Jackery 300 - Using and Charging at the same time

[tertius]

Her's what I'm doing:
- Fridge in car + Jackery for camping to power the fridge when stationary.

I haven't decided on the capacity yet, so ignore that for now.

I want to know if I can run the fridge off the Jackery while charging it with Solar? I'm seeing people say the manufacturer says not to do this. This would really be a deal killer and I'd probably need to get a E1000 instead. (Needing 45-50 hours of battery for the fridge).

 

[tertius]

Okay, pass-through charging is what it's called. I've seen this before but my question is a bit more nuaned.

Will the device draw from the batteries if what the solar gets isn't enough? Or will it only pull from one source. I.e. if solar isn't enough it will pull all power from the battery?

 

[snoobler]

I can't speak to the jackery specifically, but most systems behave as follows: You have loads and inputs. If your PV power exceeds your loads, it should charge the battery with the surplus. If your loads exceed your PV power, the batteries will be drained.

 

[Bob142]

I can't speak to the jackery specifically

I can. I've got a couple 240s and a 500. As expected, they behave exactly as you describe.

 

[tertius]

I can't speak to the jackery specifically, but most systems behave as follows: You have loads and inputs. If your PV power exceeds your loads, it should charge the battery with the surplus. If your loads exceed your PV power, the batteries will be drained.

So the power output (when exceeding PV) will be battery + PV or can't it do more than one power source to an output at the same time?

 

[Bob142]

So the power output will be battery + PV or can't it do more than one power source to an output at the same time?

The power output is limited by the specific output port you are using. See their published specs.

The Jackery will manage delivering the power as @snoobler described. Beyond that I'm not clear on what you are asking/concerned about.

 

[snoobler]

So the power output will be battery + PV or can't it do more than one power source to an output at the same time?

While it seems like it, there isn't really a difference. Loads pull from battery cables - always. Solar is feeding the battery. If the battery is at its set voltage (floating, fully charged, whatever), the current from solar effectively bypasses the battery through its own wires to supply the loads.

If the battery is at a lower voltage and not fully charged/floating, but are less than the solar, the solar current is both charging the battery and supplying the power for the loads through the battery cables.

 

[tertius]

While it seems like it, there isn't really a difference. Loads pull from battery cables - always. Solar is feeding the battery. If the battery is at its set voltage (floating, fully charged, whatever), the current from solar effectively bypasses the battery through its own wires to supply the loads.

If the battery is at a lower voltage and not fully charged/floating, but are less than the solar, the solar current is both charging the battery and supplying the power for the loads through the battery cables.

Perfect. Thank you for the specific answers.

 

[OnTheRoadAgain]

a little interesting tidbit about this......

If you are simultaneously draining and charging the battery Kirchhoff's current law predicts the results.

I always thought that doing both at the same time would overheat the battery but as far as the battery is concerned, it just takes whatever excess current is available.

If the outgoing load draws 1 amp and your incoming supply current is 2 amps, the battery will charge at 1 amp while the circuit continues to power the load.

If your load is drawing 5 amps and your current source us supplying 3 amps, your battery will drain at the rate of 2 amps

So the only way to overheat the battery is to supply an excess current per the batteries specs above the amps draw of the load.