[TwoUptons]

Hi All,

I just received a pair of Godox MS300V strobes for my birthday (well, one, the other is on order).

I'd like to use them outside as well as inside, but I'm having a hard time figuring out how much power I would need to run them (and I got the ones with the LED modeling lights for this reason).

I haven't been able to figure out exactly how much power the units draw, though they are only 300 W/s with a 10 W modeling lamp, so it shouldn't be too much. They have a 5 A fuse as my only real hint... but that's also the same fuse that works with the older units with the 150 W halogen modeling lamp, so in theory it should be less than 4 A.

If I assume they actually draw 5 A each, that would imply I need about 1000 W available continuously from the power bank. That is a ton of power to run a couple of strobes... and power banks that can put out that level of power are big, heavy, and expensive.

Paul C Buff sells a battery that can run up to 3200 W/s of their lighting with 120 W of power... so either the Buff units are insanely more efficient than the Godox, or the Godox don't normally pull anywhere near 5 A.

Has anyone tested these to see how much power they actually pull? I'd be really pleased if I could get away with a 300 W power bank or similar. That would be excellent for location shooting...

Thanks,

-Eric

[Bob 256]

A better indicator of what size power bank you're going to need is the number of shots you take at each use along with the output needed for each shot. You might purchase a relatively inexpensive Kill-A-Watt meter and use it to determine both the peak wattage needed (right after a shot) and the total Watt-hour demand after a given shooting session. When you take a shot, the current (and thus the wattage) will jump to its highest value while the capacitors in your flash recharge. After that, the wattage will drop to some lower value (mostly being the consumption of your modeling lights). These individual peaks result in a given amount of Watt-hours being drawn for the entire shoot and that is what is used to size a power bank along with its capacity to handle the peaks.

If you go with a 300W power bank, it may indeed be able to handle the peaks, but you might find that you only get a limited number of flash recycles out of it. You don't want your power bank going dead during a shoot and you don't really want to take its lithium battery down full way each time as that will decrease the life of your power bank. Shoot (no pun intended) for a bank that will only lose around 50-70% of its capacity during a shooting session and you should be ok. Keep in mind that a power bank will last longer with fewer deep discharge cycles and that its capacity will eventually decrease with the number of discharge cycles (another specification to consider in buying one).

One other thing here. When you say "power bank" you may be talking about a battery bank designed for your flash system. What I'm talking about above also applies to that, but nowadays, you can purchase fairly low cost "power banks" (often incorrectly referred to as a "generator") which contain a lithium battery bank and have a 110VAC outlet (internal inverter). The latter can work well if your flash accepts 110VAC power and might even be more cost effective than a flash system battery (plus they have several 12 Volt and 5 Volt charger utility outlets in addition to the 110VAC power). Just make sure the one you buy will handle the peak power demand and has a capacity (Watt-Hours) to get you through your longest anticipated shooting session.

P3 P4400 Kill A Watt Electricity Usage Monitor


https://www.amazon.com/Jackery-Generator-Compatible-SolarSagas-Emergencies/d...dDbGljaz10cnVl

Good shooting with your new flashes.

[AstroDave]

I second Bob's Kill-a-Watt gizmo - exceedingly handy to have around the house (well, I guess if you are a power geek like me).

As to that 5 amp fuse - that almost certainly is somewhat, to much, higher than the peak current draw. A fuse is generally designed/in there for protection in case of hardware failure. It would be poor design to rate it close to the typical current draw.

[bobbotron]

I’ve powered one godox ms300 with the smallest jackery solar generator, they don’t take that much juice imo!

[TwoUptons]

I am definitely looking at one of the standalone power banks sold by any number of companies.
I'd also like to use it as something to run lights and a fan around the house if we lose power during a storm, for example. It would also be nice for camping.

What I've noticed when reading the specs is that the batteries have a wide range of maximum allowed current draw for a similar total capacity (and the other way around).
Godox sells a 192 Wh battery, for example, that can handle 750 W continuous or 1400 W peak. B&H sells them for $1,000 plus $340 per additional battery pack.
I think the Paul Buff units are doing something similar -- high current for not a lot of total capacity, though they don't post their complete specs.
And for strobes it's fine to focus on current not total capacity since they aren't pulling much most of the time.

For $1,000 from Jackery I can get three 1,000 W outlets and 1,000 Wh, so four times the total power of the Godox and plenty of peak capacity (though it is a much larger/heavier unit).
And Amazon can have a Jackery 293 Wh unit to my house tomorrow for $300, which is more my speed, but it only provides 300 W of power continuous.

I suspect the MS300V is probably around a 2.5-3W thing, to keep it well away from its fuse limit (though the fact Godox shipped it with two spare fuses suggests popping them is not terribly uncommon). That would suggest to me something with 400 W per outlet is plenty, but I don't want to break things finding out.
I guess the Kill-A-Watt is the only way to know for sure.

