# Cell-Log 8 review



## etischer (Jun 16, 2008)

I've placed an order for some Cell Log 8's and while I still have the oppertunity to cancel my order, I was wondering if Jack could provide more info about the failure he experienced. Pictures would be nice too. I have no experience with the cell logs (yet), so I'm hoping someone could shed light on what might have gone wrong. 

Are the pins loose in the molded connector allowing pins to fall out? 

Was a wire pinched causing a short?

Did the Cell log get wet?

Was there a failure in the Cell Log which caused it to over heat and melt the molded connector? Jack, can you open it up and see if there are any burn marks inside?

I imagine if the wire was glowing red hot, the short occured somewhere other than the circuit board. Was the wire burned all the way up to the molded connector? Was only one wire burned? 

Can we get feedback from others who are using the Cell-Log8?


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## JRP3 (Mar 7, 2008)

Jack said the Celllog was still functioning after the meltdown, and I believe one wire had all the insulation burned off. The connector was melted into the Celllog and they couldn't pull it out last I knew.


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## major (Apr 4, 2008)

etischer said:


> Can we get feedback from others who are using the Cell-Log8?


Hi etisch,

Check out this thread http://www.diyelectriccar.com/forums/showthread.php/lithium-battery-monitor-39708.html 

I have had pretty good luck with the CellLog8s. I have 5. One had the USB connect go dead when we connected to the laptop while it still had the battery connections. The manual (which isn't the best) said this was permissible. But I'll never do it again. Just disconnect it from the battery first and then connect the USB to the computer.

Besides that, they look like tough little devices. They are intended for model airplanes and such, to stay aboard while in flight. So they are small and light weight, but seem rugged.

I have logged maybe several hundred hours on my CellLog8s. I bought the correct connectors (JST from DigiKey) and got enough to make a few dozen harnesses. I also bit the bullet and bought 9 colors of #22 wire. I leave the harness and connector on the battery and just unplug the CellLog8 and move it around. Works great and I never had a short or anything like that.

The data log transfer program worked with WindowsXP but not with Vista or Windows7. My laptop with XP got the USB damaged from the CellLog incident, so now I don't have a way to download data. I would appreciate it if someone out there could help me get it talking to Windows7. I'd start posting test graphs again 

I'd say get yourself a couple of CellLog8s and the right connectors. For $28 each, forgetaboutit. Oh yeah, delivery takes about 4 or 5 weeks.

Regards,

major


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## JRP3 (Mar 7, 2008)

So they don't come with connectors?  Did you get them from Hobby City? I just ordered one from EPBuddy, http://epbuddy.com/index.php?main_page=index&cPath=8&zenid=9i5dg7vdovt76g9kbh7fmpb6h5
$34.80 with "free shipping".


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## JRP3 (Mar 7, 2008)

major said:


> The data log transfer program worked with WindowsXP but not with Vista or Windows7. My laptop with XP got the USB damaged from the CellLog incident, so now I don't have a way to download data. I would appreciate it if someone out there could help me get it talking to Windows7. I'd start posting test graphs again
> major


You should be able to run WinXP in Microsoft Virtual machine or VMware within Win7, I think.


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## etischer (Jun 16, 2008)

If the harness does not come with the cell log, perhaps the problem Jack experienced was due to a poorly assembled harness and not a bad Cell-Log. 

Thanks for the link Major, good stuff. I saw the harness being sold on Ebay, but it seems pretty pricey. Do you have the Digikey part number of the connector you are using? I got too many results searching for JST and would like to use the "tried and true" connector. 




major said:


> I bought the correct connectors (JST from DigiKey) and got enough to make a few dozen harnesses. I also bit the bullet and bought 9 colors of #22 wire. I leave the harness and connector on the battery and just unplug the CellLog8 and move it around. Works great and I never had a short or anything like that.


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## major (Apr 4, 2008)

JRP3 said:


> So they don't come with connectors?  Did you get them from Hobby City? I just ordered one from EPBuddy, http://epbuddy.com/index.php?main_page=index&cPath=8&zenid=9i5dg7vdovt76g9kbh7fmpb6h5
> $34.80 with "free shipping".


Hi JR,

Got mine from HobbyKing. They include a 2 pole connector with clips on a red and black wire which you can connect to a battery (must be greater than 5V IIRC). This goes onto the first 2 pins of the 9 pin input (for 8 cells).

It also includes a cable for the USB and a plug for the alarm output.

But if you're going to monitor multiple cells, you must get your own plug. The referenced thread discusses this.

Regards,

major


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## major (Apr 4, 2008)

etischer said:


> Do you have the Digikey part number of the connector you are using?


