Search found 15 matches

by helgeo
Nov 18 2013 4:21pm
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

Thanks for the tip on checkmarking the communication, I noticed that saving of EEPROM data seems to take longer when it is on. Guess there might be some retries taking place? I have now monitored my pack for about two days with idle bleed off, and it is holding its charge well. Have now set bleed lo...
by helgeo
Nov 17 2013 1:17pm
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

I had Idle-bleeding activated and also set minimum bleed voltage to 3.5V. I have a suspicion that the minimum bleed voltage is ignored when idle bleeding is on. I have now tried to turn off the idle bleed and will see if the pack can hold its charge. Will also try to enable idle bleed again and set ...
by helgeo
Nov 15 2013 7:12am
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

I think I may have found another problem with this BMS. A couple of months ago I made a 5Ah 10S lipo pack with integrated BMS. It seemed to work well, charging and balancing was behaving as expected. But last night I checked the pack after it had been unused for a few weeks. It was dead, no power on...
by helgeo
Sep 06 2013 2:35am
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

I made a slight mistake in the previous post. There is an option to enable bleeding in idle/OV condition not idle/OC as I wrote. I enabled it last night and disconnected the charger while 1 of 10 cells was in OV condition, 1 cell was way lower than the rest. Now the status is that 9 cells have volta...
by helgeo
Sep 05 2013 5:10pm
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

I ordered the usb to i2c adapter from bmsbattery.com. Have just connected it to the bms and could immediately see why it cycles the charging at 2 second intervals. The charge over current limit was set to 10A while the actual charge current was around 11A. Changing the limit to 15A made it work imme...
by helgeo
Jun 06 2013 7:10am
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

I have four of these BMS'es, two 12S and two 10S. All preconfigured for LIPO voltages. Have tried one of each, the 12S is working as it should; it charges and balances. The 10S is behaving in the same way as reported by friendly1uk and Knutix. I have followed the connection sequence carefully on bot...
by helgeo
Mar 25 2013 9:52am
Forum: Battery Technology
Topic: O2Micro OZ890 Based BMS Units
Replies: 130
Views: 25878

Re: O2Micro OZ890 Based BMS Units

This is really interesting, I started some development on the BMSBattery BMS last year using a TI USB to I2C adapter that I had from a previous project. Perhaps you could get a bluetooth device for your Arduino and implement a simple serial protocol that relays the i2C messages? This way the BMS cou...
by helgeo
Dec 09 2012 4:30pm
Forum: Battery Technology
Topic: Cheap programmable bms
Replies: 24
Views: 2173

Re: Cheap programmable bms

I see varying reports in the thread some success some disappointment but mostly efforts to engineer a communication cable. The order that everything must be carefully connected and disconnected at pains of blowing up the board is a deal breaker for me. The order of connection and disconnection is o...
by helgeo
Dec 08 2012 4:55pm
Forum: Battery Technology
Topic: Cheap programmable bms
Replies: 24
Views: 2173

Re: Cheap programmable bms

Lots of info on that BMS here:
http://endless-sphere.com/forums/viewtopic.php?t=20971

I have successfully connected to it with a generic usb to i2c adapter. Trying to make my own software for monitoring and configuration.
by helgeo
Dec 06 2012 2:36am
Forum: E-Bike Technical
Topic: Need i2c to Bluetooth converter
Replies: 7
Views: 1948

Re: Need i2c to Bluetooth converter

Thanks Bartimaeus, I just found out the hard way. Received two of the blank PCB's the other day, guess I should read the specs more carefully before ordering next time :oops: A friend of mine just ordered a couple of these: http://dx.com/p/jy-mcu-arduino-bluetooth-wireless-serial-port-module-104299 ...
by helgeo
Nov 22 2012 8:48am
Forum: E-Bike Technical
Topic: Need i2c to Bluetooth converter
Replies: 7
Views: 1948

Re: Need i2c to Bluetooth converter

Thanks for the ideas whereswally606, I'm more into software than hardware so was hoping to find something that does not require too much soldering ;) Perhaps this one will work with an Arduino Nano? http://www.goodluckbuy.com/bluetooth-module-for-micro-controllers-arduino-easy-wireless-serial-uart.h...
by helgeo
Nov 22 2012 3:31am
Forum: E-Bike Technical
Topic: Need i2c to Bluetooth converter
Replies: 7
Views: 1948

Need i2c to Bluetooth converter

I have a couple of BMS'es with OZ890 micro controllers that I plan to use in battery packs for eBikes. The BMS has an i2c interface that can be used to read status from the battery pack. I'm looking for an inexpensive solution to add Bluetooth to the pack so I can create an Android app to monitor th...
by helgeo
Nov 21 2012 10:41am
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

romelec wrote:Here are the datasheets.
Fantastic, thanks :smile:
by helgeo
Nov 21 2012 9:15am
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

OK, I'll respond to my own post :) Found this datasheet for the OZ8920 which seems to be fairly similar to the OZ890: http://wenku.baidu.com/view/54d861f0ba0d4a7302763a3b.html According to that the cell readings are 12 bits and should be multiplied with 2.44mV (5000/2048). That means that my reading...
by helgeo
Nov 20 2012 5:09pm
Forum: Battery Technology
Topic: connections for? EcityP Smart S5-13 BMS
Replies: 187
Views: 49949

Re: connections for? EcityP Smart S5-13 BMS

Hi, I have just bought two of these BMS'es pre-configured for use with 12S Lipo packs. Some initial testing has shown that charging of a pack works well, but when I tried to discharge a single cell down to about 4.10 volts no balancing was taking place. Is this normal behavior? Also I have just mana...