Torpedo7's famous $99 5+10W halogen light set

[Friday]

TimC wrote:
> On 2006-10-17, Friday (aka Bruce)
> was almost, but not quite, entirely unlike tea:
>
>>Mike wrote:
>>
>>>Another possibility is the old lead-acid gel-cells, so long as you don't
>>>have too many hill-climbs (usually 6V or 12V only)
>>
>>I've gone to those Lithium-ion batterys they use in model planes.
>>They're expensive but the chargers for them are cheap, (voltage type
>>rather than current type.)
>
>
> If that reason is the justification for extra cost, that too is
> rediculous. It only takes a single transistor to transform a voltage
> detector to a current detector.

That might be so but you still need to measure the time it's been on or
have some sort of peak detection which adds complexity and cost. A
simple float voltage system simply needs a voltage regulator. In any
case the charger I got was very cheap and works very well.

>
>
>>Lithium batterys are about half the weight of
>>nickel batterys and about a quarter the weight of lead-acid gel cells.
>
>
> And a well maintained Li-Ion battery lasts a year or two, and a well
> maintained NiMH lasts several years.
>

I don't deny that, I have both, however the Lithium one is still much
lighter.

Friday

 

[Friday]

Donga wrote:
> TimC wrote:
>
>>On 2006-10-17, Mike (aka Bruce)
>> was almost, but not quite, entirely unlike tea:
>>
>>>Vincent Patrick wrote:
>>>
>>>>>All that's needed is to
>>>>>establish the cause, is it a cell or all of the cells? Take the
>>>>>appropriate action to repair/replace, and then recommend a decent
>>>>>charger that will ensure a long life for the rejuvenated battery.
>>>
>>>Amen! Even well-known brand-name lights can come with crappy dumb
>>>chargers that give poor battery life.
>>
>>Which is a crazy situation. You can make a crappy charger into a
>>reasonable charger for less than $5 of circuitry. Spend $300 on a
>>lighting system and end up with a crappy charger, WTF!?
>>
>>But it's their vested interest, because it forces people who don't
>>know better to repeatedly go out and buy new batteries. And most
>>people don't know better -- they just buy the cheapest money can buy.
>>
>>Those of us who know about the existance of smart vs dumb chargers
>>won't make the mistake a second time of buying a dumb charger, but we
>>probably are in the minority.
>>
>>--
>>TimC
>>Information wants to be beer, or something like that. --unknown
>
>
> OK, quick tip please for acquiring a smart charger, for the sake of
> completeness of the thread
> ;-) I too have trashed batteries!
>
> Donga
>

A good charger is the MW1768 from Master Instruments.
http://www.master-instruments.com.au/browse/Model/MW7168.html

 

[Friday]

Michael Warner wrote:
> On Tue, 17 Oct 2006 08:20:14 +0800, Mike wrote:
>
>
>>Except NiMH are even less tolerant of over-charging, so like to have a
>>good smart-charger. But they last a lot longer on one charge, so need
>>less cycles.
>
>
> NiMH cells are only damaged by over-charging if the charging current stays
> too high once they're charged. If you limit the current to < capacity/10 mA
> (e.g. 200mA for 2500mAh cells) they get slightly warm, since the input
> power is dissipated as heat, but they should tolerate it forever, and no
> intelligence is needed.
>

I'm not going to disagree, but everything I've read about batterys says
that heat kills them. More heat kills them quicker.

 

[roshea]

On the subject of "smart chargers" (which I know nothing about), would something like this be OK or is it way too far down the food chain? Any other suggestions for something to charge NiMH and maybe the occasional NiCad?

 

[TimC]

On 2006-10-17, roshea (aka Bruce)
was almost, but not quite, entirely unlike tea:
>
> On the subject of "smart chargers" (which I know nothing about), would
> something like 'this' (http://tinyurl.com/yx6lfl) be OK or is it way
> too far down the food chain? Any other suggestions for something to
> charge NiMH and maybe the occasional NiCad?

Looks good apart from being limited to charging either 2 or 4
batteries. If your LED light takes 3 AAAs, then you have no way of
charging them. If you chuck the undischarged unused 4th battery in
the charger, then the discharged battery on the same channel will
recieve a bad charge.

--
TimC
Tim flies like an arrow -- Donald Welsh on RHOD

 

[Michael Warner]

On Tue, 17 Oct 2006 14:11:55 +0800, Friday wrote:

> I'm not going to disagree, but everything I've read about batterys says
> that heat kills them. More heat kills them quicker.

