Convert BQ25650 MPPT board to higher current?

[aquaaddict]

Hi,

Looking at using these MPPT boards eBay auction: #122513080856 for charging battery on a boat from 2x100w panels, of course 200w is more than 5A, so other than using one board per panel and combining the outputs (doesn't seem like a good idea), I was really wondering if they can be upgraded to handle a higher current. My thinking is to put another pair of FETs in parallel with the existing ones (mount them both off board on heatsinks and hardwire to handle current) halve the resistance of the current sense resistor and swap the the inductor out for a higher current version of the inductance.

Any thoughts as to whether this would work or would other components (e.g. the inductance of the inductor) also need changing as I dont know enough about buck systems to know if its a silly idea.

Here is the data sheet of the BQ25650 http://www.ti.com/lit/gpn/bq24650

And here is a selection of application notes http://www.ti.com/product/BQ24650/technicaldocuments

Thanks

Anthony

 

[fourtytwo42]

Hi Anthony,

There are loads of products on there for higher currents including MPPT 10A, 20A even 30A so why do you want to modify a 5A one instead of buy something more suitable ?

Maybe you have already bought it or upgraded your panels ?