Some thoughts on Vistalight (vistalite?) batteries

Have you ever seen the discharge graph for NiCd batteries?

It goes roughly:

|...............
V | :
| :
+====================
time

I can tell you that NiMH feels about the same.

The problem is that, as Murphy would have it, that
abrupt turn in the graph corresponds to the curve
you're riding down, in the rain, on the commute
home from work. You've just about got time to to
think "Hmmm, that light is looking a bit dull", and
then a minute later it's just about out. Maybe it
had been a bit duller earlier, but riding in those
dawn/dusk times it's impossible to tell.

This has led me to thoughts of other batteries. IMHO the
vistalight 'nitestick' is not too bad, and I think
for it's price it's good, I'm happy with mine anyway.
I must remember to charge it every couple of days though.

But each battery is only 2200mAh at 7.2V. Why is it
such a bulky battery supplies only 2200mAh? I must be
missing something. I know a photo shop that sells 2000mAh
'AA' batteries - admittedly AA is only 1.5 volts (which is
really 1.2V talking NiCd/NiMH).
Wouldn't 6 of these ganged together give me 12000mAh and
probably weigh the same as a nightstick?
Have I missed someting here?
Can someone suggest a better SLA alternative?

A nightstick battery (NiMH) costs about $70,
a pack of 4 2000mAh AAs (IIRC) about $50 with a charger.

cheers,
-kt

yes you are missing something
6 2000mAh AA batteries
can give you
12000mAh at 1.2V or
6000mAh at 2.4V or
4000 mAh at 3.6V or
2000 mAh at 7.2V
maybe it would help if you work it out in w/h
12000mAh at 1.2V or =14.4w/h(l think l have this right)
6000mAh at 2.4V or =14.4w/h
4000 mAh at 3.6V or =14.4w/h
2000 mAh at 7.2V =14.4w/h

yes you are missing something
6 2000mAh AA batteries
can give you
12000mAh at 1.2V or
6000mAh at 2.4V or
4000 mAh at 3.6V or
2000 mAh at 7.2V
maybe it would help if you work it out in w/h
12000mAh at 1.2V or =14.4w/h(l think l have this right)
6000mAh at 2.4V or =14.4w/h
4000 mAh at 3.6V or =14.4w/h
2000 mAh at 7.2V =14.4w/h

On Fri, 04 Jul 2003 23:11:43 +1000, stu wrote:

6 2000mAh AA batteries
can give you
12000mAh at 1.2V or
...
2000 mAh at 7.2V

Ahhh, of course... damn laws of physics.
So I'd be wantin' 8 of "7000mAh size 'F' 1.8v"[1]
to give me 14000 mAh @ 7.2V.
And maybe a trailer to carry them, how big is 'F' anyway.

[1] http://www.onlybatteries.com/showite...temID=10661.25

-kt

On Fri, 04 Jul 2003 23:11:43 +1000, stu wrote:

6 2000mAh AA batteries
can give you
12000mAh at 1.2V or
...
2000 mAh at 7.2V

Ahhh, of course... damn laws of physics.
So I'd be wantin' 8 of "7000mAh size 'F' 1.8v"[1]
to give me 14000 mAh @ 7.2V.
And maybe a trailer to carry them, how big is 'F' anyway.

[1] http://www.onlybatteries.com/showite...temID=10661.25

-kt

l wonder if 1.8V is a typo on there part. l thought all ni-cd batteries were
1.2V and that was it.
l just finished building lights for my bike, you know the ones, 2*20W quartz
halogen down lights
plus a 12V SLA battery.
l used a 7.0 amp hour battery(it does weigh 2.5 kgs so it isn't for weight
weenies)
http://www.customer-self-service.com...popup=1&Produc
t=03294155
when for my first long night ride last night and it seems to be good for 3
hours or more with one light on.
cost me less then $50 including the rear light, but l had all the wire and
stuff. best $50 l ever spent!!!!!!!
great fun

