eBay 8s alarms not really 8s ?

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Jestronix
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eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 18, 2016 7:43 am

So I got my little cell alarms in the mail today, and well they have 9 pins but only ever show 6s , have double triple checked wiring. I can even move the pins to test the the 7th and 8th cells, but never all together. I can't find any vids or shots of people using these with 8s. I call bullshit on these alarms from eBay's, good for 6s

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Have them wired as such

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Re: eBay 8s alarms not really 8s ?

Post by heathyoung » Oct 18, 2016 8:58 pm

The draw is very uneven. That's a given, and will unbalance cells given long enough. There are ways to get around this with unity gain opamps (I have some permanently connected to some LiPos).

If they are genuine CellLog 8S they will measure 8 cells. Sounds like a cheap knockoff.
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Re: eBay 8s alarms not really 8s ?

Post by Hillhater » Oct 19, 2016 12:03 am

What has the Celllog 8 got to do with this alarm unit ??
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Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 19, 2016 4:12 am

Hillhater wrote:What has the Celllog 8 got to do with this alarm unit ??
Used as an example

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Re: eBay 8s alarms not really 8s ?

Post by dogman dan » Oct 19, 2016 5:56 am

Blows that they only do 6s. I hate it when they dump pure trash like this, an obviously defective product.

Well, at least they were cheap. Try again at another source.

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Re: eBay 8s alarms not really 8s ?

Post by amberwolf » Oct 20, 2016 3:19 am

Interesting. I have a couple of this type that Ypedal sent me, and I just verified that (at least one of) mine *do* read 8s. Even if I plug in a 6s tap off my 14s pack first, and then 2s of the next most positive tap, it reads the 6s on the first cycle, then it will read all 8s on the next cycle.

I don't know that mine are exactly teh same as yours--maybe there was a batch not made right, or someone cloned them but got them wrong, dunno. Or maybe I got lucky and got a couple made correctly?

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Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 20, 2016 3:42 am

Yeh might try hobbycock again :(

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Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 23, 2016 11:22 pm

Ok so I opened one up what's thoughts ? I rekon they play these off as 8s knowing what 5% of people run 8s on the drones etc

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Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 24, 2016 5:59 am

I'm wondering if there is a reset and u have to hold the button in etc

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Re: eBay 8s alarms not really 8s ?

Post by amberwolf » Oct 24, 2016 2:07 pm

Not on mine. I can add or remove cells to/from the most positive end anytime even when others are connected and it just reads more or less cells on the next pass.

Not sure if mine looks like yours under the heatshrink/label, though it probably does.

Most likely the difference is in the programming, since yours reads cells regardless of which pins they're connected to, right? So all the hardware has to be working, just the MCU doesn't display them all?


Though...I havent' done a completely conclusive test, using 8 cells that I know are significantly different in voltage, all at the same time in a row so I can see that it is actually reading each individual cell and not repeating a measurement somewhere; it does appear to be working becuaes I get 8 readouts before it restarts the cycle.

I don't normally use them for 8s; I just tested it after seeing your post, on the EIG pack (that stays well-balanced on it's own) on CrazyBike2. The plugs are all 6s on there cuz that's what the Battery Medic and other RC type stuff I have for checking can all handle, so I'd usually just plug one into each of the first two 6s ports, and leave the 2s final one unmonitored, or use a different unit (I only have two of the kind above). Until this post came up it didnt' even occur to me to try them as 8s. :lol:

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Re: eBay 8s alarms not really 8s ?

Post by Hillhater » Oct 24, 2016 3:49 pm

I cant actually see any traces to the 7th and 8th pins on that board in the picture ?
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Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 24, 2016 7:24 pm

Thanks for testing , it only ever show 6cell on mine I've quadrupal checked wiring, so mush so if I move the checker pins down to the 7th 8th pins I can read them.

Yeh pin 7 looks missing or it's track is on the other side ? I'll unsolder it today and check

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Re: eBay 8s alarms not really 8s ?

Post by riba2233 » Oct 26, 2016 12:26 pm

There must be something wrong with yours, I got two and they both show 7s no problem, but I haven't tried 8s.

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Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Nov 19, 2016 4:57 am

Yeh all of mine were Shit from eBay and wildly out of range across the pins.

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Re: eBay 8s alarms not really 8s ?

Post by smeagol222 » Mar 14, 2017 6:32 am

I recently picked up some of these on Amazon, going to just return them. Any quality cell loggers out there not from hobbycock?
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Re: eBay 8s alarms not really 8s ?

Post by neptronix » Mar 14, 2017 6:48 am

celllog 8s.. expensive, but come calibrated pretty damn well from the factory and are quality.. i've been using the ones i bought in 2010 from hobbyking.

If for some reason you are morally opposed to hobbyking, you can find them at progressiveRC in the USA also.
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Re: eBay 8s alarms not really 8s ?

Post by smeagol222 » Mar 14, 2017 6:54 am

oh I'm not opposed to Hobbyking, its just after shipping and import duties and converting to CAD they get kinda expensive.

I wrote this in my build, but I guess the cellmeter might be best value?

price for 4pcs incl. shipping to me $65.65USD
https://hobbyking.com/en_us/hobbykingtm ... 2s-6s.html
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price for 4pcs incl. shipping to me $39.33USD
https://hobbyking.com/en_us/hobbykingtm ... alarm.html
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price for 4pcs incl. shipping to me $30.01USD
https://hobbyking.com/en_us/battery-monitor-2-6s.html
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Re: eBay 8s alarms not really 8s ?

Post by neptronix » Mar 14, 2017 6:57 am

Battery medics are extremely inaccurate and will disbalance your lipos. I'm surprised nobody has screamed about that in the reviews.

Who knows about the other components, but they are not made to high quality standards. Most things hobbyking sells are rebranded random chinese bits and pieces with no brand name behind them.

If you are dealing with RC Lipo, you want an accurate readout ( especially at the top of the charge ) because if anything goes wrong with lipos, it's kaboom for you.
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Re: eBay 8s alarms not really 8s ?

Post by smeagol222 » Mar 14, 2017 7:02 am

Geez- well you surely can't assume quality from the pricing eh? Do you happen to have a link on Hobbyking to the exact ones you use that seem to be decent?

I would be checking li-ion 18650's (5s10p groups) so not so explosive
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