Li-Time DC/DC Charger still applies float voltage

[Omkar]

We have the Li-Time 40Amp DC/DC charger. After the charge cycle is completed - 14.6V, the charger continues to apply a constant voltage of 14.6V This is what their charge graph implies. We confirmed with a DVM on the output. Not what I expected to see with this charger. Would rather see the charger terminate voltage upon completion. The specs on the charger are titled, "Charging Voltage Limits" We reached out to LI-Time, and here's the core of their response:

"LFP batteries have high chemical stability and are able to safely maintain voltage at full charge without the need to maintain voltage through float charging. Therefore, LFP batteries do not require a float charging process like lead-acid batteries because they have been designed and managed with a balance of safety and performance in mind. It has been technically confirmed that the charger is a constant voltage output and maintaining 14.6V after charging has no effect on the battery."

We are going to charge up our LFP battery again to confirm there is no current flowing into the battery after charge cycle is complete. Seems Li-Time needs a tech editor to avoid confusion.

Welcome any thoughts on this.

 

[time2roll]

Use the standard setting.

 

[mikefitz]

Welcome any thoughts on this.

14.6 volts is almost certain to cause cell overvolts and cause the BMS to shut down the charge path. If you monitor charge current you will see a sudden fall to zero current. It's the battery BMS terminating the charge, not the charger.
The better designed DC to DC chargers allow user control of charge voltages.

 

[Omkar]

Use the standard setting.

I considered that, wanted the float to be at 13.4 (3.35/cell). I need to see how much current is flowing at the standard setting float of 13.5V Thanks for chiming in.

 

[Omkar]

14.6 volts is almost certain to cause cell overvolts and cause the BMS to shut down the charge path. If you monitor charge current you will see a sudden fall to zero current. It's the battery BMS terminating the charge, not the charger.
The better designed DC to DC chargers allow user control of charge voltages.

Yes, I watched the charge current drop off just below 11amps. I was considering a KISAE DMT1230 30A DC/DC controller, programmable charge, tail-current sense, float, and it will restart a charge cycle at 12.5V. Also has a built-in MPPT controller.