If you don't feel confident soldering batteries together, many of the local
battery supply places
will rebuild battery packs. Often they will do the joining together for free
if you buy
the batteries from them.
I've done it a couple of times with old nite rider packs. The first one I soldered myself using low temp solder, but then broke one connection on a bumpy ride, had to redo it. I've had better luck with the tabs already installed, then solder to those. The mAh is milliampere-hour rating of the cell. 3800 would be equal to 3.8 Ah. One of my packs also had a small diode or resister in it that prevented overcharging. If you have something like that make sure you get it back in correctly. Good luck.
Dave
----- Original Message -----
From: Jason Crago
To: Obra
Sent: Thu, 3 Jun 2010 17:44:06 +0000 (UTC)
Subject: [OBRA Chat] Battery Questions
Anybody out there have experience building their own battery for a light
system.
I have a Light and Motion 10.8v, 3.8Ah battery that died a couple of
years ago. Because of pricing I replaced the whole system but now the
second battery is starting to have shorter burn times. I still have the
second HID head that I haven't used. I took apart the original battery
and it is a series of 9 4/3AF cells, it looks like it would be really
easy to order some cells online (anywhere from 3 to 6 buck a cell) and
put it together. That being said I've never done that and am looking
for advice
What does the mAh stand for, some cells are 3800 and others are 4200.
Will that change the size?
Online it looks like if I want to do my own soldering I need to order
them with 'tabs', what are they.
Anything special I should know about soldering the cells together?
Thanks
Jason
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Easy enough job if you're handy with a soldering iron and basic tools.
mAh stands for milli Amp hours and is a rating of electrical storage
capacity. 3800mAh indicates that the cell will provide 3800 milli Amps
of current for a period of one hour. Higher numbers therefore are
better. This has no relation to the physical size if the package ("AA",
etc.) is the same.
Yes, the tabbed option is best for building a battery as you cannot
solder them together without damaging the cell otherwise.
Avoid excessive heat by using a high temperature soldering iron (it
heats locally quick and minimizes "heat soaking" into the package).
Be sure you pay attention to the final voltage of the battery. Different
cell chemistries (Ni-cad, Li-ion, etc.) have different voltages so if
you change the cell type the number of cells may need to be adjusted. It
is important that the voltage is in the proper range both for the light
system and the charger.
Not all chargers are created equally, so called "smart chargers" are
well worth the investment because they increase the cell life. Different
cell chemistries have different optimum charge profiles. Be sure your
charger is designed for the cell type to get maximum life out of the cell.
Rick Johnson
Bend, Oregon
Every revolutionary idea seems to evoke three stages of reaction...
One, it's completely impossible.
Two, it's possible, but it's not worth doing.
Three, I said it was a good idea all along.
Arthur C. Clarke
Jason Crago wrote:
> Anybody out there have experience building their own battery for a
> light system.
> I have a Light and Motion 10.8v, 3.8Ah battery that died a couple of
> years ago. Because of pricing I replaced the whole system but now the
> second battery is starting to have shorter burn times. I still have
> the second HID head that I haven't used. I took apart the original
> battery and it is a series of 9 4/3AF cells, it looks like it would be
> really easy to order some cells online (anywhere from 3 to 6 buck a
> cell) and put it together. That being said I've never done that and
> am looking for advice
> What does the mAh stand for, some cells are 3800 and others are 4200.
> Will that change the size?
> Online it looks like if I want to do my own soldering I need to order
> them with 'tabs', what are they.
> Anything special I should know about soldering the cells together?
> Thanks
> Jason
> _______________________________________________
> OBRA mailing list
> obra@list.obra.org
> http://list.obra.org/mailman/listinfo/obra
> Unsubscribe: obra-unsubscribe@list.obra.org
>
Anybody out there have experience building their own battery for a light
system.
I have a Light and Motion 10.8v, 3.8Ah battery that died a couple of
years ago. Because of pricing I replaced the whole system but now the
second battery is starting to have shorter burn times. I still have the
second HID head that I haven't used. I took apart the original battery
and it is a series of 9 4/3AF cells, it looks like it would be really
easy to order some cells online (anywhere from 3 to 6 buck a cell) and
put it together. That being said I've never done that and am looking
for advice
What does the mAh stand for, some cells are 3800 and others are 4200.
Will that change the size?
Online it looks like if I want to do my own soldering I need to order
them with 'tabs', what are they.
Anything special I should know about soldering the cells together?
Thanks
Jason
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