Paul C. Buff, Inc. Technical Forum

Hello all. Hope you can help me decide between the VLX & the Mini..

The wrinkle is.. I have an unusual use case..

I do motorcycle touring.. ( often with a large portion of the trip away from roads ).. And the Vagabond would be a great source of portable power while on the road. ( powering notebook, charging batteries / usb devices.. etc ).. Not to mention it's intended function.. powering strobes...

My dilemma is this. The Mini, is smaller.. Runs on 12v ( so could run it off the bike battery ).. But, it does have a lower AC power output and will recycle my ( 2-4 ) Einsteins slower ( when I'm actually working ) ha!

The VLX. Will recycle my strobes faster ( important.. after all that is the primary function ). But.. it has a size penalty.. ( on the bike, storage is at a premium ). Also, I would need to come up with a more efficient method of charging the battery.. Running a second inverter to power the power brick is wasteful on space and amps ( the bikes stator puts out 17A total )..

So.. Assuming the charging issue for the VLX can be licked ( any suggestions are very welcome ).. What would be your choice in this use case?

The USB port on the VML is .5A, where the VLX is 2A. So if that is important, then the VML may not supply the charge you need.

Much of the secified depth of the VLX is from the stand mount. This means stuff can be packed around it, so its effective size is considerably smaller.


On the other hand, if you are shooting *or* travelling, you can get two VMLs, using two to shoot with for (better recycling than just one), and take one of them on your travels. And you would have a spare battery if you wanted to leave the inverter. But there is a price penalty.

The USB is less of a concern. Plenty of 12V chargers that can be hard wired to the bike.. The charging port is handy when using the VLX off the bike.. But I don't think I would use it 'on the move' just out of concern of damaging the port with a USB cable moving around..

It's Shooting and traveling.. There are occasions I will bring Einsteins with me.. though more often it would be one or the other..

I guess I am leaning towards the VLX. Except for the problem of recharging the ( attached ) internal battery. As I understand it needs a 24v (nominal) DC power source.

So.. to charge it.. I need another 120v ac source ( smaller, cheap square wave inverter? ) to power the power brick.. to charge the internal battery.. There is a size penalty with the VLX.. But that is doubled with the addition of a 2nd inverter & power brick..

I think I would need to consider a 12v to 24v power supply that can be hard wired. ( replacing the 2nd 120v inverter & power brick ) Any advice on what I should look for? Specs or model #'s that are known to work?

I am a tad confused by some of what you say. The only thing you would need a 24VDC supply for would be to run the VLX inverter from the bike, bypassing the battery altogether.

You cannot charge the VML system directly from 12VDC into the 14.8VDC battery, nor can you charge the VLX system directly from a 24VDC system directly to the 25.6VDC battery. But, you can run the inverters from those DC systems.

The VLX battery would require the charger to run from 120VAC, just like the VML's charger. So, if your bike can supply 120VAC and 100W, you can charge either battery. The source of the DC to AC can be anything, the VLX charger does not care, as long as it gets 120VAC.


The charger brick is about the same size for both systems, so that is a wash.

I had not considered using the VLX without the battery.. I assumed the amp requirements of the inverter at full output would make a 12-24v PS impractical. Also, that same amp draw may deplete the motorcycle too rapidly ( or even if left on overnight with some load ).. Can you give me an idea what the amp draw ( at 24v ) would be at max output?



Yes.. I understand this. Am I correct in understanding that a comparative charger/power supply would be necessary for 12v.. and for the VLX it would also be necessary.. but as an addition to a smaller 12-24v converter?



This is what I am trying to avoid.. Having to run a 100w (will square wave work for this? ) inverter to power the power brick/charger.. Not only do the inverter and power brick take up space.. But I also have a very limited amp budget. The bikes electrical system only generates 17a total.. Of course amps are lost in the inverter and the charger.. So, if they can be deleted and a more efficient differential charger can be used I'll be better off.



