eBay 8s alarms not really 8s ?

Batteries, Chargers, and Battery Management Systems.
Post Reply
Jestronix   10 kW

10 kW
Posts: 507
Joined: Jul 18 2015 4:59am

eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 18 2016 7:43am

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

Image

Have them wired as such

Image

heathyoung   1 MW

1 MW
Posts: 1542
Joined: May 27 2009 2:01am
Location: Newcastle, Australia

Re: eBay 8s alarms not really 8s ?

Post by heathyoung » Oct 18 2016 8:58pm

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.
GNG offroad build on Craftworks DHR with 12S2P lipo. Light, balanced, powerful, able to climb a tree.
Project Vectrii (2) - status - Finished. Nope. 38S Leaf cells are next. Now have 2 of them - Averages 50Wh/Klm

Hillhater   100 GW

100 GW
Posts: 9320
Joined: Aug 03 2010 10:33pm
Location: Sydney ..(Hilly part !) .. Australia/ Down under !

Re: eBay 8s alarms not really 8s ?

Post by Hillhater » Oct 19 2016 12:03am

What has the Celllog 8 got to do with this alarm unit ??
This forum owes its existence to Justin of ebikes.ca

Jestronix   10 kW

10 kW
Posts: 507
Joined: Jul 18 2015 4:59am

Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 19 2016 4:12am

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

User avatar
dogman dan   100 GW

100 GW
Posts: 34413
Joined: May 17 2008 12:53pm
Location: Las Cruces New Mexico USA

Re: eBay 8s alarms not really 8s ?

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

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.

User avatar
amberwolf   100 GW

100 GW
Posts: 25439
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: eBay 8s alarms not really 8s ?

Post by amberwolf » Oct 20 2016 3:19am

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?

Jestronix   10 kW

10 kW
Posts: 507
Joined: Jul 18 2015 4:59am

Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 20 2016 3:42am

Yeh might try hobbycock again :(

Jestronix   10 kW

10 kW
Posts: 507
Joined: Jul 18 2015 4:59am

Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 23 2016 11:22pm

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

Image

Jestronix   10 kW

10 kW
Posts: 507
Joined: Jul 18 2015 4:59am

Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 24 2016 5:59am

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

User avatar
amberwolf   100 GW

100 GW
Posts: 25439
Joined: Aug 17 2009 6:43am
Location: Phoenix, AZ, USA, Earth, Sol, Local Bubble, Orion Arm, Milky Way, Local Group
Contact:

Re: eBay 8s alarms not really 8s ?

Post by amberwolf » Oct 24 2016 2:07pm

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:

Hillhater   100 GW

100 GW
Posts: 9320
Joined: Aug 03 2010 10:33pm
Location: Sydney ..(Hilly part !) .. Australia/ Down under !

Re: eBay 8s alarms not really 8s ?

Post by Hillhater » Oct 24 2016 3:49pm

I cant actually see any traces to the 7th and 8th pins on that board in the picture ?
This forum owes its existence to Justin of ebikes.ca

Jestronix   10 kW

10 kW
Posts: 507
Joined: Jul 18 2015 4:59am

Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Oct 24 2016 7:24pm

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

User avatar
riba2233   1 MW

1 MW
Posts: 1811
Joined: Jun 30 2013 10:23am
Location: Croatia

Re: eBay 8s alarms not really 8s ?

Post by riba2233 » Oct 26 2016 12:26pm

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

Jestronix   10 kW

10 kW
Posts: 507
Joined: Jul 18 2015 4:59am

Re: eBay 8s alarms not really 8s ?

Post by Jestronix » Nov 19 2016 4:57am

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

User avatar
smeagol222   100 W

100 W
Posts: 135
Joined: Dec 17 2015 7:36am
Location: Toronto, Canada

Re: eBay 8s alarms not really 8s ?

Post by smeagol222 » Mar 14 2017 6:32am

I recently picked up some of these on Amazon, going to just return them. Any quality cell loggers out there not from hobbycock?
First project small E-scooter upgrade 1.5kw/3kw 48v 45a https://endless-sphere.com/forums/viewt ... 12&t=86228
Current project medium E-scooter upgrade 4kw/7kw 72v 90a https://endless-sphere.com/forums/viewt ... 10&t=85164

User avatar
neptronix   100 GW

100 GW
Posts: 12936
Joined: Jun 15 2010 5:56pm
Location: California refugee living in Utah, USA
Contact:

Re: eBay 8s alarms not really 8s ?

Post by neptronix » Mar 14 2017 6:48am

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.
My first major build: 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w on a Turner O2 full suspension.

User avatar
smeagol222   100 W

100 W
Posts: 135
Joined: Dec 17 2015 7:36am
Location: Toronto, Canada

Re: eBay 8s alarms not really 8s ?

Post by smeagol222 » Mar 14 2017 6:54am

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
Image

price for 4pcs incl. shipping to me $39.33USD
https://hobbyking.com/en_us/hobbykingtm ... alarm.html
Image

price for 4pcs incl. shipping to me $30.01USD
https://hobbyking.com/en_us/battery-monitor-2-6s.html
Image
First project small E-scooter upgrade 1.5kw/3kw 48v 45a https://endless-sphere.com/forums/viewt ... 12&t=86228
Current project medium E-scooter upgrade 4kw/7kw 72v 90a https://endless-sphere.com/forums/viewt ... 10&t=85164

User avatar
neptronix   100 GW

100 GW
Posts: 12936
Joined: Jun 15 2010 5:56pm
Location: California refugee living in Utah, USA
Contact:

Re: eBay 8s alarms not really 8s ?

Post by neptronix » Mar 14 2017 6:57am

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.
My first major build: 8T MAC motor on a Trek 4500.
The new all-arounder: Leafmotor 1500w on a Turner O2 full suspension.

User avatar
smeagol222   100 W

100 W
Posts: 135
Joined: Dec 17 2015 7:36am
Location: Toronto, Canada

Re: eBay 8s alarms not really 8s ?

Post by smeagol222 » Mar 14 2017 7:02am

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
https://endless-sphere.com/forums/viewt ... 10&t=85164
First project small E-scooter upgrade 1.5kw/3kw 48v 45a https://endless-sphere.com/forums/viewt ... 12&t=86228
Current project medium E-scooter upgrade 4kw/7kw 72v 90a https://endless-sphere.com/forums/viewt ... 10&t=85164

Post Reply