Power bank charging

[matt7powell]

I see bluetti, Perron, and eco flow have brought to market specialist dc chargers for power banks to get over the 120 watt max limit from a standard 12v cigarette lighter outlet. If I combine the output of two 12v outlets in parallel, one from van circuit and the second from the leisure circuit, is this a cheap way to charge at over 200 watts? Is it feasible and what would I need to consider to do it safely?

 

[Deaky]

I’d be worried that if one battery had a higher SOC than the other you’d potentially be dumping a load of amps down a wholly inappropriate cable

 

[Pauly]

Yeah, not sure how you could do that
Would need some kind of dual input interface to combine them without electrically joining them ?

 

[Stay Frosty]

Never cross the beams.

 

[Stay Frosty]

Yeah, not sure how you could do that
Would need some kind of dual input interface to combine them without electrically joining them ?

Like a B2B charger...

 

[The Bear78]

Does a B2B combine two inputs to create a higher current output?

 

[Padders]

I use one of these not cheap but well worth it,handy for jump start also

 

[Stay Frosty]

I reckon that's about right, my Renogy DCC50S takes a solar input too, mixes that 21 volts in and spurts out up to 50A at about 14 volts into the Roamer Seat Base battery.

 

[n10n]

I reckon that's about right, my Renogy DCC50S takes a solar input too, mixes that 21 volts in and spurts out up to 50A at about 14 volts into the Roamer Seat Base battery.

Now that you mention it, I used to sometimes feed 12V/10A power supply into CTEK 250SA solar input and get it to charge leisure battery at about 7.5A. But I didn't ever do it with engine running so not sure if it would have actually combined solar and starter battery feeds.

 

[Dellmassive]

I see bluetti, Perron, and eco flow have brought to market specialist dc chargers for power banks to get over the 120 watt max limit from a standard 12v cigarette lighter outlet. If I combine the output of two 12v outlets in parallel, one from van circuit and the second from the leisure circuit, is this a cheap way to charge at over 200 watts? Is it feasible and what would I need to consider to do it safely?

You can do this......

But the caveat is that you need the PPP to have dual inputs.... Ie twin mppts.

That way you can connect one to the starter side and the second input to the leisure battery.

For example the ecoflow delta2 only has one DC charge input.

But the ecoflow delta2 max has twin inputs.

It's the same with the delta3, the standard unit has one input, but the max version has twin inputs.

Anker and Bluetti follow the same path.

So if your unit has twin inputs can can do it..... If not and you only have a single input then you need the alternator power charger..... Which is normally 600-800w so the best idea anyway.