BQ78PL116

David Are you referring to a UPS system? If so, yes we have a lot of customers using the device for this type of system. The PL116 and PL102 devices can be configured to support up to 16 series cells. If you can send more information, then we may be able to offer a better recommendation. Best regards Tom

Thomas thank you for your reply. The Tripple inverter is for medical carts and I was told that it is the Slave. The BQ3050 which I  was told can be both the Master or the Slave, where as the PL116 is only the Master.  We just want to confirm that we will have the same communication success if we were switch to the PL116.  

There are two issues we are having with the BQ3050:

The fuel gauge goes only up to 32Ah which the battery pack is 40Ah.

A battery pack this size needs Active Cell Balancing not Passive 

Please let us know your thoughts.

Thomas thank you for your reply. The Tripple inverter is for medical carts and I was told that it is the Slave. TheBQ3050 which I  was told can be both the Master or the Slave, where as the PL116 is only the Master.  We just want to confirm that we will have the same communication success if we were switch to the PL116.  

There are two issues we are having with the BQ3050:

The fuel gauge goes only up to 32Ah which the battery pack is 40Ah.

A battery pack this size needs Active Cell Balancing not Passive 

Please let us know your thoughts.

David,

The PL116 can serve as the slave as well. the SMBus communications protocol should be the same on both of them. The bq3050 does not offer active cell balancing, but it is probably a simpler device to use. What is your cell chemistry? The bq3050 may be a better fit, if you are using LiFePO4, because the measurement system on the PL116 is rated down to 2.75V minimum cell voltage.

Regards

Tom

Hi Tom,

It is great to hear that the PL116 can serve as the slave as well.  We are using LiFePO4 lithium cells.  We want to us the PL116 because of its active balancing and a battery pack this size would get better cycle life with active balancing.  The battery pack with the bq3050 doesn't get us more than 1,500 cycles.

You had mentioned that the measurement system on the PL116 is rated down to 2.75V minmum cell voltage, is there a way to adjust that so LiFePO4 works well with PL116. What would you suggest us to do?

Thanks again,

David

Hi Tom,

It is great to hear that the PL116 can serve as the slave as well.  We are using LiFePO4 lithium cells.  We want to us the PL116 because of its active balancing and a battery pack this size would get better cycle life with active balancing.  The battery pack with the bq3050 doesn't get us more than 1,500 cycles.

You had mentioned that the measurement system on the PL116 is rated down to 2.75V minmum cell voltage, is there a way to adjust that so LiFePO4 works well with PL116. What would you suggest us to do?

Thanks again,

David

David,

The 2.75V datasheet value is due to hardware limitations. It should be okay to set the thresholds above 2.8V, because the cell voltage drop-off on LiFePO4 batteries is very steep in this range and the usable capacity can be small depending on your load current requirements.

Regards
Tom

Hi Tom,

Thank you for the follow up.  The 12V40Ah battery module will be discharging at a maximum 150W and charge at maximum of 20A (.5C ).  Will the new chip affect the battery's performance.  What would be the usable capacity for a 12V40Ah with the BQ116 chip.

Thanks and awaiting your reply.

David

David, 

The device should not affect the battery's performance. I cannot answer how much usable capacity you will have. You will have to look at the discharge curves in the battery datasheet to see the estimate based on current and cut-off point.

Regards

Tom