I'll get back to you on this. I think I keep the P/N with the parts at home in my FrankenBasementLab.


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## major (Apr 4, 2008)

JRP3 said:


> You should be able to run WinXP in Microsoft Virtual machine or VMware within Win7, I think.


Thanks, but I got no idea what you said  Let alone how to do that


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## JRP3 (Mar 7, 2008)

major said:


> Thanks, but I got no idea what you said  Let alone how to do that


Basically it's a program that allows you to run other operating systems within your existing operating system. You may already have it on your Windows 7 PC.
http://www.microsoft.com/windows/virtual-pc/

or

http://www.vmware.com/products/player/

I've never used either but it doesn't seem that difficult.


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## Matthijs (Jun 19, 2009)

Jack Rickard made an earlier show with the celllog 8s here: http://media.ev-tv.me/news011510-1280.mov (1-15-09 show)
He shows the 9 pin connector digikey partnumber: JST XHP-9 connector. Digikey 455-2217ND I think he got the connector and wire from ebay but could not find which store.


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## major (Apr 4, 2008)

etischer said:


> Do you have the Digikey part number of the connector you are using?


JST XHP-9 CONN HOUSING DigiKey #455-2217-ND

JST SXH-001T-P0.6 CONN TERM CRIMP XH 22-28AWG DigiKey #455-1135-1-ND

Right off the bags they came in


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## Amberwolf (May 29, 2009)

Regarding the dead USB on the laptop, if it still has a PC-Card (PCMCIA) or CardBus slot, you could use this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16815104302
http://www.newegg.com/Product/Product.aspx?Item=N82E16839158032
to give you new USB ports.

If it has an ExpressCard (NEWCARD) slot instead, there are also these options:
http://www.newegg.com/Product/Product.aspx?Item=N82E16839150021
http://www.newegg.com/Product/Product.aspx?Item=N82E16839328008

More options:
http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=2030260421 1207413188&name=2 x USB 2.0
http://www.newegg.com/Store/SubCategory.aspx?SubCategory=421&name=Laptop-Add-on-Cards

If you're not sure which slot type you have, post the brand and model of your laptop and I can probably find out on the manufacturer site for you.
________
Plastic bongs


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## JRP3 (Mar 7, 2008)

Does this look like a pre-wired JST XHP9?
http://www.rcaccessory.com/bantame-stationeac131e-stationopenendedwiringharnessforbc-8charger.aspx


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## tomofreno (Mar 3, 2009)

> Does this look like a pre-wired JST XHP9?


 Looks similar, but of course I can't tell if it has the same pin spacing. Pin 1 to pin 9 distance is about 25/32" on mine, which gives about 0.0977" pins spacing, or 2.48mm). I ordered connectors from Digikey like major. Only problem I have had was in connecting one to the cells while AC was connected to the Manzanita un-isolated charger. I dropped a lead from the cell log 8, it touched the metal battery box and killed the cell log 8. Now I ensure there is no AC connected when messing with the cell log 8. Works very well. I have alligator clips on the ends of the leads so I can just clip them onto different groups of cells. I don't leave it on the pack unless I am using it to datalog as I view extra wires as extra opportunity for failure. I soldered my leads into the connector.


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## JRP3 (Mar 7, 2008)

Got my Celllog8S from EPBuddy in 4 days! No connector other than the small 2 lead. I was hoping one of my many computer connectors might line up but no deal so I haven't tested it yet.
I just noticed the connector I linked above only has 8 leads so it's not a JST9.


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## Dolphyn (Nov 17, 2009)

JRP3 said:


> Got my Celllog8S from EPBuddy in 4 days! No connector other than the small 2 lead. I was hoping one of my many computer connectors might line up but no deal so I haven't tested it yet.


A floppy-disk cable will work. 

I'm using a 50-pin connector which works nicely for connecting two CellLog units in one assembly, even if it has a bunch of extra holes.


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## JRP3 (Mar 7, 2008)

Yeah I did some more scrounging and found some other cables. A 40 pin hard drive cable connector lines up too though the cable itself is a little lightweight. These white plugs also work but you have to shave off the outside flanges to use more than one of them so they fit next to each other.


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## CFreeman54 (Jan 14, 2009)

Hi Guys. I just received seven cellog eights I ordered from HobbyKing.com and am thinking about how to wire them. Major had told me: 

"_Anyway, the CellLog8 will monitor 8 cells and is an independent unit (isolated electrically). So for more than 8 cells, you just use multiple CellLog8 units. For 50 cells, you need 7 of them.