It is.. except for needing a second inverter to power it.. And also the previously mentioned amp loss in running both..

The max draw would be about 20A


To charge either battery, the charger need to be a comparive charger. We cannot guarantee any charger other than the one we provide. Charger output for VML is nominally 16.8VDC and the output for VLX is nominally 29VDC.



A square wave inverter would be OK to feed the charger.

Ultimately, I think either will be perform well for you. I really cannot vouch for what kind support system will be required for use on the bike, however.

I don't mean to put too fine of a point on this. But is 20A the peak amp draw.. in overload condition like would happen trying to recycle 3-4 Einsteins?



Of course.. I do understand that this is a use case that you have never considered..

The problem of charging the VLX battery is really my sticking point. I've been having trouble finding a 12-24V power supply that also acts as a charger.. At least for a reasonable price. I have found some made to charge motorized wheelchairs from a vehicle but they cost nearly the same as a Mini. Also they are made to charge lead acid batteries.

If you don't mind one more dumb question.. At what (low) voltage will the mini cry out NO MAS! and shut down? I'm wondering if it will shut down ( if left on overnight ) before the motorcycle battery ( running the mini from the motorcycle battery of course ) was depleted to the point where it would not start the bike. ?

The battery draw and output current is the same for one Einstein™ at 1/16 as five Einsteins at 640Ws each (3200Ws). The difference is the current limiting will force the voltage lower and lower during recycle as the load increases. Hence, the recycle time will get longer and longer.

We test each VLX™ with four AB1600s (2560Ws total). They recycle at about 7 seconds. 3200Ws (five 640Ws lights) recycles in about 9 seconds.

We have done any number of "destruction tests" at 2560Ws, firing once every 10 seconds for 30 shots in a row . . . 70% duty cycle. No destruction, no failures, no problems.

Running at 70% duty cycle for 5 minutes continuously is about the maximum recommended usage, as this heats the inverter and battery. When they get too hot, they will temporarily shut down.

We have also done numerous tests at 2560Ws fired every 15 seconds (50% duty cycle) for 60 continuous shots without shut down or excess heat or failure.

Note* although the VLX is rated at 400W continuous (as in a 400W light bulb), during recycle it is outputting about 700W.

Paul.

Thank you very much for the personal response.

Though.. I think you misunderstood the nature of my question.. But in the end you gave me the info I was looking for.

See, I do a lot of motorcycle touring. I'd like to bring a pair of my Einsteins with me to use on the road or at a particular destination. Nighttime, abandoned mining camps.. that sort of stuff.. In addition to these, more normal use cases also are required.

On a motorcycle.. there are 2 particular constraints. Space and Power ( electrical, both capacity & power required to charge the inverters battery ).

What I have found is:

The Mini of course is smaller.. Can be used directly with the bikes 12v battery ( eliminating some space problems ) or if attached battery is used a differential charger can be used to charge it from the bikes supply.. But, I am unsure at what voltage the mini's inverter will shut down. If running the inverter off the motorcycle battery this is very important. I don't want the motorcycles battery run down too far.

The VLX is bigger of course, But offers more nominal wattage. If used with the attached battery I'll need a smaller 12-24v power supply with some sort of comparative function to charge the battery. If run directly from the bikes battery, I will need a 12-24v power supply capable of providing 35A on the 24v side.

Based on the space limitations.. electrical limitations ( The motorcycle only puts out 17A total at 12V ).. I think the VLX with the attached battery will work best for me. But I still have to solve the charging problem for the VLX battery.

The easy way is a cheapo 100W inverter.. to power the power brick that charges the VLX battery.. But space ( and power ) wise that is inefficient.

So.. if you guys ( or anyone ) knows of a 12v (to 24v ) power supply that will charge the VLX battery.. please let me know!

You will need the charger block shipped with the VML or VLX. This has monitoring circuitry that prevents over charging.

A 100W cigarette lighter style adapter will work, if you have that kind of 12V port on the bike.