Am I able the to charge and discharge the battery at the same time?

[Reggiereg36]

I have 1 eg4 6500ex, 1 eg4 lifepo4 battery, 1k watts of solar. My system is 100% off grid and located in my garage. I mainly you my system to power my portable a/c when I am in the garage working out. When I am charging my batteries and turn on my portable ac, the batteries stop charging when the a/c compressor turns on. I called signature solar and I was told that I cant charge and discharge the batteries at the same time. I just wanted to confirm this. If this is true that means I cant run any loads while I am charging? Is there any way around this?

Any input would be appreciated.

 

[42OhmsPA]

I have 1 eg4 6500ex, 1 eg4 lifepo4 battery, 1k watts of solar. My system is 100% off grid and located in my garage. I mainly you my system to power my portable a/c when I am in the garage working out. When I am charging my batteries and turn on my portable ac, the batteries stop charging when the a/c compressor turns on. I called signature solar and I was told that I cant charge and discharge the batteries at the same time. I just wanted to confirm this. If this is true that means I cant run any loads while I am charging? Is there any way around this?

Any input would be appreciated.

Edit - @sunshine_eggo makes more sense and is correct. See his post below.

Say what?
You can use the system just like you describe.
If you're loads exceed your PV power available you will pull from the batteries for the difference.
Example.
Your making 1000w with your panels, your putting 900w into your batteries after inefficiencies, you turn on a load that uses 1200 watts, your batteries will supply 300 watts, if your load was 700w you'd reduce your charging to 200w.

Make sense?

 

[sunshine_eggo]

I have 1 eg4 6500ex, 1 eg4 lifepo4 battery, 1k watts of solar. My system is 100% off grid and located in my garage. I mainly you my system to power my portable a/c when I am in the garage working out. When I am charging my batteries and turn on my portable ac, the batteries stop charging when the a/c compressor turns on. I called signature solar and I was told that I cant charge and discharge the batteries at the same time. I just wanted to confirm this. If this is true that means I cant run any loads while I am charging? Is there any way around this?

Any input would be appreciated.

Your question is wrong.

No. You can't charge a battery and discharge it at the same time. Current can only go one direction with a battery. You are either charging, discharging or neither.

Can the SYSTEM charge the battery while powering loads? Youbetcha, but your loads have to be lower than your PV input.

1kW of solar is likely very marginal for being able to run the A/C, so what is likely happening is that your A/C is using MORE than the PV can provide, i.e., the PV is providing a portion of the needed power, and the battery is providing the rest.

It helps to understand that a 1kW array RARELY puts out 1000W, and it only does so in near perfect conditions at noon. Your array will more typically deliver 700-800W peak assuming they are facing due south, optimally tilted for your latitude, and you have absolutely no shading of any kind from sunrise to sunset. Your power production will look similar to:



Additionally, the inverter itself draws about 80W continuously, so if you leave it on, it's going to gobble about 38% of your battery's capacity over 24 hours. About 40% of your array is also dedicated to replenishing the lost energy consumed by the inverter.

 

[42OhmsPA]

Say what?
You can use the system just like you describe.
If you're loads exceed your PV power available you will pull from the batteries for the difference.
Example.
Your making 1000w with your panels, your putting 900w into your batteries after inefficiencies, you turn on a load that uses 1200 watts, your batteries will supply 300 watts, if your load was 700w you'd reduce your charging to 200w.

Make sense?

Remember that saying a photo is worth 1000 words...

 

[Reggiereg36]

Say what?
You can use the system just like you describe.
If you're loads exceed your PV power available you will pull from the batteries for the difference.
Example.
Your making 1000w with your panels, your putting 900w into your batteries after inefficiencies, you turn on a load that uses 1200 watts, your batteries will supply 300 watts, if your load was 700w you'd reduce your charging to 200w.

Make sense?

That makes sense. Now that I think about it my the pull from the a/c was 1300 watts and the panels were only were only producing about 800 watts. That's why it stopped showing that it was charging because it was going to powering the load.

Thank you for breaking it down.

 

[Reggiereg36]

Your question is wrong.

No. You can't charge a battery and discharge it at the same time. Current can only go one direction with a battery. You are either charging, discharging or neither.

Can the SYSTEM charge the battery while powering loads? Youbetcha, but your loads have to be lower than your PV input.

1kW of solar is likely very marginal for being able to run the A/C, so what is likely happening is that your A/C is using MORE than the PV can provide, i.e., the PV is providing a portion of the needed power, and the battery is providing the rest.