I build my own chargers based on the 1/10th trickle principle, and I'm very
happy with the battery life I get.

--
Home page: http://members.westnet.com.au/mvw

 

[HughMann]

I too have noticed that the light is not as bright as it was. When connected to my 6V gel cell the light is crisp white.

Contrary to the advice on the box I opened it up the battery and had a peek.

SHIDA Battery. NiMH 4800mAH 6.0V

Made from 5 C size cells, 4 bundled together with the 5th laid diagonally accross the top all enclosed in shrink wrap.

Easy to pull the bottle apart, its only held together with heat set glue that yielded to a little push and twist from a 5mm screwdriver blade. There were a number of gaps in the glue that I thought could have let water in. Glue separated from plastic easily. No tricky bits inside, just remember to push the bits of foam rubber packing down the sides of the battery before pushing it all together or it will rattle.

Encouraged by my success with the battery I tackled the charger next. Was only able to measure "no load" output voltage and was alarmed to find that it was 11.2 volts. Suppose that the internal resistance of the battery pack is the determining factor here. Not a boffin.

SAFETY WARNING. Do not do this, dangerous voltages.

Opened up the charger and first impression was that it had been wet. Corrosion all over the solder joints.
The guts of the charger are junk. Small tranny, 4 discrete diodes as a bridge rectifier and a small electro cap, oh and the indicator LED.

Reworked all the solder joints and put it back together.

SAFETY emphasis. DO NOT OPEN THE CHARGER. Just believe what I have said.

From all that I understand (not much) about nimh batts & charging its a dumb fast charger that will cook batteries if left on too long. I plug the charger into a timer now. Just have to remember to disconnect before it gets a second dose tomorrow. Piggyback 2 timers gives a good margin of forgetfulness.

Anyone got a charger circuit thats a bit smarter than this poor attempt.

Cheers

Hugh

 

[Dave Hughes]

On Tue, 17 Oct 2006 14:10:28 +0800, Friday wrote:

> A good charger is the MW1768 from Master Instruments.
> http://www.master-instruments.com.au/browse/Model/MW7168.html

7168, in case anyone's googling and wondering, though the URL should point
you to the right model.

It's a reasonable charger, but I've had two fail for no apparent reason.
I'm currently using an el cheapo from Oatley Electronics that's working
OK, but a touch slow.

--
Dave Hughes | [email protected]
"It's 106 miles to Chicago, we've got a full tank of gas, half a pack
of cigarettes, it's dark, and we're wearing sunglasses"
- Elwood Blues

 

[Adam F]

"Michael Warner" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 17 Oct 2006 14:11:55 +0800, Friday wrote:
>
>> I'm not going to disagree, but everything I've read about batterys says
>> that heat kills them. More heat kills them quicker.
>
> I build my own chargers based on the 1/10th trickle principle, and I'm
> very
> happy with the battery life I get.
>


Yeah I use one of these:

http://www.jaycar.com.au/productView.asp?ID=MB3512

....and 10 2400mah jaycar nimh batteries in a pack - works fine, and when I
used to work at jaycar we'd leave them trickling for weeks on end, they'd
still last well over a year (don't get very hot).

I made a 10W+20W light, the 20 sure chews thru the juice but the 10 lasts
over an hour. Also a battery sometimes pops out of the (spring-loaded) pack
over the rough stuff


//Adam F

 

[Vincent Patrick]

TimC wrote:

> On 2006-10-16, Theo Bekkers (aka Bruce)
> was almost, but not quite, entirely unlike tea:
>> Hi Travis, Ni-cad's really do need a specific charger. They also need to
>> be totally discharged every six months or so. A good charger has the
>> regenerative discharge cycle built in.
>>
>> You can get good batteries or you can get cheap batteries. You can't have
>> both. e.g. If you buy a cordless drill for $40 there is a 50% chance the
>> batteries will fail in 12 months, 80% they will be dead within two
>> years.You can buy a 12V battery drill from Bunnings for $40. I paid $90
>> for replacement batteries for my 12V cordless drill from a wholesaler.
>> The original batteries were 12 years old. And yes, there is a huge
>> difference in power and performance.
>
> Someone earlier suggested the cheap NiMHs from Jaycar. I've read (not
> performed the experiment myself) that they last half the recharge
> cycles, and hold a smaller charge than what their labelling claims
> (Ones I have claim to be 1200mAH, whereas ones you get from other
> shops claim to be 2200mAH, so if 1200mAH is exaggerated, then you're
> looking at slightly cheaper batteries holding 1/4 of the charge.
> False economics, eh?)
>

I suggested Jaycar AA cells because they are low cost (even cheaper for ten)
and they sell ones which have tags for soldering, as well as the usual
nipple type. Tim, if you have 1200 mAh AA cells, then my guess is they are
a few years old, or you else you bought on price instead of price/capacity.

