Buck or boost for charging a battery

[f123]

If I have a deep cycle battery and I want to charge it using MPPT method from the solar panel. There will be some time in a day where the voltage from the solar panel will be less than the voltage of battery, in this case the buck converter will not work? and maybe this will make current flow in the opposite direction damaging the solar panel. Do we have to maybe use buck-boost converter instead?

 

[davenn]

using MPPT method from the solar panel

and maybe this will make current flow in the opposite direction damaging the solar panel.

You should use a decent MPPT controller that has built in reverse current protection ... any good unit will have it

 

[f123]

You should use a decent MPPT controller that has built in reverse current protection ... any good unit will have it

Thank you for ur answer, I will be designing this MPPT controller and will consider the reverse current protection. but I want to know the best option for cases where the output voltage is less than the input, which creates a problem here. Maybe in using buck-boost with MPPT method? but I am not sure if it is possible or not

 

[davenn]

Maybe in using buck-boost with MPPT method? but I am not sure if it is possible or not

that would require some fancy switching for it to detect input voltage level
tho they may exist, I don't know if a buck-boost unit that will do that

 

[f123]

that would require some fancy switching for it to detect input voltage level
tho they may exist, I don't know if a buck-boost unit that will do that

I think I have to do more research about this.

Thank you, davenn for ur answers

 

[(*steve*)]

If you use a flyback inverting topology it won't matter if the panel voltage is higher or lower than the battery voltage.

 

[davenn]

I think I have to do more research about this.

always a good thing you may end up finding it better to buy than build ?

Thank you, davenn for ur answers

you are welcome

come back in the future and let us know how you got on

 

[f123]

If you use a flyback inverting topology it won't matter if the panel voltage is higher or lower than the battery voltage.

is it because the flyback converter is a Buck-Boost converter ?

 

[(*steve*)]

The key point is "inverting". This allows you to do buck or boost with a very simple topology.

 

[f123]

The key point is "inverting". This allows you to do buck or boost with a very simple topology.

Thank you steve!