW
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-Succeded to haul a 19200 pounds schoolbus!
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999zip999   100 GW

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Re: Internal resistance tester

Post by 999zip999 » Feb 01 2012 9:11pm

O.k. IBScootingn I order one to wonder if they come on the same boat as amberwolf quessed. Tell me when you get yours and i will tell you when i get mine. Ha Ha . Same boat ?

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Re: Internal resistance tester

Post by Kin » Feb 02 2012 11:44am

Hmm, so is this tester using some more accurate process than the "two resistors in parallel w/known load voltage drop" calculation?

Just wondering, because right now $40 seems like a substantial price to drop for it, if its not going to offer some sort of long term quality.
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Re: Internal resistance tester

Post by SamTexas » Feb 02 2012 12:42pm

andynogo wrote:Maybe a real expensive multimeter- to measure the Ri it needs to send an AC pulse through the battery... most of the time it's a very expensive piece of equipment!

You can do a cheap and nasty test but it's not terribly accurate:
Thanks andynogo for the video. One question: What exactly is that cyclindrical blue load device you used?

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Re: Internal resistance tester

Post by 999zip999 » Feb 02 2012 9:33pm

It's a coil of some kind of wire for resistance. But what kind and for how long ? Yes ?

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Re: Internal resistance tester

Post by Spicerack » Feb 02 2012 11:24pm

Aaah sorree you misunderstanddeee!

Not my video. Shamelessly stolen from youtube, so no idea what value the load is. It's most likely enamelled winding wire. I'm not sure about his resistance value though- I hope he calibrated the multimeter first as quite often they will show about 4ohms just across the test leads....

A better way if you use this method would be to use a proper resistor with a low tolerance.
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Was Cellman MAC rear oil cooled then 8x8 9C vented and temp probed now 9x7 9C vented and temp probed!
12 FET controller
62V 18650 home made battery pack
50 km/h
http://endless-sphere.com/forums/viewto ... =6&t=32769
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Re: Internal resistance tester

Post by IBScootn » Feb 08 2012 6:02pm

999zip999, my ship came in (ie 20R IR meter arrived today). Shipped Jan29, arrived Feb 8.

Seems to work fine, but need to install the pogo pins as it's too hard to get a good contact with standard probes. But with a little effort, I was able to verify my two new GBS 40AH cells were 2.5mOhms. Once I buy the pogos (yes I forgot to), and get them installed it will be interesting to see if my older 24 cells show any IR increase.
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Re: Internal resistance tester

Post by IBScootn » Feb 09 2012 1:21am

Doctorbass or anyone,

What pogo tips should I buy for the IR meter? I now remember why I didn't buy them earlier - too many choices: P50, P75, P100, pin only or pin & receptacle, etc. Can someone recommend an item off eBay to buy.

Thanks
Motorcycles:
ZEV T7100, 84V, 60AH, 65+mph; Mods: TNC throttle, windshield, Cycle Analyst , Cell Log , and custom charger
Kymco GT300i - for long rides through the Rocky Mountains
Big EV Grin. :)

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Re: Internal resistance tester

Post by Doctorbass » Feb 13 2012 12:34am

IBScootn wrote:Doctorbass or anyone,

What pogo tips should I buy for the IR meter? I now remember why I didn't buy them earlier - too many choices: P50, P75, P100, pin only or pin & receptacle, etc. Can someone recommend an item off eBay to buy.

Thanks

These one seem perfect!

http://www.ebay.com/itm/10pcs-P75-E2-Di ... 079wt_1396
CURRENT PROJECT: 2WD duo MXUS/Max-E ebike 32kW
http://endless-sphere.com/forums/viewto ... =3&t=65764
-Fastest speed record 117 km/h on flat
-Fastest 1/4 mile@ 114km/h on flat and 16.316 sec
-Succeded to haul a 19200 pounds schoolbus!
113kmh Gianthttp://www.evalbum.com/3406
Mongoosehttp://www.evalbum.com/1947
YOUTUBE---https://m.youtube.com/user/Doctorbasss
http://twitter.com/DocbassMelancon
I speak FRENCH and english

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