question

dspectrum avatar image
dspectrum asked

Single-battery mobile system with alternator and solar charger together

This is for a truck with no auxiliary battery, just one lead-acid battery,

Would like to add solar system for auxiliary charging. Both charging systems (solar, alternator) will not be active at same time. Can the charge controller and the alternator both be connected directly to the battery, much as solar and AC chargers are?

Do I need a charge relay or some other isolator?

Charger selected is MPPT 75 | 15.

Thank you.

MPPT Controllers
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

1 Answer
jwfrary avatar image
jwfrary answered ·

Yes you can connect the two to the battery at the same time, appropriate fusing to be used however. They can both be operated at the same time. The mppt will just shutdown when the voltage threshold is crossed depending on what you set it to. You can consult ‘wiring unlimited’ for guidance on the wiring.

Alternators work at a slightly lower voltage than chargers do.

if your using this battery I’m guessing for starting, and auxiliary loads, you might consider a battery protect to cut your domestic loads and protect your ability to start the engine.

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

jwfrary avatar image jwfrary commented ·

Of course you can use the load port on the mppt as well if the loads are modest.

0 Likes 0 ·