Topic: External power for SD 7xx

[johnw]

Looks like I'm going to Langerado and will need external power. I have one of the Sony battery widgets like in the picture below but have a couple of questions.

1) What batteries are people using to power these?
2) Can the batteries from the first question go with me on the plane?
3) Looking at the cable on the Sony widget which is the +/- wires or to make it easier on me, which wire to I connect the red to and which do I connect the black to? One wire has writing and the other has a white line. Or does it not matter?

[stevetoney]

Looks like I'm going to Langerado and will need external power. I have one of the Sony battery widgets like in the picture below but have a couple of questions.

1) What batteries are people using to power these?

I copied only the first question since that's the only one I can answer.  Bean, bless his heart, made me up a really cool cable which uses this same dummy cell that you're showing in the picture for running external power for my 702.  From the dummy cell, it splits off to three of the Tamiya connectors where I'll have three 7.2V RC batteries.  I haven't bought the batteries yet, but if I buy six 3800mAH RC batteries, that should give me a good 10 - 12 hours run time for each batch of three.  That means I should have a full days worth of power with each set of batteries and can be recharging the second pack on the off day.  Course that's running the 702 with phantom...if I run my new m148 I won't be using the 702's phantom power so it might just run into next week with these RC batteries.

I'm also flying to Florida for Langerado.  So, I'm also curious about what will be allowed on the flight.  However, I'm gonna be visiting family earlier in the week, so I may have to mail the batteries down ahead of time and then have them mailed back afterwards...which would be a royal PITA, but maybe the only alternative. 

That's a good REALLY question to investigate ahead of time though.  It would totally blow if  you get to the airport and find out that they won't allow your batteries, in which case the only alternatives on the spot might be to either miss the flight or throw the batteries in the trash.

[johnw]

Could you post a picture of the wires going into the dummy cell? That would at least let me know how to wire the thing.

John

[manitouman]

I just got one of these bad boys...10,000 mAh's!

http://www.onlybatterypacks.com/showitem.asp?ItemID=10953.8

[stevetoney]

Could you post a picture of the wires going into the dummy cell? That would at least let me know how to wire the thing.

John

OK, no problem, but I have to leave in about 15 mins for several days on a biz trip and won't be back until Thursday.  I'll post some pics then.  I'll PM you then to see if you haven't found a solution yet.

Steve

[thegreatgumbino]

Looks like I'm going to Langerado and will need external power. I have one of the Sony battery widgets like in the picture below but have a couple of questions.

1) What batteries are people using to power these?
2) Can the batteries from the first question go with me on the plane?
3) Looking at the cable on the Sony widget which is the +/- wires or to make it easier on me, which wire to I connect the red to and which do I connect the black to? One wire has writing and the other has a white line. Or does it not matter?

Question #1:

Lots of info in the following threads:

http://taperssection.com/index.php/topic,76738.0/all.html
http://taperssection.com/index.php/topic,53294.0/all.html
http://taperssection.com/index.php/topic,68176.0.html
http://taperssection.com/index.php/topic,66159.0/all.html

Question #2:

http://taperssection.com/index.php/topic,36124.0.html
http://taperssection.com/index.php/topic,96259.0.html

Question #2:

On the left side of the battery in the picture you attached you can see the dummy sled has a "+" and "-" on the respective sides.   The other side of your cable will be wired according to the pin out of your battery/setup.

[johnw]

I saw that and I'm wondering if the wires correspond. In the picture the + is on the bottom as is the wire with the white stripe. The - is on the top as is the wire with the writing. So is the white striped wire the +? I just want to make sure the wires don't cross inside the dummy cell and I get it hooked up and fry my 702. Thanks!

[johnw]

I just got one of these bad boys...10,000 mAh's!

http://www.onlybatterypacks.com/showitem.asp?ItemID=10953.8

Have you tested how long it will run a 7xx? I'm assuming 9-10 hours with phantom on. How long does it take to charge and what charger are you using?

[johnw]

Is it possible to make a sled out of AA batteries to run this thing? In the thread where moke ripped apart a Sony bat to make a dummy cell, there were 4 LiIOn AAs in there. Since high capacity batteries can be found at many local retailers, maybe this would be a solution. That way I could just stock up when the plane lands.

[thegreatgumbino]

I saw that and I'm wondering if the wires correspond. In the picture the + is on the bottom as is the wire with the white stripe. The - is on the top as is the wire with the writing. So is the white striped wire the +? I just want to make sure the wires don't cross inside the dummy cell and I get it hooked up and fry my 702. Thanks!

