Charging priority

[Thebeeman]

Our batteries are still storing the bit of solar that we would have exported previously so it's a bit of a win so far. Since fitting them, on 1/8/22, we've exported 1 Kw and I think that's down to a glitch in the inverter system. If you have PV I would power them up to catch any 'spare' solar for later use.

[Ken]

Sorry not read the manual but if there is a CT clamp on the batts led to the HW diverter then if a current is detected to batts the HW diverter will kick in and heat the HW in preference.

I can really see the problem when one has PV/HW, EV, and batts and trying to work out the priority.

I always think it is easiest to get the PV/HW to work because that will work on any excess but the EV needs 1.4kw min and if one puts a similar restriction on the batts, say only charging when there is 200W excess the PV/HW will always work first, or uses the above.

However i would like to see the PV/HW start in the morning, switch to EV when 1.4kw + exists and then back to PH/HW in late afternoon which is doable. So where does the household batts come in ? perhaps just when the EV is not present or otherwise at night ? So then the question is how to charge the house batts only when the car is not there.

For most this quetion gets worse because their PV is not really big enough to power all those loads in the first place.

10 yrs ago we were just trying to work out how to use PV to do HW. and now look. It can only get more complicated when one has a Heat Pump (HP)

[Oldgreybeard]

Sorry not read the manual but if there is a CT clamp on the batts led to the HW diverter then if a current is detected to batts the HW diverter will kick in and heat the HW in preference.

I can really see the problem when one has PV/HW, EV, and batts and trying to work out the priority.

I always think it is easiest to get the PV/HW to work because that will work on any excess but the EV needs 1.4kw min and if one puts a similar restriction on the batts, say only charging when there is 200W excess the PV/HW will always work first, or uses the above.

However i would like to see the PV/HW start in the morning, switch to EV when 1.4kw + exists and then back to PH/HW in late afternoon which is doable. So where does the household batts come in ? perhaps just when the EV is not present or otherwise at night ? So then the question is how to charge the house batts only when the car is not there.

For most this quetion gets worse because their PV is not really big enough to power all those loads in the first place.

10 yrs ago we were just trying to work out how to use PV to do HW. and now look. It can only get more complicated when one has a Heat Pump (HP)

It does get more complicated the more devices are used, for sure. We have PV, battery storage, thermal storage for hot water and a heat pump!

AFAIK the only PV diverter unit available off-the-shelf that has the versatility to operate with several other loads and set the priority of each is the Eddi, at least it was when I was looking to solve this problem when I installed batteries. These are the options it allows, if sensors are added so it knows about other loads or generation sources (I had to add two extra sensors, one for the PV system, one for the battery system):

Eddi manual page 21.jpg (63.11 KiB) Viewed 564 times