Splitting solar power for our new Bluetti AC180 and our leisure battery

[andy greenwood]

This section of the Victron manual will help.

5. Configuration and settings

www.victronenergy.com

I suspect the jumper will be on by default but I'm not sure on which profile, probably the first (pin 1 to 2 bridged)

The first profile will essentially prioritise charging the Bluetti, so the LOAD terminal will be on until the leisure battery is essentially flat. The low voltage cutoff there is very low and you probably shouldn't rely on it if your leisure battery is lead acid.

The second profile will essentially prioritise the leisure battery so the LOAD terminal will only be on when the leisure battery is reasonably well charged and there is generation. That's probably the one to start with. AFAIK the algorithm for the LOAD terminal is driven entirely by battery voltage not by solar input, so I'd expect this to also switch on when your battery is being charged from the engine even if it's dark.

If you want finer control remove the jumper and you can do custom settings in the app.

I want to keep the leisure battery as priority, I will charge the Bluetti @ home before setting off on a trip, I'm hoping that it would last a few days at a festival but if it runs low, I obviously want to re-charge it off the Victron.

 

[andy greenwood]

This section of the Victron manual will help.

5. Configuration and settings

www.victronenergy.com

I suspect the jumper will be on by default but I'm not sure on which profile, probably the first (pin 1 to 2 bridged)

The first profile will essentially prioritise charging the Bluetti, so the LOAD terminal will be on until the leisure battery is essentially flat. The low voltage cutoff there is very low and you probably shouldn't rely on it if your leisure battery is lead acid.

The second profile will essentially prioritise the leisure battery so the LOAD terminal will only be on when the leisure battery is reasonably well charged and there is generation. That's probably the one to start with. AFAIK the algorithm for the LOAD terminal is driven entirely by battery voltage not by solar input, so I'd expect this to also switch on when your battery is being charged from the engine even if it's dark.

If you want finer control remove the jumper and you can do custom settings in the app.

I'll check later but i'm sure i removed the jumper when i installed the victron. If i connect to it bia Bluetooth my current LOAD settings are "operation mode - battery life".

 

[roadtripper]

I'll check later but i'm sure i removed the jumper when i installed the victron. If i connect to it bia Bluetooth my current LOAD settings are "operation mode - battery life".

If you did then you have full control in the app but "Battery Life" is likely not a good fit for your use, it's more designed to adapt the load settings for long term off-grid use to avoid killing the battery, for instance lighting in a remote barn.

You should be able to pick one of the 2 defaults mentioned in the App, or set up your own.

5. Configuration and settings

www.victronenergy.com

 

[andy greenwood]

If you did then you have full control in the app but "Battery Life" is likely not a good fit for your use, it's more designed to adapt the load settings for long term off-grid use to avoid killing the battery, for instance lighting in a remote barn.

You should be able to pick one of the 2 defaults mentioned in the App, or set up your own.

5. Configuration and settings

www.victronenergy.com

I'm thinking of trying this one and see how I get on.......

Conventional algorithm

low voltage disconnect: 11.1V

Automatic load reconnect voltage: 13.1V

 

[roadtripper]

What type of leisure battery do you have?

That profile will be very harsh on your battery, I'd recommend the other default one for your expected use.

 

[andy greenwood]

What type of leisure battery do you have?

That profile will be very harsh on your battery, I'd recommend the other default one for your expected use.

ok, I'll try the other setting.

our leisure battery is an .....XTreme 110AH deep cycle AGM ( part number XR1750DC )

 

[andy greenwood]

What type of leisure battery do you have?

That profile will be very harsh on your battery, I'd recommend the other default one for your expected use.

Hi again , apologises for a silly question but am I understanding this correctly ?
If my leisure battery is less than 11.8 v then the load output is OFF.
If my leisure battery is about 14v then the load output is ON.

Conventional algorithm 2:

12V system: OFF when Vbatt < 11.8V, ON when Vbatt > 14.0V.

 

[roadtripper]

Yep, it has hysteresis, think of them as switching actions not a state.

So it will switch the load output on when your battery goes over 14.0v (so likely near fully charged and being charged)

It will then stay on until the battery falls to 11.8v and that voltage will switch the load output off.

It will then stay off until the voltage rises over 14.0v again.

 

[andy greenwood]

Yep, it has hysteresis, think of them as switching actions not a state.

So it will switch the load output on when your battery goes over 14.0v (so likely near fully charged and being charged)

It will then stay on until the battery falls to 11.8v and that voltage will switch the load output off.

It will then stay off until the voltage rises over 14.0v again.

Thank you very much

 

[andy greenwood]

Yep, it has hysteresis, think of them as switching actions not a state.

So it will switch the load output on when your battery goes over 14.0v (so likely near fully charged and being charged)

It will then stay on until the battery falls to 11.8v and that voltage will switch the load output off.

It will then stay off until the voltage rises over 14.0v again.

Hi , I tried charging the bluetti yesterday with the setting on........

Conventional algorithm 2:

12V system: OFF when Vbatt < 11.8V, ON when Vbatt > 14.0V.

i watched it for maybe 15 minutes and the leisure battery voltage kept dropping and dropping and the bluetti charge only went up by about 1 or 2% , it's a guess but I imagine that within an hour the battery would have been flat. It's not what I expected to see, I thought the leisure battery voltage would barely drop as all the power from the solar would be going to the Bluetti ? it was a cloudy day though so the solar wasn't brilliant. Am I missing something or am I expecting too much ?

 

[roadtripper]

Hi , I tried charging the bluetti yesterday with the setting on........

