6500 mAH 12v Li-ion

[Tom Frisch]

Anyone tried these yet?

http://cgi.ebay.com/6500mA-12V-Super-Rechargeabl-Li-ion-Battery-For-Camera_W0QQitemZ200332509858QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item200332509858&_trksid=p3286.c0.m14&_trkparms=66:2|65:15|39:1|240:1318|301:0|293:1|294:50#ht_1304wt_1166

$40USD for a 12v 6500mAH Li-ion battery and AC adaptor (which I assume is a charger)

If you multiply amphours by volts you get 78WH, which is not too shabby for a $40 battery.
Put 2 together and you've got 156WH, which is up near the AB Hyron batteries that cost $530 each.

I'm assuming the AC adaptor charger is a 'dumb' charger that keeps feeding voltage to the batteries even after
they are fully charged- so it would be easy to break them.  Not sure, there are very few details on the ebay page.

-Tom

[danny tuscan]

Geez thats cheap for such a large capacity!!

If only i hadnt ordered the 1800mAh from china that other people on the forum are using. Was ~$30 for two 12v 1800mAh.

Yea, i think they have the circuit that prevents overcharging built into that unit.
But still dirt cheap!

[Tom Frisch]

Took a risk, ordered 2.  Will let you guys know how they work for me.
Anyone know of a simple voltage level circuit?  The kind where you push a button and
little LEDs light up to show how much charge is left?

Also, anyone know of an affordable 12v to 7.2v switching converter that I can use to power
my camera from the same batteries that are running my monitor?

-Tom

[Tom Wills]

Also, anyone know of an affordable 12v to 7.2v switching converter that I can use to power
my camera from the same batteries that are running my monitor?

-Tom

You might want to try something along the lines of this. I used an older version with lower capacity to run my monitors, but ditched it because the capacity wasn't high enough. This one should do fine though, as it supplies up to 3A at any of the voltages that it supports.

http://dimensionengineering.com/DE-SWADJ3.htm

I ended up passing mine on to a friend of mine who builds robotics. It's probably somewhere in some little rover somewhere now.

[danny tuscan]

Hey Tom,
once you get it, do you know how you will be hooking it up and stuff?
What about an enclosure for it?

excited to see the end results!

[Tom Frisch]

Haven't gotten that far- maybe a hammond box, preferably plastic, possibly aluminum.
Thought I'd wire them together to make one massive battery, which should power my monitor all day.
Probably will take all day to charge as well, not sure how that all works.

Yep, flying blind.

-Tom

[danny tuscan]

http://hbsboard.com/index.php/topic,3708.30.html

Hey Tom, while reading that thread, the box that Michael is using is from a store called mouser (half way down).

I think thats a good solution, but kinda expensive at ~$20.

Depending on how the 1800mAh battery is, i might just order the 6500mAh and create a custom box.

[Tom Frisch]

Just received my 2 batteries in the mail from China today.
They are quite small and light, 4" x 2" by a bit more than 1/2" thick.
Together I'd guess they weigh about 1lb.

They have 2 wires coming off them, ending in the usual power supply kinda plug,
one male, one female.

I measured the volts coming out, it shows 12.64v

They also came with an AC adaptor which is for charging.  Haven't tried them with anything yet.

-Tom

[Chris Harding]

Hi Tom

I got 2 of the 1800mah Li-Ion batteries from China last month. I figured that my monitor runs at 800ma for one would last for an hour hopefully and the second one would be a backup.

I did a wedding shoot on Saturday 27th and used the stedicam for the limo arrival. the brides exit and walking down about a million stairs (well it felt like it!!) to the outdoor ceremony. I then did a full hour plus photoshoot with the photographer and the monitor was STILL happy as ever after all that without needing to change to the second battery!!! With your 6500mah ones I figure that you could happily shoot all day!!

The 1800mah ones cost me $19 each including shipping!! and to me they were certaining worth it!!!  I previously was using a 12v 1.2ah gel battery which would normally die halfway thru the photoshoot and weighed about 5 times as much!!!   They are actually excellent value but I suspect they are just a bank of 10 x 1.2 cells connected together and put in a box but the price is good, the on/off switch is useful and they work pretty well too!!!   I can definately also see a use for these lightweight ones on a LED light panel mounted on camera!! (I currently use 2 x 7.2v camcorder batteries!!)

Tell us if you have the same favourable results???

Chris

[Carter Raff]

Tom, can you tell me the seller on ebay where you got these batteries, those are a hell of a good price.

[Vladimir Korshunov]

http://shop.ebay.com.au/i.html?_kw=cctv&_kw=li&_kw=ion&_ckw=v

 

[Tom Frisch]

Now it looks like they are up to 9800mah!

http://cgi.ebay.com/CCTV-DC12V-Super-Rechargeable-Li-ion-Battery-9800mah_W0QQitemZ230362408370QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a2ab65b2

[Carter Raff]

How is that possible??? If you look for a 6500mAh on a discount R/C Site they are like $300!! That is a hell of a price, I'm sure it's not the highest quality but that's a long lasting battery.