lighting battery - decisions decisions :-(

Dear group,

Since my twice 4 mile daily commute is in traffic I need decent lights.

I've weaned myself down to 10 watts of fluorescent for the front, and the
rear 12volt 21 watt incandescent may very shortly be replaced with a watt or
two of red LEDs (18 or 36 by my reckoning :-) ) - just as soon as I find a
suitable source ...
But I fancy venturing further afield on my bike (I certainly need the
exercise), so longer rides and maybe a spotlight to find my way off-road may
push my battery requirement back the other way ...

For the past few years I have repeatedly wasted between 10 and 14 quid on
12volt 7a/h SLA batteries. I used to reckon on getting a winter and a half
out of one, but last year's "bargain" from Toolstation is down to 1 a/h
after only one winter and the odd night ride.

I hate the idea of buying NiCds because of the environmental implications
and I already have a decent Maplin automatic SLA charger , so I am inclined
towards Cyclon cells for one last attempt at lead acid.
4 a/h of NiMH is comparable in price, but a smart NiMH charger is 55 quid
........

My other thought would be to profit from the boom in battery powered drills
and start using drill battery packs ...

What does the team think ?

yours, (currently forced to use emergency Cateye LED lights), of Bristol

On Tue, 01 Nov 2005 13:37:59 +0000, gentlegreen wrote:

My other thought would be to profit from the boom in battery powered
drills and start using drill battery packs ...

What does the team think ?

yours, (currently forced to use emergency Cateye LED lights), of Bristol
Someone on the Cycling Plus forum has taken a high-powered torch from
Maplins to pieces to make a headlight. Run time was a bit short, IIRC.

gentlegreen wrote:
I hate the idea of buying NiCds because of the environmental
implications and I already have a decent Maplin automatic SLA
charger , so I am inclined towards Cyclon cells for one last attempt
at lead acid. 4 a/h of NiMH is comparable in price, but a smart NiMH
charger is 55 quid .......

13.2V NiMH smart charger is £39.99 from Lumicycle*. A worthwhile
long-term investment, I would have thought (as also would be a complete
Lumicycle system). High-capacity NiMHs are getting cheaper all the time,
are lighter than NiCds and substantially lighter than lead acid.

* http://www.lumicycle.com/Product/Pro...?page=1&dep=88

There are other companies selling NiMH battery packs and chargers for non
rip-off prices as well.... sorry, the names escape me now.

Alternatively......
My main battery is a Lumi Li-ION, but I made an alternative/back-up
battery from 12 ordinary AA NiMH 2700mAh cells (via eBay) in a Maplin
battery box, so I could use my AA charger (since that's the only charger I
have for NiMH). Powers an over-volted 10W 12V MR11 halogen lamp for about
2 hours. It is hassle unpacking and charging all those cells, but it's a
relatively cheap solution if you already have a decent suitable charger.
One advantage over tagged cells is that each individual cell gets well
looked after (if the charger has independent monitoring).

~PB

"Pete Biggs" wrote in
message ...
gentlegreen wrote:
I hate the idea of buying NiCds because of the environmental
implications and I already have a decent Maplin automatic SLA
charger , so I am inclined towards Cyclon cells for one last attempt
at lead acid. 4 a/h of NiMH is comparable in price, but a smart NiMH
charger is 55 quid .......

13.2V NiMH smart charger is £39.99 from Lumicycle*. A worthwhile
long-term investment, I would have thought (as also would be a complete
Lumicycle system). High-capacity NiMHs are getting cheaper all the time,
are lighter than NiCds and substantially lighter than lead acid.

* http://www.lumicycle.com/Product/Pro...?page=1&dep=88

Thanks :-)

maybe I'll bite the bullet - though I notice now that CPC have a cheaper
charger and I would probably try to get my NiMHs from somewhere else - I
wonder what A/H lumicycle's are to justify the price ...



There are other companies selling NiMH battery packs and chargers for non
rip-off prices as well.... sorry, the names escape me now.

Alternatively......
My main battery is a Lumi Li-ION, but I made an alternative/back-up
battery from 12 ordinary AA NiMH 2700mAh cells (via eBay) in a Maplin
battery box, so I could use my AA charger (since that's the only charger I
have for NiMH). Powers an over-volted 10W 12V MR11 halogen lamp for about
2 hours. It is hassle unpacking and charging all those cells, but it's a
relatively cheap solution if you already have a decent suitable charger.
One advantage over tagged cells is that each individual cell gets well
looked after (if the charger has independent monitoring).

~PB

On Tue, 01 Nov 2005 16:59:49 GMT, gentlegreen wrote:

maybe I'll bite the bullet - though I notice now that CPC have a cheaper
charger and I would probably try to get my NiMHs from somewhere else - I
wonder what A/H lumicycle's are to justify the price ...