I have been testing 14 cell batteries and use two CellLog8s. 7 cells on each. Since each CellLog8 is isolated, you can string as many as you want. Once they are connected to the cells in the pack, the most positive lead on CL#1 is common to the most negative lead on CL#2, and so on. But this causes no harm, unless you plug into the USB on your computer while the CL is connected to the battery. So unplug the CL from the battery before you connect the USB._ "

I am a little confused about _"the most positive lead on CL#1 is common to the most negative lead on CL#2, and so on." _

The Celllog8 users manual says maximum pack voltage of 43 volts can be measured....so if I string two of these to more than 13 cells I will exceed the maximum rated voltage for the device. Isn't that going to fry it? Am I misunderstanding something here? Should my seven cellog 8s just be used as isolated units to measure data from 8 cells per cellog device? I guess the data can be combined for all 50 cells when downloaded to a PC, but I would not have pack voltage readings (which is somewhere around 160 V).


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## major (Apr 4, 2008)

CFreeman54 said:


> I am a little confused about _"the most positive lead on CL#1 is common to the most negative lead on CL#2, and so on." _


Hi CF,

See http://www.diyelectriccar.com/forums/showthread.php/lipo-etractor-44430p2.html post #11. Notice each CellLog (CL) has 9 pins for the cell inputs. The connector I make has 9 wires. Black is the most negative. Red is the most positive. Let's use cell numbers starting with the most negative cell in the pack being cell#1. And cell numbers increasing in the series string as you work towards the most positive cell.

So with my connector, the black wire from CL#1 goes to the negative terminal on cell #1. The purple wire goes to the positive terminal on cell #1. But the purple wire also connects to the negative of cell #2 by virtue of the series power connector. Then the blue wire on CL#1 goes to positive on cell #2. And so on. Then the red wire from CL#1 goes to positive on cell #8. You have 8 cells and 9 wires.

Now when you wire in CL#2, the black wire from CL#2 goes to the negative of cell #9. But the negative of cell #9 is actually common (due to the power connector) to positive of cell #8. Wire CL#2 as before, purple wire to cell #9 positive, blue wire to positive of cell #10, and so on. Finally the red wire from CL#2 goes to positive of cell #16. 

When you wire in CL#3, its black wire to negative of cell #17 will be common to the red wire of CL#2 which was on cell #16 positive (by virtue of the power connector). This continues for as many CellLogs as you use.

Because each CellLog is an isolated unit, each CellLog only sees 8 times cell voltage. In my case that was 4.2 volts per cell max. So each CellLog sees only 33.6 volts maximum, even though multiple CellLogs are connected together in the higher voltage battery pack.

But BEWARE!!!! The USB port and alarm output on the CellLog are not isolated from the cells which connect to the CellLog. So you cannot connect the USB (or alarms) from multiple CellLogs together while those CellLogs are attached to the battery pack. This will cause a high voltage loop and damage, like blowed up CellLogs, melted wires and/or damaged equipment like your computer.

So you MUST disconnect the CellLog from the battery before connecting the USB to the computer to download data. The user manual says you can connect a single CellLog USB to a computer to monitor while it is connected to the battery. But when I did this, with just a single CellLog, it blew the USB in my laptop and in the CellLog also. My advice is to always disconnect from the battery before plugging in the USB.

You have a similar situation with the CellLog alarm output. Not isolated from the battery. So if you want to use the alarm outputs in the application, you must connect each CellLog alarm output to an isolation relay.

I hope that explains it for ya. I have only used CellLogs on my 14 cell Kokam batteries. These reach 56 volts and I have not had problems due to exceeding the 43V max stated for an individual CellLog. I suggest you wire in CL#1, try it. Then CL#2, try both of them. Then CL#3, and so on. 

Good luck and keep us posted 

major


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## CroDriver (Jan 8, 2009)

I have integrated the Cell Log into a plastic box. When it's heated up by the sunlight it reads some low voltages for the 5th and 6th cells evedough I have only 4 cells connected to it. The alarm sound is annoying so I would like to get rid of this. What could cause it?


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## JRP3 (Mar 7, 2008)

You could turn off the alarm completely but I guess you want it for the cells that are connected. Or maybe try a different Cell log unit? These Cell logs do some weird things sometimes, the screen on mine will randomly go almost completely blank once in a while, as if all the contrast is gone, then come back on.  They are neat devices but somewhat glitchy.


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## Dolphyn (Nov 17, 2009)

JRP3 said:


> These Cell logs do some weird things sometimes, the screen on mine will randomly go almost completely blank once in a while, as if all the contrast is gone, then come back on.


One of mine does that, and it has some additional tricks such as turning the display upside down or reversing the display (dark on light background). Its behavior improved a lot after I updated the firmware.