-Eric

[West Penn]

If a DIY approach is something you'd consider, you can build a unit that can meet your power needs for a lot less. I have a set-up for powering a pellet stove insert in the event of a power outage during the colder months. I built my set-up in 2010 for about $125, but it's about twice that today. I did however replaced my battery last month as it wasn't holding a charge.

My set-up is a type 27DC (deep cycle) Marine battery (about a $100 today from Walmart), a 750 watt continuous/1500 peak watts modified sine-wave inverter (about $75 from Harbor Freight), a battery charger (about $75 from Harbor Freight), and a battery box (about $20 from Walmart). The downside is that it's heavy as it's a lead acid battery, about 50 pounds alone. And, it's a bulky. None of which are a problem for my use. For portability, you could add a small dolly/hand truck.

You could substitute a larger modified sine wave inverter, say a 1000 watt continuous/2000 peak watts, for a few more dollars. Also, some electronics require a pure sine wave inverter and I have no idea if your lights fall into this category. The pure sine wave inverter is about $200 at Harbor Freight.

I'd guess you could use a smaller battery, such as a deep cycle trolling motor battery or a lawn tractor battery, either of which would be much lighter and more compact as well. How well one of these smaller batteries would hold up to you power needs, I couldn't say.

Also, a trickle charger can be used to keep the battery fully charged when not in use, but you still need to use a regular battery charger after draining the battery somewhat through use.

[Bob 256]

Note: If you're interested in a Jackery, go to their website. They run specials from time to time. I got my Jackery 300W power box for $210 with a new customer discount. Nice little unit which has a rated 300 watts continuous with 500W short term peak AC output. It comes with a wall charger which is probably the fastest way to recharge it. I use it for astronomy and not flash power, but 110VAC is 110VAC (and it's sinewave output so can work with most any equipment). Think they're having an Easter weekend sale but not sure what's covered in terms of sale items.

https://www.jackery.com/

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Last edited by Bob 256; 04-09-2023 at 05:25 PM.

[TwoUptons]

The Kill-a-Watt arrived today...

In my quick testing with the light...
245 VA maximum during a charge cycle (just the modeling light and whatever 'top-off' it does varied between 30-50 VA)
175 W maximum during a charge cycle (just the modeling light and whatever 'top-off' it does varied between 17-31 VA)
2.03 A maximum during a charge cycle
I'll note the Kill-A-Watt has like a 1 hz refresh rate, so I may be missing peaks, but these were the maximums of a couple dozen charge cycles.
The Godox was at full power with the modeling light on the whole time to try and maximize power draw.

So what does this tell me? At the most basic, it seems 500 W is enough... and 300 W (with a surge to 500) may be enough.
I'm not sure about the difference here between Volt-Amps (VA) and Watts (W).
The way the Kill-A-Watt works is that Watts are Watts, but Volt-Amps are Voltsrms*Ampsrms.
I don't know what that means to me, though it seems the VA are handling better the peaky nature of the power draw, so I think that is the number I should use.
If nothing else, it would be the conservative answer...

Any other insight is appreciated...

-Eric

[TwoUptons]

Another intermediate update...

The second Godox arrived today, so I tried them both simultaneously connected to the Kill-A-Watt.

Just sitting there the pair pull about 15 VA to keep the displays on.
Running the modeling lights ends up somewhere between 50 and 70 VA, with occasional excursions to 80, which is about double the single unit.

Varying the modeling light does vary the current, so I may look into that if it becomes relevant (which I doubt).
In the charge cycle, from both lights being fired at the same time, the most I saw was about 480 VA, but usually the display stayed at around 300 VA.
I think this is due to the peaky nature of the draw and the slow refresh of the Kill-A-Watt display...
I think, then, this does not change my conclusions from two weeks ago at all... 500 W is enough... and 300 W (with a surge to 500) may be enough, based on what I've seen.

I found a sale on a 500 W battery... (with a surge to 1000 W). We'll see how that goes...

-Eric

[TwoUptons]

And another update...

Bought an EcoFlow River 2 battery. About 500 Wh, 500 W (1000 surge) output, 2 'grounded' 3-prong 120 V outlets. 6 kg.
Interestingly, it basically has a Kill-o-Watt built into it... with about the same 1 hZ response.

Fired up both lights for about two dozen full power flashes. No problems.
Once, the Watt meter got up to 739 W, but only once. The rest of the time it stayed below 450 W, usually below 400 W.
I think this is also the peaky nature of how the lights recycle.

I look forward to trying it with a camera connected

-Eric

[rml63]

Am I to take from this thread that my Jackery 300 explorer could power a Godox MS300?