Kyle, just tested it with an M1000DR, recycle to full power took 5.5 seconds. You won't get many pops at that rate, but it's a good worst case scenario test as far as amp draw. I'd offer to hook up 2 1k's but I think I'm already pushing my luck, so I'll let someone else who does this build :-)
bacilonur wrote:
Kyle, just tested it with an M1000DR, recycle to full power took 5.5 seconds. You won't get many pops at that rate, but it's a good worst case scenario test as far as amp draw. I'd offer to hook up 2 1k's but I think I'm already pushing my luck, so I'll let someone else who does this build :-)
Thanks for the info! That's a pretty long recycle time, but for such a tiny pack I'm not surprised. Could make a good backup though...
I'd like to build myself one of those but with double the capacity. I'm having trouble finding a 60Ah LiFePO4 battery with 400A max current capability!
foto-z wrote:
I'd like to build myself one of those but with double the capacity. I'm having trouble finding a 60Ah LiFePO4 battery with 400A max current capability!
I don't think that exist anyway. I have yet to come across any LiFePO4 cell when has over 5C continuous discharge rate. You can however, build a pack with cells (http://tinyurl.com/yz9ykw3) in parallel connection:
The Samlex inverters today can take Li-Ion cells as well(12V inverter's max input voltage is 16V and @24V is 33V. I am wondering why would you need 400A? 24V 1000W inverter max. draw is about 80A (both the fuses on 12V and 24V 1000W inverter are 5x15A according to Samlex's site, could be a typo, I think 12V should be 5x30A). If you need more power, perhaps building another individual pack is a better idea due to limitation of wires.
400d wrote:
I am wondering why would you need 400A?
I am planning to use a 5kW inverter, 12V.
I was hoping to be able to use a battery lighter than the lead acid ones I use in my current 1.5kW setup, but for heavy duty applications they still seem to be the only practical option.
Assuming the cells are from the same batch, I doubt it would be a significant problem, except the QC of the battery is really poor. The example shown under 12.2 is hard to achieve in the first place, 13.2V and 10.5V, that must be one really bad cell for its voltage to drop that quick under any load. From my experience, LiFePO4's voltage is very stable under load, usually around 3.2-3.3V.
There is no single cell (including Li-Ion) on the market which has a capacity of 60Ah and current rating at 400A. Since the 5kW inverter is already 30lb, there won't be much difference if you use 200Ah cells. If you can use 24V or 48V inverter instead, you will need only 1/2 or 1/4 amps of draw @ 12V.
Have you done any field testing with this remote power source?
Given the size and ability to deliver reasonable recycle for an AB800 it would be perfect for a mobile rig.
Would like to hear your impressions after using it in the field.
Just one random thought here. I used to race RC cars. We went through a TON of batteries, when ever a new higher capacity cells came out the old ones were 'no good' cause they were non-competitive. Plus they were top condition for a season or so, and would get relegated to practice use only. Why am I talking about this? If you can find a RC racer, you can find a source of 'bad' batteries that you could probably pick up at a nice discount. They have plenty of usable life left for this type use, you might loose 10 full power shots by using 'used' batteries. Big thing with NimH or Lipos is to keep them charged, and don't leave them in the closet for a few months.
Hey David, I used it for about an hour on Saturday and it worked great. I was mostly around 150-220ws and recycling was plenty fast. I just did a max pops test with a B800 and I got 172 pops. That was during just 15 minutes, so you'll probably get at least 10% more in the real world when you're not shooting that fast and making the inverter work so hard--I know I tend to shoot around 100 frames/hour.
Recycle started at around 2.5 and ended at 2.7s right before it died, which is pretty good. The next test I do will be with a few monos plugged in at full and minimum power. With a replacement battery just $60 and 1.5lbs, it's a good idea to keep on on hand. I'm going to use velcro to strap the pack inside the case, so swapping ou the battery should take about 10 seconds.
Huff, that's definitely a good idea if all you want is a random pack to throw in a soft case or if you're looking to make your Vagabond lighter, but I'd rather pay the $60 so that I can get the most power per square inch.
That pack is very interesting. I only have Alien Bees B1600s. Would it work on those? I presume it would take five to six seconds to recycle to full power. I like the idea of it being small - perhaps just for when I need to run a single light on batteries at lower power for a few flashes. (I shoot interiors so I might have a battery unit hidden where it is hard to run AC.) But I also might want another unit with faster recycling and more capacity.
Would I get better performance (faster recycling) going to a heavier 300W unit? Are there similar larger cells for higher capacity batteries? (Although several small packs could be ok.)
A B1600 recycles in about 4.8 seconds. With the PLMs and HOBD and the new 11'' reflector, 640ws isn't as necessary IMO. A pack this small works better with a B800, but you can easily make one a little bigger for the B1600. My third pack is a Pelican 1120 with a 9 12Ah D cell pack, yielding about 55% of the VB2's battery capacity. Two packs, two ABs, two Nano stands, and all the cables and triggers you need fit right in a 1510 w/ dividers. :-)
A B1600 recycles in about 4.8 seconds. With the PLMs and HOBD and the new 11'' reflector, 640ws isn't as necessary IMO. A pack this small works better with a B800, but you can easily make one a little bigger for the B1600. My third pack is a Pelican 1120 with a 9 12Ah D cell pack, yielding about 55% of the VB2's battery capacity. Two packs, two ABs, two Nano stands, and all the cables and triggers you need fit right in a 1510 w/ dividers. :-)
Thanks, I do need high power fairly often and I have several large Balcar battery systems for that. The advantage of the small battery pack is that it works on the ABs, is inexpensive, and I can have it available for occasional use - often way lower than full power. Such as inside a shower or as an accent light.
I never figured that a 180W inverter would be strong enough. But if you say so, I may build one. Again, you don't see much advantage in going with a 300W inverter considering the added weight?
You can use a 300W instead, but then your all-up weight will be about 9.5lbs instead of 5.5lbs (using the same battery pack with a 180W inverter and a smaller Pelican). The smallest Pelican you can fit a 300W is the 1200, which is basically the same size as a VB2. Still half the weight, though.
This thread has given me an idea. I have a Norman P808 which is a fairly compact pack system. So, I have been thinking of maybe making one of these units in a flat case that would clamp up to the bottom o the power pack, making it a 800ws battery portable unit. Since the Norman only has a 7amp circuit breaker it ought to work well in such an mode.
Unfortunately, it will be awhile before I have any spare change to do something like this.
bacilonur wrote:
You can use a 300W instead, but then your all-up weight will be about 9.5lbs instead of 5.5lbs (using the same battery pack with a 180W inverter and a smaller Pelican). The smallest Pelican you can fit a 300W is the 1200, which is basically the same size as a VB2. Still half the weight, though.
Thanks,
I'll may build the 180W unit with a small battery pack. I'll probably use a Rubbermaid type container. What stopped me from getting the Vagabond is that I already have a lot of battery gear that is big and heavy. But I might be able to justify a light weight unit.
This is an interesting project and thanks for sharing it. I am a big fan of Eneloop batteries and was wondering how well they might work in this. I believe the D cells are 5Ah. Too much weight?
I have the components ordered to build one of these. They should arrive within a couple of days.
I am wondering were you got the larger capacity D Cell battery. That would be a nice option.
They won't fit the 1050, but that 3x3 configuration fits the 1200 perfectly. Using 9 cells instead of 10 will yield 10.8v instead of 12v, but that fits within the 10-15v power range just fine.