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## EVfun (Mar 14, 2010)

The heat is likely causing component drift or a small thermocouple effect. You could try connecting the unused inputs together and to the last used input. This is using short circuits to force the zero volt issue on the unused inputs. It may or may not clear the problem if the cause is component drift due to heat. 

Adding vents and a fan to the box is another idea. Heat is not good for electronics.


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## CFreeman54 (Jan 14, 2009)

Thanks for the information Major. Would you explain the isolation relay concept a little more? I would like to hook up the alarms for all the cell-logs. 

I wonder if there is some way to isolate the USB port output voltages so the data could be fed to a laptop while monitoring the batteries. The screens on the cell-logs are too small to look at while driving.


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## Amberwolf (May 29, 2009)

A little on the overkill side, but this would work:
http://www.sitech-bitdriver.com/products/Datasheets/2170.pdf

Some others:
http://physicsworld.com/cws/product/P000006153
http://www.bb-elec.com/productsubcat.asp?MainCategoryId=11


Bunch of other hits using this search:
http://www.google.com/search?q=usb+to+fiber+optic+converter
________


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## major (Apr 4, 2008)

CFreeman54 said:


> Thanks for the information Major. Would you explain the isolation relay concept a little more? I would like to hook up the alarms for all the cell-logs.


Maybe http://www.diyelectriccar.com/forums/showthread.php?p=183013#post183013 posts #41 & 43 will help.


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## CFreeman54 (Jan 14, 2009)

Fiber optic media converter to allow data feed to USB port without the voltage! You guys are brilliant! I like this idea. Now I just need time to work on it....after I finish the other electrical wiring on the car. Thanks.


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## FWD (Feb 3, 2012)

JRP3 said:


> You could turn off the alarm completely but I guess you want it for the cells that are connected. Or maybe try a different Cell log unit? These Cell logs do some weird things sometimes, the screen on mine will randomly go almost completely blank once in a while, as if all the contrast is gone, then come back on.  They are neat devices but somewhat glitchy.


sorry for the bump of this old post but i also have the same problem with these cellogs
i have the 8m
the 8S is fine ( at the moment )
is this normal? when the screen blanksout does the device still alarm?


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## rwaudio (May 22, 2008)

FWD said:


> sorry for the bump of this old post but i also have the same problem with these cellogs
> i have the 8m
> the 8S is fine ( at the moment )
> is this normal? when the screen blanksout does the device still alarm?


I have one that the screen does weird things, the alarm does seem to function normally though regardless if the screen was working or not.


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## FWD (Feb 3, 2012)

rwaudio said:


> I have one that the screen does weird things, the alarm does seem to function normally though regardless if the screen was working or not.


ok thx
i have more then one where the screen flips up side down or blanks and then come's back on again.
weird stuff but i read this is normal.. o well happens a lot
as long the alarm output is still working its fine for me


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## zapyourrideguy (Oct 25, 2012)

For monitoring and LVC alarm only to monitor a 24 cell pack of lipo Can i just run a separate alarm from each of 4) cellog8's (6 cells per unit) avoiding something more complicated circuitry wise. Basically just hooking up the 4 celllog 8's in series with the +- common between each group of 6 as described earlier in this post. As long as I pulled the celllog off for data logging? 
pack drain will be more even staying with 6 cells per logger
I would still have to protect the charging end if I'm not around to hear an alarm for HVC. Plan is to eventually install an Orion.
Thanks


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## profg (Jun 2, 2018)

Hate to revive an apparently dead thread but no answer yet so....Don't try cascading them since low side of alarm port is Batt -. Also, really ring out the alarm circuit, and observe port max current and voltage, as it is not a transistor (as shown) but a FET. Will handle a typical auto 50A relay for bat disconnect on LV, HV, etc. alarms. Search for opto isolator mod among others. Very useful device tho.


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## Karter2 (Nov 17, 2011)

Sadly, the very useful Celllog 8, seems to be no longer available through any the usual sources , EBay, RC shops, Hobbyking, Alixpress, etc etc. 
If anybody knows of a source , please post it up.


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## Russco (Dec 23, 2008)

Karter2 said:


> Sadly, the very useful Celllog 8, seems to be no longer available through any the usual sources , EBay, RC shops, Hobbyking, Alixpress, etc etc.
> If anybody knows of a source , please post it up.


Nope, out of production. Need to find something else for LV and HV cell protection. Mini BMS is also out of production. 

I've had 35 years experience with conversions, now driving my sixth personal EV and considering coming out of retirement with a LV/HV BMS that looks and connects similar to the Mini BMS. But, not a copy.


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