Serial EEPROM for safe LiPo charging

[TMorita]

I was thinking about how to build a safer Lipo charger the other day, when it hit me...we need serial EEPROMs on the lipo packs.

You store various characteristics on the serial EEPROM:

chemistry
number of cells in series
pack capacity
max charger current
etc.

...then you have a special charger with a few extra wires for the serial EEPROM and voila...

Now the charger can automatically figure out how to charge the battery pack safely! No more problems with people keying in the wrong charge rate or number of cells in parallel!

Toshi

[Comatose]

An RFID tag might be cheaper. At least thats what "they" would want you to believe.

[sesat]

The SMBus battery/charger interface is used in laptop packs. Maxim makes inexpensive chips whose values can be programmed.


Ram.

[Mr.RC-CAM]

...then you have a special charger with a few extra wires for the serial EEPROM and voila...There is good selection of battery fuel gauging IC's out there that do all that and MUCH more. These are found on cell phone and notebook PC packs. Some fuel gauging chips even have "one-wire" interfaces, so the unused pin on a standard 3-pin R/C battery connector is a perfect match.

The chip used in this R/C battery monitoring project is one example of the Battery Fuel Gauging chip apps that are out there: http://www.digitalproductsco.com/batmon/ . It uses the Dallas DS2438. A data sheet to this nifty part is also at the site.

RC-CAM

[MX]

I was thinking about how to build a safer Lipo charger the other day, when it hit me...we need serial EEPROMs on the lipo packs.

You store various characteristics on the serial EEPROM:

chemistry
number of cells in series
pack capacity
max charger current
etc.

...then you have a special charger with a few extra wires for the serial EEPROM and voila...

Now the charger can automatically figure out how to charge the battery pack safely! No more problems with people keying in the wrong charge rate or number of cells in parallel!

Toshi

A few hardwired jumpers could do it. Serial eeprom would be useful if you wanted the pack to keep track of how many charge cycles and such.

MX

[hul]

Schulze uses a resistor for charge current (1 ohm per mA) and a jumper for battery type (LiIon/LiPo) in the balancing cable:
http://www.schulze-elektronik-gmbh.com/lipoc-e.htm
number of cells in series can be measured by the charger on packs with balancing connections.

keep it simple...

Hans