If you have a continuity meter put one end in the "+" socket and the other end at the end of the corresponding wire.  Repeat for the "-".  If you don't have a continuity meter, stop & don't pass go until you run to Radio Shack and pick one up.

[manitouman]

I have not tested or charged it for that matter. I'm waiting for a cable to be prettied up for me and then sent back. Then I will charge and test a few times just to see what I get. I'm also assuming ~10 hours. Battery $75 shipped w/Tamiya connector. And bought the charger here:

http://cgi.ebay.com/1-Universal-Smart-Charger-RC-7-2-12V-NiMH-RC-Battery_W0QQitemZ270205452836QQihZ017QQcategoryZ48618QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Cheapest I could find anyways. I've looked at the combos that are offered on some places but I figured I'd only have to carry one battery pack @~10hours instead of two battery packs @~4-5hours. The batteries in the pack are Tenergy brand, if that matters any?

Good luck with your project!

EDIT: I think, and I stress the "I think" part, the wire with the stripe is negative. But don't take my word for it!

[johnw]

I have not tested or charged it for that matter. I'm waiting for a cable to be prettied up for me and then sent back. Then I will charge and test a few times just to see what I get. I'm also assuming ~10 hours. Battery $75 shipped w/Tamiya connector. And bought the charger here:

http://cgi.ebay.com/1-Universal-Smart-Charger-RC-7-2-12V-NiMH-RC-Battery_W0QQitemZ270205452836QQihZ017QQcategoryZ48618QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Cheapest I could find anyways. I've looked at the combos that are offered on some places but I figured I'd only have to carry one battery pack @~10hours instead of two battery packs @~4-5hours. The batteries in the pack are Tenergy brand, if that matters any?

Good luck with your project!

EDIT: I think, and I stress the "I think" part, the wire with the stripe is negative. But don't take my word for it!

Thanks! I think the wire with the strip is negative as well, but I'll test it with a continuity meter as greatgumbo suggested.

[fozzy]

please do not pass go w/o testing w/ a multimeter.  If i remember correctly the wire is tied in a knot as a privative(yet common) strain relief.   There may also be a capacitor in there too, i removed it.

[guysonic]

I just got one of these bad boys...10,000 mAh's!

http://www.onlybatterypacks.com/showitem.asp?ItemID=10953.8

Very nice 70 watt bundle of power.   If deck draws 7 watts, then this pack good for ~10 hours running time.



Designed a real 'bad boy' 12 D cell power sled for SD decks that's surprising light weight. 

Filled with regular heavy duty Alkaline D cell, and you've got a 250 watt super capacity pack, but weighing all of 4 pounds and running same 7 watt deck for 35+ hours!  Great for rural festivals and remote expeditions where heavy batteries, recharging/swapping batteries is best avoided with highly reliable alkaline.   Renewal time: 2-3 minutes to install fresh cells.

If instead wanting a rechargeable pack, then loading 12 same NiMH D cell as in 70 watt pack gives lower capacity 150 watts, heavier weight than alkaline 250 watts, and with 7 watt deck, running time expected is ~20 hours, with recharge time likely 6-24 hours. 

Cost of extra capacity D cell NiMH is not cheap to buy, and then there's need of charger(s).  But investment is good value if recording urban locations with frequent overnight for recharging gear, and over many years time rechargeable pack is likely renewable/reliable enough to last the life of the deck, but mostly true only with careful charging/storage management practices.

BD-12T is similar to BD-8 construction, but with power plug for SD decks, and 1-cell position longer holding 4 more cells than BD-8

BD-12T specifics at: www.sonicstudios.com/batsys98.htm#bd12

I know many here also are DIY, and can wire your own battery sleds together so take a look a photo of BD-8 for unique construction details

Notice the internal thermal safety fuse that's very important to avoid smoke/melting stuff if something gets shorted.

Notice white self-supporting molded plastic battery sled that is very rigid so cells, even heavy NiMH, don't move to momentarily disconnect to cause recording faults with battery sled flexing.

These white self-supporting battery sleds are no longer available from large north American/European parts distributors (maybe surplus/special order), only non-self supporting black poly plastic types are now stocked. And these mostly needing to be attached to something rigid to keep cells from moving around.  So if wanting to make your own, attach sled to stiff metal plate or some other rigid surface.

[fozzy]

i just don't like that NiMH weighs twice as much as li-ion packs.

you can get 10amps of li-ion for less than a pound