Help with a new HID Blitz battery pack.

Sway

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Aug 25, 2003
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Hi Gang,

I need a new battery pack for the 35/50 HID Blitz, it has grown a little short winded here lately. I'm not sure if one of the cells has gone bad or if all of them are just showing their age from the current draw at start-up and the 50W runs.

The current pack is made up of 12 4000mAh 4/3A cells, I'm not sure what the start up surge is (10A+?) but it draws 3.63 amps at 35W and 5.13 amps at 50W, this may have been a little much for these cells from the start looking back, I'm not sure.

I'm open for suggestions as what to use in the new pack, NiMH is still the most economical choice but what cells will handle the current draw, have around a 4000 mAh capacity and still be small enough to fit in a camera pouch. 12 C cells end up being a little larger than I want to use.

Li-Ion, looks like it would take several sets of series/parallel packs to handle the start up surge what ever that is and the 50W setting. Would I have to charge the packs separately or could they be charged as one?

Li-Poly, something I'm not thrilled about because of the cost, handling concerns still worry me and the same charging question arises.

Any suggestions or input would be greatly appreciated.

Later
Kelly
 
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Tweek

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May 12, 2003
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Groton, CT
The 2500 Energizer / Sanyo AA's will take that kind of load without breaking a sweat, perhaps a series-parallel arrangement to increase the pack capacity? Could even go with single strings of 12 cells, just swap one for another when they run out, should be good for 20 minutes minimum at 50W. Would definately fit in a camera pouch too... :)

Chris
 

markdi

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Jun 27, 2003
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Portland Oregon
I am using 12 4.5ah nimh c cells in my 35 watt hid vector mod(greenbatery cells)

I have only charged the vector at 1/10c and I have charged the pack about ten times or so

I get 85/90 minutes runtime per charge.

what do you get for runtime usung 4/3 aa's ?

how much lighter are the 4/3 aa's as compared to c cells ?

I have read that hid bulbs color shifts after about 100 hours or so.
so if you start with a 4300k bulb it shifts to about 4700k.

I am thinking about running my hid lights from a power supply
to break in the bulbs - raise the color temp.

should I disconnect the nimh battery ? - will float charging it for 4 - 25 hour runs damage my nimh pack in my vector ?

sorry but I had to ask.
 

Sway

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Location
North Carolina
Tweek
I have some of the 2500 Sanyos and they are very nice cells my favs but the current requirements are a little much for them from looking at Tom's graphs, do wish they would work though.

Mark
The 4/3A's weight 55 grams each and from what I can find on line the weight for a comparable C cell is roughly 20 grams more or around 1/2 pound for the pack of 12. The A cells played into the goal of keeping the weight down when I made the light the whole package came in under 6 pounds :)

Eh's guess I'm going to look into some Li-Ion's :broke:

Later
Kelly
 
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Tweek

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Groton, CT
Li-ion's can work nicely, but they get expensive fast! I used 21 (7S3P) of the LG 2400's (18650's) in my Husky spotlight mod to keep the current draw in the reasonable area for the cells. I have yet to actually run them down much further than halfway, and they're holding up fine, I'm pulling almost 2C out of them when they're fully charged.

I did a little torture-testing on them when I first got them:

18650_2400mAh.jpg


8 of these cells in a 4S2P setup would work nicely for your application, they would give a good 45 minutes of runtime on 50W output, and over an hour on 35W. They'd be a small package, and not very heavy either.

Chris
 

Sway

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Location
North Carolina
Tweek,

Thank you very much for the plot!

Guess I will give the Ion's a spin this time you just have to love the low self discharge and the energy density. I think I can get by with two series packs of 4 cells in parallel this will give me 14.8v nominal with 4400mAh capacity, I can always add another pack if needed.

The battery weight for the Ion's works out to around 13oz vs 23oz for the NiMh cells SWEET! :sold:

Later
Kelly
 

modamag

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Aug 16, 2004
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Bay Area, CA
Kelly,

Li-Po is not hat bad. The $$$/mAh will be almost identical to the Li-Ion. Some of the packs allow you to charge in series and they have extra leads to allow you to charge individually.


The problem is form factor. Let me know your dimension and I'll see if what I got will fit for ya.

Jonathan
 
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