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Battery discharging too quickly #32

Open jvillagomez opened 5 years ago

jvillagomez commented 5 years ago

I bought the 8000mAh battery hoping to get long hours out of it, but it discharges too quickly. I only get about 90 minutes out of it before FSSD (3.6V -> 3.0V).,

The pico board is set to the correct profile and we charge it with 5V 3A charger. No tasks or gui is running. Just logging.

Board: UPS Pico HV3.0A Stack Plus

Battery: LiFePO4 3.2V Capacity: 8000 mAh

discharge_case4

PiModules commented 5 years ago

Hi,

It is depending what current you are drawing form the system on battery powering.

It should be running on 3V long time as the 3V is nominal voltage for this battery chemistry, it is very flat on this value

Please leave it until system automatically shut down, due to low battery

Please do the calculations as described in the manual, PAGE 96 https://drive.google.com/file/d/1-qsnRpp6tYCa9hC7_SYldHXyOm-1pYLi/view

On 10/6/2018 8:43 AM, Juan Antonio Villagomez wrote:

I bought the 8000mAh battery hoping to get long hours out of it, but it discharges too quickly. I only get about 90 minutes out of it before FSSD (3.6V -> 3.0V).,

The pico board is set to the correct profile and we charge it with 5V 3A charger.

Board: UPS Pico HV3.0A Stack Plus

Battery: LiFePO4 3.2V Capacity: 8000 mAh

discharge_case4 https://user-images.githubusercontent.com/12376228/46567860-01a38500-c8f0-11e8-8484-e7a9fe28a1d7.jpg

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jvillagomez commented 5 years ago

Hello! Sorry for the lengthy response. I had to step away from this work for a while. But I followed your steps above and did the calculations.

So running nothing absolutely nothing except the logging task, I should be getting just over 4hrs of battery runtime. Still a heavy deviation away from the average 90 minutes I’m currently getting.

I ran over 10 tests and the all average just over 90 minutes, as depicted in the graph.

Expected = 4 hrs 10 minutes Actual= 1 hr 30 minutes minutes

Processes Running = Log

The low battery threshold is set to 2.9V but shuts down mostly at 3V. Out of 10 cases, the battery only went to 2.9V twice.

The average time I am getting, with the battery at 3V is 20 seconds only. Then FSSD initiates.

I have attached my calculations below. I also attached a text file with all running processes. The text file all the way at the bottom is called "top.txt".

current_calc

top.txt

jvillagomez commented 5 years ago

Hi PiModules, The order number for my Pico and 8000mAh battery is #206153747055