CellLog 8 hacking
- Thread starter fechter
- Start date
Electronics noob warning...(I apologize in advance)
I am seeing a lot of LiPo users with the CellLog8 and they sound pleased, so I will probably get one. There have been concerns expressed that if left plugged in (example: over winter?) it will drain and damage the pack over time.
Is there a simple on/off switch I can put inline on one of the balance leads so I can turn the cell-log off, without unplugging it? The tiny balance leads concern me if I need to plug and unplug them frequently. Another option I am considering is adding two extra short JST jumpers inline, so that the plug and socket that are plugged-in/un-plugged often, are replaceable when they incur damage from my fat caveman fingers.
I am seeing a lot of LiPo users with the CellLog8 and they sound pleased, so I will probably get one. There have been concerns expressed that if left plugged in (example: over winter?) it will drain and damage the pack over time.
Is there a simple on/off switch I can put inline on one of the balance leads so I can turn the cell-log off, without unplugging it? The tiny balance leads concern me if I need to plug and unplug them frequently. Another option I am considering is adding two extra short JST jumpers inline, so that the plug and socket that are plugged-in/un-plugged often, are replaceable when they incur damage from my fat caveman fingers.
If you disconnect the pack negative to the CellLog, the drain drops to around 400uA on the cells other than the first one. This would still be bad for long term storage.
A PC board mounted connector makes it pretty easy to plug and unplug them, but takes a board. Perf board might work for this.
A PC board mounted connector makes it pretty easy to plug and unplug them, but takes a board. Perf board might work for this.
mr.electric
10 kW
So would you power the relay coil from one of the sense wires and run the coil ground to one of the alarm signal wires. The other alarm signal wire is already grounded so just snip it off?
Here's how I think it should look:
The alarm negative line is redundant, so you could just snip it off.
The diode is not critical, but should be rated for about 1A. It can be soldered directly to the relay pins. Without the diode, the voltage spike from the coil will zap the alarm output transistor.
The resistor value is approximate for a 32v total voltage. It should be 1/2W or more. If you ran the relay off a ~12v tap on the pack, you could eliminate the resistor, but it would unevenly drain the pack if it stayed on for long.
I show the 'typical' throttle cutoff wiring, but you could also use the NC contacts and place the contacts in series with the throttle signal line (and probably not need the 1k resistor on the throttle line). You could also chain multiple CellLogs in series by using this approach.
The alarm negative line is redundant, so you could just snip it off.
The diode is not critical, but should be rated for about 1A. It can be soldered directly to the relay pins. Without the diode, the voltage spike from the coil will zap the alarm output transistor.
The resistor value is approximate for a 32v total voltage. It should be 1/2W or more. If you ran the relay off a ~12v tap on the pack, you could eliminate the resistor, but it would unevenly drain the pack if it stayed on for long.
I show the 'typical' throttle cutoff wiring, but you could also use the NC contacts and place the contacts in series with the throttle signal line (and probably not need the 1k resistor on the throttle line). You could also chain multiple CellLogs in series by using this approach.
Yes.auraslip said:Thanks for the diagram Mr. F!
Like this?
mr.electric
10 kW
I like the N.O. Smaller solid state relay because it is so small and requires no diode. Could I switch the Cell log alarm output to N.C. and connect the N.O. Relay so that it carries the throttle signal. That way if the person who is going to ride this vehicle neglects to plug in the sense wires to the cell log the scooter will not even run.
Danny Mayes
1 kW
spinningmagnets said:
Hey spinningmagnets,
i bought these to do exactly that -
http://www.ebay.com.au/itm/Alps-SPU...al_Components_Supplies_ET&hash=item2308672691
They are only 6 pole of course so only good for 6s but if tha'ts what you are running, they should work a treat
D
Danny Mayes
1 kW
btw, if you want some, i got more than i need (pack of 10, i only need 3 and a spare or 2). Send me a PM w your address and ill send you some.
D
D
auraslip said:
Pretty standard part, but replacing it will be challenging unless you have good smd skills. One way is to use a razor blade to snip off all the legs then use solder wick to remove the leg pieces.
Cells 1 and 2 go directly to the microprocessor. Cells 3-6 go to the 324 and cells 7-8 go to the 358
auraslip
10 MW
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- Mar 5, 2010
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- 3,535
Thanks Fechter. I might destroy it taking it apart, so I'll wait till I get it done before I order the new op-amps.
I'm not bad at SMD work, or maybe I've just been lucky so far. Perhaps this would be a good opportunity to invest in new tools? Like the solder tip that clamps on to both sides of SMD components to ease in removal and installation?
I'm not bad at SMD work, or maybe I've just been lucky so far. Perhaps this would be a good opportunity to invest in new tools? Like the solder tip that clamps on to both sides of SMD components to ease in removal and installation?
Guys, I have CellLog which had 4S battery connected in reverse, so now when connected properly, it boots up and shows Err: Cell volt.
