NewStuff
13 years ago
"Roy Morton" wrote:

"Mr Mike wrote:

Most powerful are the Bridgelux LEDs, 8000lm @ 100lm/w and can be driven to 12000lm, voltage for portable apps is a bitch though at 36V



3 car batteries and a sack trolley? :lol:



A sack full of Li-ions is still something I'm debating since Mr Mike linked me to these a while back. If I could figure out how to balance the cells without buying a charger that would cost as much as a decent lamp, I'd do it, I have plenty of Li-Ion cells and heatsinks kicking around.
Searching for the ever elusive Underground Titty Bar.

DDDWH CC
Mr Mike
13 years ago
This will do nicely:

http://www.batteryspace.com/customizepolymerli-ionbattery37v4ah148wh15adrainratepl-6050140-10c.aspx 

and at only 850g, lets dump the SLA!

Built in balancer,

And for the charger:

http://www.batteryspace.com/smartcharger30afor37vli-ionpolymerrechargeablebatterypack.aspx 

Jobs a goodon, but expensive one. Dream.
Mr Mike www.mineexplorer.org.uk
royfellows
13 years ago
The HK suppliers do cheap balance chargers for model planes etc. I use the PCBs and only had one bad one out of loads and loads.

Main issue at the moment is duff LiIon cells, once one becomes part of an array and potted into an outer case, well you can see where I am goint to on this.
My avatar is a poor likeness.
NewStuff
13 years ago
My charger will balance up to 6 cells. I'd need double that for this.

However, Mr Mike seems to have the solution. Looks like an e-bike battery. Someone with deeper pockets than me should have a little experiment with it.
Searching for the ever elusive Underground Titty Bar.

DDDWH CC
Mr Mike
13 years ago
You can actually buy the balancing PCB:

http://www.batteryspace.com/pcmwithequilibriumfunctionfor37vli-ionbatterypackat15alimit.aspx 

Maybe with a little looking you could buy something similar from another source?

And a cheaper of the shelf solution would be to buy 2 x 18.5V packs and use them in series, with two chargers.
Mr Mike www.mineexplorer.org.uk
NewStuff
13 years ago
This looks promising too - I've only had a quick Google about.

http://www.batteryspace.com/pcbforli-ion18650batterypack-36v37v27a-1alimit.aspx 

If I didn't have so many projects on at the moment, I'd go for that.

If no-one else has taken it on when I have some free time/money, I'll do it. I have 18650's coming out of my ears, it shouldn't be a problem to match 10 up and charge them to slightly above nominal.

I seem to remember seeing drivers for Overhead lights that could deal with the regulation side of things.
Searching for the ever elusive Underground Titty Bar.

DDDWH CC
exspelio
13 years ago
The articles on this thread keep reminding me of my old mate Buster (RIP), back in the late '70's, early '80's, he was into super 8 cine in a big way, he invented caving filming lights; two car headlights mounted on a back pack carrying frame so they shone over his shoulders, and a car battery, later replaced by half a dozen Oldham cells wired in series fastened to the frame between. He managed some impressive results with this system and even showed his films at Hidden Earth.
I wonder where his films ended up.

Another memory was carrying Sid Perou's codged up and abandoned battery packs from the far reaches of Otter Hole, they were NiFe cells cobbled together in quarter inch plywood boxes, not condusive to a prolonged spell underground! They ended up strapped together with bandages from the first aid kit and left at the inward side of the tidal sump!

Ahh, happy days ๐Ÿ™‚ ๐Ÿ™‚
Always remember, nature is in charge, get it wrong and it is you who suffers!.
Roy Morton
13 years ago
Whilst rooting about in the workshop the other day looking for something completely different, I came across this contraption I cobbled together years ago.
It consists of 3 LED's, nowt special, and a load resistor crammed into an old Oldham pilot lamp base, and held together with hot-melt glue.
It cost less than a quid, worked a treat and still does, but has now been relegated to the 'museum' under the bench :lol:

๐Ÿ”—Personal-Album-342-Image-79204[linkphoto]Personal-Album-342-Image-79204[/linkphoto][/link]


"You Chinese think of everything!"
"But I''m not Chinese!"
"Then you must have forgotten something!"
ChrisJC
13 years ago
I still use something very similar (1 LED) in my FX Headlite as the pilot bulb. Cost me nowt as somebody gave me the LED.

Chris.

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