quick advice needed: battery for Manhattan monitor
 

I have the Manhattan LCD monitor on order; the manufacturer says it's good for 9-13V; my PAG battery is rated 13.2V - will it be save to power the monitor from it?

li-ion batteries have to kind of label.
the one that gave the nominal voltage and the one that gave the highest (charging) voltage. Both are used for same batteries, so you can find a 7.2V labelled 8.4, but it is the same battery.

the usual range is a multiple of the 3.6 single cell.
so you get 3.6 - 7.2 - 10.8 - 14.4 etc.....
or you can get more rarely a 3.7 reference so it gives different numbers
so you get 3.7 - 7.4 - 11.1 - 14.8 etc....
if they use the charging voltage , it is 4.2V per cell.
so you get 4.2 - 8.4 - 12.6 - 16.8 etc...

to say that a fresh charged 4 cell li-ion battery can peak at around 16V.
to keep in the safe range you should use only a 3 cell battery that could have 12.6 at highest and 10.8 at lowest, so you are always safe.

you can build or buy such battery at Rechargeable Battery Pack Li-ion NIMH NICd Li-Po Battery Charger for any capacity you want.
usually common li-ion cell is around 1800 mA (1.8 Amps) per cell.
it already a lot for small lcd screen that needs usually less than 1000 mA.

13.2V indicate a ni-mh technology. it is not as powerful as li-ion but cost less.
the voltage scheme is slightly different since nimh single cell is 1.2V, so you get more
latitude to build pack with voltage aligned with your need.
13.2V would means a 11 elements cell rated 1.2V, or a 10 (likely) elements cell rated 1.32V.
again one numer is the nominal use (1.2) and the other is the charging voltage (1.32).

I think there is no problem to get 0.2V over the range specified on the screen.
if you want to be on the safe side, you can put a diode in the circuit. Common diode will cause a drop of about .7V so you will never be higher than 13V.
you can use a common rectifier diode supporting the current needed for the screen (or put several diodes in parallel if needed).

Thanks, Giroud.

Giroud,
I just examined my PAG battery; it seems there are 6 cells in it - it wouldn't fit any of your descriptions. What voltage do you suppose they are (13.2 : 6 = 2.2)?

I'm trying to figure out the "worst case scenario", where - when fully charged (or even overcharged), any battery can produce a voltage much higher than the nominal value (which in my case, is just at the acceptable voltage range boundary). How much more do you think it could be right after full charging?

The ManhattanLcd customer support seems quite helpul, but very terse in their answers; that's what they answered to my dilemma:

"13v is ok, 14v not ok".

The Tekkeon MP3450 seems to be popular for powering those LCDs.

Tekkeon - myPower ALL, MP3300/MP3400/MP3450

Tekkeon myPower All Plus, #MP3450 - eXpansys Poland

John

Piotr,

I use Tekkeon 3450 for my ManhattanLCD monitor.

It's juice is enough for almost 3hrs straight, in my experience.

BTW, what are your color mode/brightness/contrast settings with Manhattan LCD? Out of the box, it has a lot of blue tint.

Alex,

Thanks for the advice; John of ManhattanLcd has sourced the 3450 for me.

As to the settings - cannot say anything yet; I'll only be getting mine next week!

You're welcome... make sure to get some strong Velcro or 3M to attach the battery to the back of the monitor (that's what I do, makes for a compact unit...)

Also may I recommend the component cable extender. Very useful when you need to set the lights etc. - allows you to position the monitor where you are, not where the camera is.

http://www.svideo.com/co6.html

I got me a 6ft one, and it works great. In retrospect, given how slim it turned out to be, I'd get a 12ft one instead...

Piotr,

you always find cool gadgets :) I better watch your moves.

Could you please post a photo of this Manhattan LCD once arrives, mounted with your rig - so i can assess how big it is? I might consider buying one if not too large - its price is definitely tempting. Please post your experience with its picture quality, too.

Thanks a bunch in advance,

Zsolt

Will do, Zsolt - I promise!

Btw, have you ordered it from the website or you have a distributor in Poland? (no need to post link :)

possibly you got Li-ion pack with 2x3 cells rated at maximum charging voltage (4.4)

Straight from their website - the guy named John (very helpful) has also sourced for me some additional stuff - apart from the battery and the Manfrotto Apron (a smart "bag" to mount between your tripod legs, where you can hold things like batteries etc.), all the parts for mounting the monitor to the tripod leg.

Yes, John is very helpful and a cool guy.

What did you get to mount the monitor to tripod's leg - this ?

Yes, Alex.