I can clearly see that D3 has been blown, and I can replace it, but now I tried connecting 4-5V to pin 1 and 2 and it doesn't power up at all. So I guess something else smoked when battery was connected in reverse, but I can't see anything else that is burnt aside from D3.
Anybody have idea what else could have been damaged?
I can clearly see that D3 has been blown, and I can replace it, but now I tried connecting 4-5V to pin 1 and 2 and it doesn't power up at all. So I guess something else smoked when battery was connected in reverse, but I can't see anything else that is burnt aside from D3.
Anybody have idea what else could have been damaged?
One more thing I've just noticed. If you connect 2S battery it will boot up and read voltages just fine. If I connect 3S or more (so now voltage is going throught burnt D3) it displays Err: Cell volt. So now I'm puzzled. Obviously something else apart from D3 is damaged because it won't power up on 1S battery, but it boots just fine on 2S and reads correct voltage. :?
bobale said:
Probably half of D2 is also blown or one of the traces going to it. D2 feeds power to the regulator from the cell 1 pin.
I've just checked and you were right, lower part of D2 is also blown.fechter said:
I've just measured D5 resistance, and it's about 200Ohms, so I connected 3S battery and jumped around D3 with 200Ohm resistor, and it stopped showing Err and showed right voltage. So I guess I'll just move D5 to D3 as I only need it to monitor 6S battery.
auraslip
10 MW
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- Messages
- 3,535
Just to confirm - http://www.mouser.com/Search/Refine.aspx?Keyword=BAT54C
this is the diodes on the front end?
And this is the "optocoupler" on the output http://www.mouser.com/Search/Refine.aspx?Keyword=BC817-40
really it appears to be a transistor.
this is the diodes on the front end?
And this is the "optocoupler" on the output http://www.mouser.com/Search/Refine.aspx?Keyword=BC817-40
really it appears to be a transistor.
auraslip said:
Hmmm... where did you get those part numbers?
They would probably work, but I'm not sure how to interpret the markings on the installed parts.
The diodes should probably be rated a bit higher than 30v, but it wouldn't surprise me if that was the stock part rating. In any case, I don't think either of them are critical and about any part that fits and has the right pinout should work.
hillzofvalp
100 kW
I want to be able to get one cell log and cycle through my 21S pack without switching connectors. Any way to do do this cost effectively? I rather just show cell gap by using like 7 LEDs to indicate critical conditions
Also, can this hardware be interfaced easily with an arduino for some expandability?
I suppose it would be easy enough to get the arduino to cycle through single cells, but I'm not sure it will take up to 21 cells.. would have to have a reroute transistor to switch between each half of the
"I have also worked with Atmega1280 and using the 3 available TTL serial ports to monitor and aquire log output from 3x CellLog8 devices (tapped them pre-TTL->USB chip) which gives me up to 8S per channel and still leaves the TTL->USB output to go to real time PC logging... the beauty is I can split the input parameters and quickly evaluate cell voltages to detect both High Voltage and Low Voltage Condition...
The application for both is an ebike LiPo BMS (actually 18-24S3P 15AH) and eventually it will trigger a shunt board durring charging to keep each cell balanced at maximum charge..
One other feature will be a reduced power mode where the throttle input (hall sensor based so 0-4.7v) will be sampled by the Mega and Output back to the controller... if LVC is tripped (can be multiple stages) throttle will be limited to a maximum preset amount - thus limiting current and maintaining cell at LVC to get a bit more low power out of it for limp mode but without risk of damage to the Lipo cells.
Hope it helps!
-Mike" (mwkeefer)
the real question is: can you tap the 8M that doesn't have usb... I presume so.. can anyone verify this?
Also, can this hardware be interfaced easily with an arduino for some expandability?
I suppose it would be easy enough to get the arduino to cycle through single cells, but I'm not sure it will take up to 21 cells.. would have to have a reroute transistor to switch between each half of the
"I have also worked with Atmega1280 and using the 3 available TTL serial ports to monitor and aquire log output from 3x CellLog8 devices (tapped them pre-TTL->USB chip) which gives me up to 8S per channel and still leaves the TTL->USB output to go to real time PC logging... the beauty is I can split the input parameters and quickly evaluate cell voltages to detect both High Voltage and Low Voltage Condition...
The application for both is an ebike LiPo BMS (actually 18-24S3P 15AH) and eventually it will trigger a shunt board durring charging to keep each cell balanced at maximum charge..
One other feature will be a reduced power mode where the throttle input (hall sensor based so 0-4.7v) will be sampled by the Mega and Output back to the controller... if LVC is tripped (can be multiple stages) throttle will be limited to a maximum preset amount - thus limiting current and maintaining cell at LVC to get a bit more low power out of it for limp mode but without risk of damage to the Lipo cells.
Hope it helps!
-Mike" (mwkeefer)
the real question is: can you tap the 8M that doesn't have usb... I presume so.. can anyone verify this?
