Extending runtime of a small power station

[Jason Dunkin]

Howdy internet folks
Im trying to see if this setup will work for me. I have 2 powerstations, powerstation 1 gets charged by solar and gets 100% charged by noon. Power station 2 gets charged via power station 1's 12VDC cigarette lighter port (like a daisy chain). Powerstation 2 is only 265Wh, also gets charged 100% quickly . Powerstation 2 draws about 8.2 A when charging and charges at about 99W. The appliances that connect to the smaller powerstation 2 are only small DC applicances that draw less than 80W . I was thinking about adding 2 external 12v 100Ah batteries in parallel to increase the runtime of powerstation 2. The 2 12v lifepo4 batteries would be charged using a dc-dc charger (https://www.bioennopower.com/produc...eries-bpc-1503car?_pos=1&_fid=c65b7db7d&_ss=c) and in turn the 2 batteries will connect to the smaller powerstation 1 to charge it. If I get the lifepo4 batteries with builtin BMS then that should get overcharge and undercharge protection.
Will this setup work to extend the runtime of powerstation 2 by adding external lifepo4 batteries ?

 

[Andrewr05]

Yes, within reason any solar input port can accept batteries instead.
I have yet to come across one that didn't.

You cannot charge the batteries that you are running in parallel to 24 volts with a 12V charger though unless you plan on completely disconnecting the parallel connections and individually charging them at 12 volts each time.

Otherwise you would need to get a 24V charger.

 

[Jason Dunkin]

Andrewr05
I thought with me connecting the 12V batteries in parallel would keep the voltage to 12V as I'm not connecting them in series ?

 

[Andrewr05]

Andrewr05
I thought with me connecting the 12V batteries in parallel would keep the voltage to 12V as I'm not connecting them in series ?

I'm dumb, sorry, yes you are correct.

I just quickly glanced and assumed that you were trying to get the power station to charge quicker by running them at 24V.

Which, if your power station can accept a 24-volt input would be a good idea anyways.

 

[Jason Dunkin]

If the battery does not have BMS then is the lifepo4 charger stop charging the battery once its full ?
or do I need to get a battery that includes BMS to protect it from over charging ?

 

[Andrewr05]

If the battery does not have BMS then is the lifepo4 charger stop charging the battery once its full ?
or do I need to get a battery that includes BMS to protect it from over charging ?

Almost every battery that you buy should have a BMS.

And as long as you get a decent enough charger it should have built in "smart" features to turn off on its own once you get to the right voltage.

 

[Jason Dunkin]

Almost every battery that you buy should have a BMS.

And as long as you get a decent enough charger it should have built in "smart" features to turn off on its own once you get to the right voltage.

Thank you.