Ks,
You are correct, a Li-ion PCB measures what is going in and going out but it only steps in to isolate the battery if its factory-programmed limits are exceeded. Other than that it leaves the battery alone.
This is the PCB in that pack. Note the limits in the specs;
https://www.batteryjunction.com/pcbfor7l...CTU%40xQmn
It will allow up to 5-7A to be drawn from the battery pack before stopping it. LabRadar lists its consumption as 0.8A at 5V, so well within the limits of the PCB. It will also cut off power to the radar when the first cell drops below 2.3V. Any lower and damage to the battery occurs. When I say first cell Li-ion batteries are never exactly the same so some will discharge and age quicker than others. Some have more internal resistance than others. This is why if you have more than one cell after a while the cells will get out of balance. I use a smart charger to balance Li-ion packs every now and then to keep them fresh otherwise they will start to give reduced capacity when there's nothing wrong with them. The charger gives voltage reading for individual cells which I why the white JST plug is on the pack. The red Deans plug is for power in and out and the JST for monitoring the individual cells when charging. If you keep all the cells in your pack balanced you get more life/capacity out of the battery. Commercial USB power packs don't let you do this and this may have been what was wrong with mine. I never pulled it apart so will never know.
Back to Lab Radar. That 2-cell 7.2V Li-ion pack made from 4*18650 laptop batteries is enough power for my 2-hour shooting sessions (total capacity is about 4000mAh). The radar draws more power when it is emitting than when it is on standby and you toggle between the two settings between strings. Like a radio, battery life depends on how much transmitting you do relative to how much it is on but on standby. The radar has two time limits that you can adjust;
I set Arming to the full 300 and Screensaver to 120. If the screen has switched itself off and you fire a shot, as long as it is still Armed then it will wake itself back up again. Once Arming reaches 300secs without a shot being fired it switches itself off. When each shot is fired it re-sets the clock to zero so you can leave it Armed/emitting for longer than 300secs as long as you are still shooting.
You are correct, a Li-ion PCB measures what is going in and going out but it only steps in to isolate the battery if its factory-programmed limits are exceeded. Other than that it leaves the battery alone.
This is the PCB in that pack. Note the limits in the specs;
https://www.batteryjunction.com/pcbfor7l...CTU%40xQmn
It will allow up to 5-7A to be drawn from the battery pack before stopping it. LabRadar lists its consumption as 0.8A at 5V, so well within the limits of the PCB. It will also cut off power to the radar when the first cell drops below 2.3V. Any lower and damage to the battery occurs. When I say first cell Li-ion batteries are never exactly the same so some will discharge and age quicker than others. Some have more internal resistance than others. This is why if you have more than one cell after a while the cells will get out of balance. I use a smart charger to balance Li-ion packs every now and then to keep them fresh otherwise they will start to give reduced capacity when there's nothing wrong with them. The charger gives voltage reading for individual cells which I why the white JST plug is on the pack. The red Deans plug is for power in and out and the JST for monitoring the individual cells when charging. If you keep all the cells in your pack balanced you get more life/capacity out of the battery. Commercial USB power packs don't let you do this and this may have been what was wrong with mine. I never pulled it apart so will never know.
Back to Lab Radar. That 2-cell 7.2V Li-ion pack made from 4*18650 laptop batteries is enough power for my 2-hour shooting sessions (total capacity is about 4000mAh). The radar draws more power when it is emitting than when it is on standby and you toggle between the two settings between strings. Like a radio, battery life depends on how much transmitting you do relative to how much it is on but on standby. The radar has two time limits that you can adjust;
- 'Arming time' (when the radar is emitting, max power draw) = 300 seconds.
- 'Screenaver' (the LED screen is backlit) = 600 seconds.
I set Arming to the full 300 and Screensaver to 120. If the screen has switched itself off and you fire a shot, as long as it is still Armed then it will wake itself back up again. Once Arming reaches 300secs without a shot being fired it switches itself off. When each shot is fired it re-sets the clock to zero so you can leave it Armed/emitting for longer than 300secs as long as you are still shooting.