Paul C. Buff, Inc. Technical Forum

I just received my VML and I read in the manual about connecting external batteries via Anderson connectors. I found this cable http://www.powerwerx.com/adapter-cables ... apter.html . Will I experience any problems using it?

If I use this to plug into the charging connectors will it charge the Lithium battery and/or provide additional current to speed recycle time or just add power to increase longevity of the VML lithium.

Would I get better results if I plug them in parallel despite the power storage variances of the different battery types?

That cable would be fine to run the inveter from a car battery (or similar). The voltage of the VML battery is higher than that of a typical SLA, and therefore cannot be charged in that manner. Also, you do not want to intall the VML battery and the SLA battery simultaneously. If you have multiple VML batteries or multiple SLA batteries in parallel, it would not increase the recycle time, however, it will lengthen the run time. We do not recommend paralleling SLA batteries, and only paralleling VML batteries if they are both fully charged.

So is the correct way to increase runtime to charge both Vagabond Mini batteries, have one installed and plug the other one using an Anderson connector into the front of the inverter?

Yes.

I hope it's kosher to bump this old thread, but it seems like the most relevant to my question. I'm actually more interested in having an SLA, such as the ones from small UPS units, as a cheap backup for an Einstein. You can get a 12V 7ah SLA from Amazon for under $15 shipped, and with a charger and the needed wiring, a spare emergency battery would cost about $30, or roughly ⅓ the cost of an extra VML battery. And the wiring and charger can be reused indefinitely so there would only be a recurring cost of $15 every so often to replace the battery itself. Does such a battery even provide enough juice to power an Einstein at all, much less for at least a few dozen full power shots or more considering the VML is rated at 14.8V @ 8.8 ah? A slightly larger current 12V SLA can be had for marginally higher cost, maybe that would be better? If not, then the whole thing is moot. These small SLAs are heavier than a LiPo but certainly more portable than the car battery sized ones that would clearly provide enough power. I'm not willing to haul around a car battery as a backup!

If there is some merit to such a setup can I use a cable like this one http://www.powerwerx.com/adapter-cables ... e-6ft.html and lop off the rings and replace them with the needed spade connectors?

Secondly, apropos to the original question from this thread, I would like to clarify another question for myself that was not specifically addressed in the manual and that is whether the included charger can be connected while the unit is in use? The manual says the unit should be turned off to charge the battery, but it doesn't say whether this is just to achieve the most efficient charging performance or whether there is some specific danger or contraindication to this type of connection. For example, I have a generic Adorama Flashpoint 600Ws strobe for which I have a NiMH battery pack and the instructions clearly state multiple times that the unit cannot be powered on and charging at the same time due to electrical hazards. I'm guessing that due to the potential heat generated from charging coupled with the heat from sue might warrant similar caution, but there are no such warnings in the VML manual, aside from the aforementioned subdued instruction to "power off" before charging.

Thanks for any help!

If you can get a battery that can provide 30A of continuous power, then a 7Ah battery will be fine. Larger batteries are more likely to be able to provide this type of power.

Also note, the charger that is included with the VML is designed to charge the VML lithium battery. It will not properly charge an SLA battery. You should source a stand alone SLA battery charger.

When using a VML with lithium battery and supplied charger, you can use the VML while charging. This will allow extended run times when using a light in 220V areas, or provide a cleaner power source in questionable electrical environments. You should still not run your model lamps when doing this, however.

You could modify and use the cable linked to. However, that site sells custom cables at a reasonable cost. http://www.powerwerx.com/adapter-cables ... -cable.asp

Thank you for your clear and direct answers. I don't think those little UPS batteries can provide 30A continuous for very long if at all, and a big SLA is a non-starter. Therefore, it seems, the PCB battery wins. In the grand scheme of things, considering how much photographers spend on equipment and accessories, the $90 or so for a long-lasting high quality battery is negligible. But it's good to know how easily such a solution can be cobbled together. I'll try to remember to make a cable and bring it along whenever I have the VML just in case the MacGyver opportunity arises for me to power a flash with a car battery and a homemade cable. :lol:

Thanks for clarifying the charging while shooting question. I'm pleasantly surprised to learn about this very useful feature!