4 Ah, and I'm still getting over 3 actual useful (to 1.1V per cell, I
think, but maybe 1.0) after a few years of abuse.

My first home-brew light system used lead-acid batteries, but in the
first three years I went through one a year (basically). I then
changed over to NiCd, and got much better reliability from the
batteries.

I used battery packs intended for RC cars (6 cell, 7.2V driving dynamo
lights (ie nominally 6V) very happily). These are expected to have a
hard, hard life, at silly amps (I've drawn 50 amps from a sub-C NiCd
pack in my hovercraft) (but you won't get that out of a high capacity
NiMh - best you'll get from a sub-C cell is about 30 A), and they find
bike light situations very easy going.

(All past tense, because now I just use lumi.)

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

gentlegreen wrote:

maybe I'll bite the bullet - though I notice now that CPC have a
cheaper charger and I would probably try to get my NiMHs from
somewhere else - I wonder what A/H lumicycle's are to justify the
price ...

They don't seem to give the figure for the NiMH on the site. It's 4.4 Ah
for the medium Li-Ion. Good capacity to size/weight ratio also justifies
pricey batteries, if that's important to you. Lumicycle claim to use the
best cells available.

~PB

Pete Biggs wrote:
gentlegreen wrote:

maybe I'll bite the bullet - though I notice now that CPC have a
cheaper charger and I would probably try to get my NiMHs from
somewhere else - I wonder what A/H lumicycle's are to justify the
price ...

They don't seem to give the figure for the NiMH on the site. It's 4.4 Ah
for the medium Li-Ion. Good capacity to size/weight ratio also justifies
pricey batteries, if that's important to you. Lumicycle claim to use the
best cells available.

~PB

For years i have used a lumotec halogen dynamo headlight, running off a
standard 6volt roadlamp battery. Get about 3 weeks normal use out of it
for £2.99 from wilco.

"Pete Biggs" wrote in
message ...
gentlegreen wrote:
I hate the idea of buying NiCds because of the environmental
implications and I already have a decent Maplin automatic SLA
charger , so I am inclined towards Cyclon cells for one last attempt
at lead acid. 4 a/h of NiMH is comparable in price, but a smart NiMH
charger is 55 quid .......

13.2V NiMH smart charger is £39.99 from Lumicycle*. A worthwhile
long-term investment, I would have thought (as also would be a complete
Lumicycle system). High-capacity NiMHs are getting cheaper all the time,
are lighter than NiCds and substantially lighter than lead acid.

* http://www.lumicycle.com/Product/Pro...?page=1&dep=88

There are other companies selling NiMH battery packs and chargers for non
rip-off prices as well.... sorry, the names escape me now.

Alternatively......
My main battery is a Lumi Li-ION, but I made an alternative/back-up
battery from 12 ordinary AA NiMH 2700mAh cells (via eBay) in a Maplin
battery box, so I could use my AA charger (since that's the only charger I
have for NiMH). Powers an over-volted 10W 12V MR11 halogen lamp for about
2 hours. It is hassle unpacking and charging all those cells, but it's a
relatively cheap solution if you already have a decent suitable charger.
One advantage over tagged cells is that each individual cell gets well
looked after (if the charger has independent monitoring).


Just ordered from a seller on Ebay :-

10 off 3.3 A/h tagged sub-c NiMH r/c cells - £16.50 (which is roughly the
same "A/h per £" as 4.5A/h cyclon packs discounted at CPC) SLA is half as
much but of course they're cr*p

.... and a smart charger for £11.50 !

I should have done this yonks ago !

If I remember, I will report back to say whether these are the bargain they
appear to be.

I also ordered 20 ultrabright red LEDs to make a new rear light and hence
hopefully get over 2 hours' running time. They're rated at 5Cd but over 25
degrees which is a bit narrow, but I plan to mount them on an arc of
silvered plastic sheet.

I also ordered 20 ultrabright white LEDs as an experiment to see if I can
live with even less wattage - would be fine for cycletracks.

See - I've been quite restrained - my original intention was to use about 50
LEDs in my tail light :-)

I'm hoping to standardise on tamiya r/c power connectors and hence be able
to carry an emergency pack of AA NiMH - which is the most cost-effective and
readily available way of buying NiMH capacity ....

On Wed, 02 Nov gentlegreen wrote:

I'm hoping to standardise on tamiya r/c power connectors and hence be able
to carry an emergency pack of AA NiMH - which is the most cost-effective and
readily available way of buying NiMH capacity ....

Beware that a given cell will have a maximum current capacity, and if
you try and draw more current, the voltage falls off to practically
nothing.

One problem with the fixation on higher capacity is that the
manufacturers are tending to increase capacity at the expense of
current capability, imo. A big capacity might differentiate their
product, irrespective of whether it's actually useful. Consumer AA
cells might give you the capacity, but they might not give you the
current you want.

Plus, for an emergency pack, I'd have thought you're better off with a
pack of alkaline cells - no concerns about self discharge 'till next
decade.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|