I need to monitor 48V battery, please advise

[binu G]

Battery Cell monitoring

Hi,
i need to monitor 48V battery health, 24 cells split in to 4 zone.
this will be 12Volt in each channel, need to monitor the cells for health.

please suggest.

i will for sure have a controller and a Modbus interface.
but the analog side i need to have a low cost solution.

Binu G

 

[karesz]

Battery Cell monitoring

Hi,
check for LTCs new "stacked battery monitor IC", I think up to 3-400V!
K.
I have it yet:
www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1003,C1037,C1786,P90340

 

[binu G]

This will be a expensive solution.

Binu G

 

[karesz]

Aha,
What is "expensive " for you pls? Did you checked for hes price and datasheet?
You need only one IC not some pro cell!!
Battery fault monitor handles 12 series-connected cells Samples, demonstration boards and the data sheet for the LTC6801 are now available. Prices start at $4.48 each in 1000-piece quantities. ...(www.eetasia.com)
K.

 

[mikersia]

AMS -> AS8500
AD -> ADuC7036
Maxim -> DS2438

 

[binu G]

I need to monitor VRL battery for telecom application.

BinuG

 

[karesz]

Hi binu G,
Sorry, what is VRL?
Maybe these table helps for you?

http://cds.linear.com/docs/Solutions Manual/Battery_Management_Solutions_PowerPath.pdf
I think, that their are all the others no alternatives because you can not stack their...
Maybe you must built it self with lot of (windows) comparators & such daQ chip after their i.e. the proposed AS.. or ADuc, but for me is than better some simpler ADC system to select....
K.

 

[binu G]

its VRLA

valve-regulated lead-acid

Binu G

Added after 1 minutes:

what if i use a differential amplifier to check each zone and use a microcontroller to log it. will differential amplifiers will work for high input voltages !!

 

[karesz]

OK, you have to select some instrumentations amps, with (ev. onchip)attenuators at the inputs...
I remember for some types from BurrBrown yet Ti & ADI, and an older Appl Note from Jim Williams overa switched/charged capacitor sampler. I applyed it so 17 years ago for max. 250V on the Inputs...
K.

Added after 3 hours 36 minutes:

Hoi Binu G,
I think, I found an Application Note what can be your bible...
Good Luck!
K.

 

[binu G]

hi,
great, this application note is slightly different than what iam looking for. actually i need to monitor each zone and using the controller i have to report with zone is bad, i may have to even change the set voltage at which i need to trigger that the a particular zone is bad.

Binu G

 

[karesz]

Hi,
I thank/belief that you can take surly some ideas for concrete realisations from it...
Did you checkd these II topic pls?:
Battery monitor IC,4 voltages for NoteBookBattery_www.edaboard.com_ftopic140860.html
K.

 

[karesz]

Hi,
Maybe their are good idea-sources for your (SW)realisation too...
K.

 

[binu G]

my requiremement is typical, this is for telecom industry and the specification calls for monitoring the battery though the existing controller. the only media between the battery monitoring and controller is a modbus.

Binu G

 

[pranam77]

Re: Battery Cell monitoring

need to monitor the cells for health. please suggest.

Could you expand this quote?...In the sense how you need to monitor the said VRLA batteries? You need to monitor only the volatge of the batteries or even the remaining power capacity of the same?

 

[binu G]

well,
48V Vrla battery will have 24 Cells, the customer is interested to know which Cell is damaged. ideally i will need to monitor each cell voltage differentially. how ever i got a flexibility in grouping 6 Cells to form one Zone, so that you will need to monitor 8 Zone, if any of the zone voltage run below 6V or a specified Voltage ( configurable ) then that zone should be alarmed for replacement.

 

[pranam77]

For just monitoring volatge, you may employ Digital Pannel meters calibrated to the required scale OR use a LM3914 to see the volatge levels on LED bar-graph. For accurate measuring with load, you may refer to "Smart Battery capacity meter" Or "Battery condition tester" projects published in Silicon chip Magazines...Sorry...dont ask me for the articles..I dont have it..Cheers