Question MPPT charge controller and Ecoflow Delta

I have a question for those who know solar battery charging controllers. The Ecoflow Delta 1300 uses the same XT60 input port for both solar charging and for charging from an automobile 12 VDC “cigarette” socket (via an adapter cable). The mfg. states charging time on 4 x 110watt solar panels (in series) as 4 to 8 hours, but 13.5 hours from the car’s 12vdc. The XT60 input is rated 400W 10-65VDC 10A max. If I were to put a suitably sized (say 600 watt) 12VDC to 48VDC converter in the vehicle, could I supply the 48VDC to the Ecoflow’s XT60 input, basically fooling it into thinking there were 4 x 100watt solar panels hooked up in series producing the power? What limits the input current to 10amps - the controller inside the Ecoflow (I assume it’s MPPT) simply limiting current, or does it need to sense voltage drop/rise from the panels to find the max power point, or the MPPT controlling its output to the unit’s internal battery? In other words, will it work with a constant voltage supply from a DC converter? I’d like to hack this to reduce charging time while charging off the vehicle, but not burn up the unit with my dangerous “little bit of knowledge”. This would put approx. 40 amps + converter losses additional load on the vehicle.

Alternatively, my vehicle does have a 250 amp alternator, and I could put in a 1.5 to 2K 120VAC inverter and fast charge the Ecoflow off that on the AC charger in under 2 hours, but have concerns about drawing down the vehicle’s batteries (it would draw from the vehicle’s AGM batteries if only idling) and overtaxing the alternator (even though it’s 250 amp) as the calculated load for the fast charge is 1200watts - 100 amps + inverter losses on the vehicle’s battery/alternator system.

Suggestions please!


The likely reason that it’s longer off the cars cig lighter is the car doesn’t push as much power through and it’s already 12v and likely that port is only built to put out 15 amps max. You’d need to check the fuse. There is probably a buss fuse in the cigarette plug itself if you take it apart.

Your panels however being 440watts and wired in series are probably pushing something like 65V but the amps are considerably lower than the cigarette lighter because of the voltage. My guess is that amperage gets converted after the input by the charge controller and then passed to the battery. Thus the difference in charging times. As an example at my panels it’s only 3-4 amps in full sun but that translates to 15-20 amps after the conversion.

My advice would be to contact the manufacturer about adding an isolator and charging directly from the battery. It sounds like they have a solution for that already with the inverter? Or is this something you made up? These all in one devices are tough, you can’t alter any of the components as you can in a standard electrical system.

Also, don’t idle your car to charge your batteries. The only reason to idle a vehicle ever, is if you are at a stop sign or you are warming up a vehicle pre ECU. 1 minute is like driving 2 miles so you’re talking 120 miles worth of driving to charge a battery at idle.i

Well, I talked with an EE on another forum, and he confirmed my suspicions. The Ecoflow charges roughly 3 times as fast on 3 solar panels 36v x 10a = 360w, and 4 times as fast on 4 solar panels 48v x 10a = 480watts, as opposed to 12v x 10a = 120w from a 12VDC vehicle '“cigarette lighter socket”. Solar panels run most efficiently at less than their open circuit voltage but a 12VDC vehicle battery would supply (relatively) infinite current until it very quickly blew the 15 or 20 amp “lighter socket” fuse. Given a fixed voltage supply (the vehicle’s 12VDC electrical system), current flow is determined by the load (resistance), hence, the Ecoflow MUST be controlling/limiting the current at 10 amps, regardless of the input voltage (provided it is within its operating range).

I am no EE, but I was always under the impression the amps were what mattered not the watts. 10 amps is 10 amps regardless of voltage. I would still assume there is a conversion happening after the input to convert the 48v to 12v, which would up the amperage considerably, hence the faster charging times? I am confused on the voltage or maybe I have no clue, but according to my app in full sun with three 100 watt panels they run near 60v not 36v.

Still it sounds like if you use an isolator you’re still stuck with 10 amps at 12v because it’s regulated at the input?

I ran through the history on my panels and I have rarely gone past 250w, typically ~180w on average over the last few months. You should only plan on getting half of what they are saying out of the panels. They are great, but I have never seen them hit their specs at 100%. Off of my panels I have seen 20 amps in full sun and in summer, but typically ~15 or less in full sun.

My system has run for 443 days, charged fully 905 times, created 19179ah total, and generated 248.088kW. Super cool to be able to look back and see those stats.


Here in the USA, amps are the normal measurement for DC power, and watts are normal for AC power, with the exception that fuses & circuit breakers are usually rated for both amps and voltage.

BTU’s are typically used for heating & cooling power.


“Everything should be made as simple as possible." ~ Einstein