l wonder if 1.8V is a typo on there part. l thought all ni-cd batteries were
1.2V and that was it.
l just finished building lights for my bike, you know the ones, 2*20W quartz
halogen down lights
plus a 12V SLA battery.
l used a 7.0 amp hour battery(it does weigh 2.5 kgs so it isn't for weight
weenies)
http://www.customer-self-service.com...popup=1&Produc
t=03294155
when for my first long night ride last night and it seems to be good for 3
hours or more with one light on.
cost me less then $50 including the rear light, but l had all the wire and
stuff. best $50 l ever spent!!!!!!!
great fun

"stu" wrote in message
...
l wonder if 1.8V is a typo on there part. l thought all ni-cd batteries
were
1.2V and that was it.
l just finished building lights for my bike, you know the ones, 2*20W
quartz
halogen down lights
plus a 12V SLA battery.
l used a 7.0 amp hour battery(it does weigh 2.5 kgs so it isn't for weight
weenies)

Good to see that someone else has decided to build their own lights.......I
still reckon they are the best value for money. I have recently finished my
fifth set of lights for which i machined up an aluminium housing for a 35mm
halogen globe (20W). I made up a NiMh battery pack in an old water bottle
using 10 x 4500mAh batteries which are 4/3 AA size (basically a bit longer
and bit fatter than standard AA batteries). These are in series which gives
me a 12V, 4.5Ah battery.

I am also currently repacking a Vistalight nightstick for a mate whos old
one was pretty well had it. I am using 5 x sub-C NiMh cells (as per the
original) but I have bought 2700 mAh ones from Jaycar (www.jaycar.com.au)
that cost around $9 each. This means my mate gets a new nighstick for
around $45 bucks that has around 25% higher capacity than the original!!!!!
It is a pretty simple process that only involves some basic soldering.

If you are interested in having a look at my lights, they are at
http://members.ozemail.com.au/~drgagnon/lights_5.htm

Cheers,

Gags

"stu" wrote in message
...
l wonder if 1.8V is a typo on there part. l thought all ni-cd batteries
were
1.2V and that was it.
l just finished building lights for my bike, you know the ones, 2*20W
quartz
halogen down lights
plus a 12V SLA battery.
l used a 7.0 amp hour battery(it does weigh 2.5 kgs so it isn't for weight
weenies)

Good to see that someone else has decided to build their own lights.......I
still reckon they are the best value for money. I have recently finished my
fifth set of lights for which i machined up an aluminium housing for a 35mm
halogen globe (20W). I made up a NiMh battery pack in an old water bottle
using 10 x 4500mAh batteries which are 4/3 AA size (basically a bit longer
and bit fatter than standard AA batteries). These are in series which gives
me a 12V, 4.5Ah battery.

I am also currently repacking a Vistalight nightstick for a mate whos old
one was pretty well had it. I am using 5 x sub-C NiMh cells (as per the
original) but I have bought 2700 mAh ones from Jaycar (www.jaycar.com.au)
that cost around $9 each. This means my mate gets a new nighstick for
around $45 bucks that has around 25% higher capacity than the original!!!!!
It is a pretty simple process that only involves some basic soldering.

If you are interested in having a look at my lights, they are at
http://members.ozemail.com.au/~drgagnon/lights_5.htm

Cheers,

Gags

"stu" wrote in message
...

do you really mean 35mm globes? l could only find 50mm.

Yep......you should be able to get the 35mm globes from a specialist
lighting store. I have also seen them in Jaycar. They are a bit more
expensive than the 50mm globes (close to $10) but I reckon they are worth it
for the reduction in size (Especially as the aluminium rod offcut that i
used to machine my housing was less than 50mm in diameter). I guess that
the downside is that they get a bit hotter than the 50mm globes (as they are
both 20W globes) but I don't seem to have a problem given the big aluminium
housing/heatsink that i mounted it in.

Cheers,

Gags