Conventional algorithm 2:

12V system: OFF when Vbatt < 11.8V, ON when Vbatt > 14.0V.

i watched it for maybe 15 minutes and the leisure battery voltage kept dropping and dropping and the bluetti charge only went up by about 1 or 2% , it's a guess but I imagine that within an hour the battery would have been flat. It's not what I expected to see, I thought the leisure battery voltage would barely drop as all the power from the solar would be going to the Bluetti ? it was a cloudy day though so the solar wasn't brilliant. Am I missing something or am I expecting too much ?

No you are not diverting power here, you are you are caching power in the leisure battery and then using that to charge the Bluetti. The load terminals are a simple on/off it's not possible to throttle it to "spare solar only"

The leisure battery would not have been run flat as the load terminals would have turned off at 11.8v (approximately 50%) and then would not have turned on again until the solar (or other charging) had got the battery to 14v

If you want to prioritise the charge in the leisure battery a little more then use a custom profile with a higher OFF voltage. Just be aware not to set it too close to the ON voltage - they have to be reasonably far apart as a 10A load like the Bluetti will drop the voltage anyway and if that drops below the OFF voltage it will just cycle on and off quite rapidly.

 

[andy greenwood]

No you are not diverting power here, you are you are caching power in the leisure battery and then using that to charge the Bluetti. The load terminals are a simple on/off it's not possible to throttle it to "spare solar only"

The leisure battery would not have been run flat as the load terminals would have turned off at 11.8v (approximately 50%) and then would not have turned on again until the solar (or other charging) had got the battery to 14v

If you want to prioritise the charge in the leisure battery a little more then use a custom profile with a higher OFF voltage. Just be aware not to set it too close to the ON voltage - they have to be reasonably far apart as a 10A load like the Bluetti will drop the voltage anyway and if that drops below the OFF voltage it will just cycle on and off quite rapidly.

Ah ok, I've misunderstood how things are working, much appreciated, I'll give it another go.

 

[andy greenwood]

No you are not diverting power here, you are you are caching power in the leisure battery and then using that to charge the Bluetti. The load terminals are a simple on/off it's not possible to throttle it to "spare solar only"

The leisure battery would not have been run flat as the load terminals would have turned off at 11.8v (approximately 50%) and then would not have turned on again until the solar (or other charging) had got the battery to 14v

If you want to prioritise the charge in the leisure battery a little more then use a custom profile with a higher OFF voltage. Just be aware not to set it too close to the ON voltage - they have to be reasonably far apart as a 10A load like the Bluetti will drop the voltage anyway and if that drops below the OFF voltage it will just cycle on and off quite rapidly.

I was hoping to save myself £299 by not having to buy the Bluetti PV200 fold out solar panel if I could have charged the Ac180 via the Load outputs on the Victron, I'm thinking that it may take a long time though to charge the ac180 via the load outputs so may have to buy the PV200 anyway.

 

[andy greenwood]

No you are not diverting power here, you are you are caching power in the leisure battery and then using that to charge the Bluetti. The load terminals are a simple on/off it's not possible to throttle it to "spare solar only"

The leisure battery would not have been run flat as the load terminals would have turned off at 11.8v (approximately 50%) and then would not have turned on again until the solar (or other charging) had got the battery to 14v

If you want to prioritise the charge in the leisure battery a little more then use a custom profile with a higher OFF voltage. Just be aware not to set it too close to the ON voltage - they have to be reasonably far apart as a 10A load like the Bluetti will drop the voltage anyway and if that drops below the OFF voltage it will just cycle on and off quite rapidly.

Is there a set time period that the battery has to be under 11.8v because I've had it lower than that and it hasn't switched the load off ?

 

[roadtripper]

I was hoping to save myself £299 by not having to buy the Bluetti PV200 fold out solar panel if I could have charged the Ac180 via the Load outputs on the Victron, I'm thinking that it may take a long time though to charge the ac180 via the load outputs so may have to buy the PV200 anyway.

Slightly different solutions to different issues. Getting additional panels will increase your generation when you can deploy them but you may not be comfortable leaving your panels (and maybe the pack) outside the van when you are not there. So still useful to have an alternative based on your in van equipment and the programmable load terminals are a little know but useful benefit of the MPPT controllers.

You also don't need to get the same brand panels - just make sure the Open Circuit Voltage is compatible. I use the basic 1002 folding Renogy one with my smaller Bluetti

If you have Amazon Prime it's prime day for the next 2 days that may drop the prices in your favour.

 

[roadtripper]

Is there a set time period that the battery has to be under 11.8v because I've had it lower than that and it hasn't switched the load off ?

I suspect there is some time delay (2 minutes) to stop transient effects toggling the relay but I don't know for certain as my MPPT is still in the box waiting for me to start the solar shed project.

I'd try setting the OFF to something like 12.4 - which is around 75% - to prioritise the leisure battery a little more.

 

[andy greenwood]

Slightly different solutions to different issues. Getting additional panels will increase your generation when you can deploy them but you may not be comfortable leaving your panels (and maybe the pack) outside the van when you are not there. So still useful to have an alternative based on your in van equipment and the programmable load terminals are a little know but useful benefit of the MPPT controllers.

You also don't need to get the same brand panels - just make sure the Open Circuit Voltage is compatible. I use the basic 1002 folding Renogy one with my smaller Bluetti

If you have Amazon Prime it's prime day for the next 2 days that may drop the prices in your favour.

I'll have a look at Renogy, my bluetti is 60v max open circuit voltage

 

[roadtripper]

I'll have a look at Renogy, my bluetti is 60v max open circuit voltage

That's decent headroom and you should be fine with most 100/200W panels - if you can afford the price and space 60v gives you the option of running 2 sets in series to really push charge into the power pack