It helps to understand that a 1kW array RARELY puts out 1000W, and it only does so in near perfect conditions at noon. Your array will more typically deliver 700-800W peak assuming they are facing due south, optimally tilted for your latitude, and you have absolutely no shading of any kind from sunrise to sunset. Your power production will look similar to:

View attachment 153872

Additionally, the inverter itself draws about 80W continuously, so if you leave it on, it's going to gobble about 38% of your battery's capacity over 24 hours. About 40% of your array is also dedicated to replenishing the lost energy consumed by the inverter.

Thank you for you help.

 

[JohnnyBravo]

hello guys, I won't open a new thread about same issue. So, are you saying that the fan in order to work it must consume less power than the panel (100W in this case) would produce? See picture:

 

[ShaneC]

hello guys, I won't open a new thread about same issue. So, are you saying that the fan in order to work it must consume less power than the panel (100W in this case) would produce? See picture:

So long as there is capacity in the battery the extra power needed will come from there. Say the fan uses 100w but the panels only give 60w, that means 40w will come from the battery. Once the battery runs out then I'm not sure exactly what will happen. Possibly the AC voltage will lower or the inverter will turn off due to not being able to provide the power needed. Depends on the inverter.

 

[JohnnyBravo]

so it means, the battery won't be charged at all but the current coming out of the panels via PWM/MPPT will be used by the fan/consumer together with the needed current from the battery by discharging it? All this is controlled by the PWM/MPPT or by the BMS?

 

[DIYrich]

so it means, the battery won't be charged at all but the current coming out of the panels via PWM/MPPT will be used by the fan/consumer together with the needed current from the battery by discharging it? All this is controlled by the PWM/MPPT or by the BMS?

Controlled by the physics. When the fan draws more watts than the panels can provide, the voltage drops. It will continue to drop until it reaches the voltage of the battery. At that point, the battery starts contributing.

Similar in reverse if panel produces excess watts. If voltage is higher than what load draws down, the higher voltage can be added to the battery.

 

[JohnnyBravo]

In this case, can you tell the applicability of the LOAD slots from a PWM instead of connecting the load directly to the battery?

 

[DIYrich]

In this case, can you tell the applicability of the LOAD slots from a PWM instead of connecting the load directly to the battery?

I'm guessing the pwm takes higher voltage from the mppt and drops it down to battery voltage.

 

[JohnnyBravo]

I don't understand, my question is about the purpose of the LOAD connection to a PWM / MPPT instead of connecting directly to the battery, see these connection ports

 

[sunshine_eggo]

The purpose of the load ports are to power small DC loads. The controller usually has additional options to turn the load ports on and off based on either battery voltage or time of day.

The load ports are always at battery voltage.

 

[JohnnyBravo]

found some answers here: https://diysolarforum.com/threads/d...e load directly to,damage of the battery life.

 

[JohnnyBravo]

hmm another issue, my wires that come from my 10A PWM to the battery are thin. If I want to use a load that draws 150A from my battery, do I have to change the wires from PWM to the battery or it's enough to use proper wires between the battery and my inverter?

 

[DIYrich]

hmm another issue, my wires that come from my 10A PWM to the battery are thin. If I want to use a load that draws 150A from my battery, do I have to change the wires from PWM to the battery or it's enough to use proper wires between the battery and my inverter?

power from battery to inverter should not be going through the Charge Controller. Wire from Charge Controller to the Battery is sized for the Charging current.

 

[ShaneC]

Do not connect any heavy load like the inverter to the SCC Load output. They are usually only capable of low current output. Connect the battery with wire to a busbar, then the inverter and the SCC separately to the busbar using appropriate wire for each. Calculate the maximum draw from the battery, it sounds like 150A for the inverter and use that for sizing the wire from battery to busbar.

 

[hicke]

hmm another issue, my wires that come from my 10A PWM to the battery are thin. If I want to use a load that draws 150A from my battery, do I have to change the wires from PWM to the battery or it's enough to use proper wires between the battery and my inverter?

A load pulls current from a power source. The load will never know what other things are connected to the battery. You should also match your inverter and battery to the planned AC loads and the battery max amp draw.

 

[Hank Waconda]

I am able to charge and invert at the same time as I use separate inverter, charger & CC's. All components have separate cables to battery buss bar. It is a simple system that just chugs along From -20F to 100F with no interaction except watering the batteries 4 times a year or starting up small inverter gen if it has been cloudy for days. No BMS, software updates or problems. 5 years now. KISS