superpanda
Electrical
- May 8, 2009
- 5
I wonder if anyone has experience using LiFePO4 packs under this scenario and can share any comments...
I want to use a LiFe pack as a power buffer/reserve between a CV source (current limited and @ 13 volts) and a load. The load operates at low current when idle, but has periodic bursts of high current when active. The CV source has enough current to cover the low current idle state, but during the bursts of high current the battery will supply the additional power. When back in idle state the CV source will charge the battery.
Also of note...the CV source would not be available all the time. Basically I'm describing an automotive application where the car is only running periodically. Figure a 10% duty cycle.
So, the questions are:
1. Is it appropriate CV charge a LiFePO4 pack in this manner. I don't need a full charge and am not concerned with getting a full charge quickly so I believe I can do without the CC stage.
2. I assume it's ok the CV source is not always connected because if the battery needs more charge when connected then it will draw more current up to the limit. In other words, in the above scenario the battery will not ultimately die as long as the CV source can replace the current that is being used during the time its charging.
3. Will the lower charge of the pack(13v) add to the life of the cells? It should right? Is 12v better than 13v?
I appreciate this scenario is without actual figures. I could add them, but first I'm trying to see if in principal this scenario is OK with LiFe's.
Thanks -AP
I want to use a LiFe pack as a power buffer/reserve between a CV source (current limited and @ 13 volts) and a load. The load operates at low current when idle, but has periodic bursts of high current when active. The CV source has enough current to cover the low current idle state, but during the bursts of high current the battery will supply the additional power. When back in idle state the CV source will charge the battery.
Also of note...the CV source would not be available all the time. Basically I'm describing an automotive application where the car is only running periodically. Figure a 10% duty cycle.
So, the questions are:
1. Is it appropriate CV charge a LiFePO4 pack in this manner. I don't need a full charge and am not concerned with getting a full charge quickly so I believe I can do without the CC stage.
2. I assume it's ok the CV source is not always connected because if the battery needs more charge when connected then it will draw more current up to the limit. In other words, in the above scenario the battery will not ultimately die as long as the CV source can replace the current that is being used during the time its charging.
3. Will the lower charge of the pack(13v) add to the life of the cells? It should right? Is 12v better than 13v?
I appreciate this scenario is without actual figures. I could add them, but first I'm trying to see if in principal this scenario is OK with LiFe's.
Thanks -AP