The last AA cells I bought from Jaycar were 2000 mAh, and currently the ones
that seem reasonable value in their catalogue are 2400 mAh. If soldering
isn't needed, then it is possible to pick up something useable from places
like Kmart, Big W, local camera shop, etc.

Anyway, for Travis, that's not important until the next set of Nicads die.
In the meantime, Travis, have fun with your replacement!

Cheers,

Vince

 

[Friday]

Vincent Patrick wrote:
> TimC wrote:
>
>
>>On 2006-10-16, Theo Bekkers (aka Bruce)
>> was almost, but not quite, entirely unlike tea:
>>
>>>Hi Travis, Ni-cad's really do need a specific charger. They also need to
>>>be totally discharged every six months or so. A good charger has the
>>>regenerative discharge cycle built in.
>>>
>>>You can get good batteries or you can get cheap batteries. You can't have
>>>both. e.g. If you buy a cordless drill for $40 there is a 50% chance the
>>>batteries will fail in 12 months, 80% they will be dead within two
>>>years.You can buy a 12V battery drill from Bunnings for $40. I paid $90
>>>for replacement batteries for my 12V cordless drill from a wholesaler.
>>>The original batteries were 12 years old. And yes, there is a huge
>>>difference in power and performance.
>>
>>Someone earlier suggested the cheap NiMHs from Jaycar. I've read (not
>>performed the experiment myself) that they last half the recharge
>>cycles, and hold a smaller charge than what their labelling claims
>>(Ones I have claim to be 1200mAH, whereas ones you get from other
>>shops claim to be 2200mAH, so if 1200mAH is exaggerated, then you're
>>looking at slightly cheaper batteries holding 1/4 of the charge.
>>False economics, eh?)
>>
>
>
> I suggested Jaycar AA cells because they are low cost (even cheaper for ten)
> and they sell ones which have tags for soldering, as well as the usual
> nipple type. Tim, if you have 1200 mAh AA cells, then my guess is they are
> a few years old, or you else you bought on price instead of price/capacity.
>
> The last AA cells I bought from Jaycar were 2000 mAh, and currently the ones
> that seem reasonable value in their catalogue are 2400 mAh. If soldering
> isn't needed, then it is possible to pick up something useable from places
> like Kmart, Big W, local camera shop, etc.
>
> Anyway, for Travis, that's not important until the next set of Nicads die.
> In the meantime, Travis, have fun with your replacement!
>
> Cheers,
>
> Vince
>
>
Be aware that some cells have stainlees steel tabs and others have
tinned tabs. The stainless ones are designed to be spot welded and can't
be easily soldered. The tinned ones should should be given a light rub
with a fine abrasive before you solder them as the tin has some sort of
coating that the solder won't stick to very well.

Friday

 

[Travis]

Vincent Patrick wrote:

> Anyway, for Travis, that's not important until the next set of Nicads die.
> In the meantime, Travis, have fun with your replacement!

Its a NiMH bottle type pack by the way, not NiCd.

So what's the best way to keep a NiMH battery pack alive? Would I
increase or decrease its lifespan with the occasional deep discharge?

If I put my el-cheapo charger as supplied with the light set onto a
timer, so for instance it would only charge batteries for, say, 8 hours
a night and then a 1 hour topup during the day (only on the weekend, my
bike is at work on weekdays), would that help? It would certainly
prevent overcharging if I forget to unplug it and it runs all weekend.

Various articles on the net which I read a while back not only say
there is no "memory effect" in NiMH, but also that the memory effect is
largely an urban myth for NiCd as well, having been observed only in
some very specific high performance applications, like on satellites.

Travis

 

[TimC]

On 2006-10-18, Travis (aka Bruce)
was almost, but not quite, entirely unlike tea:
>
> Vincent Patrick wrote:
>
>> Anyway, for Travis, that's not important until the next set of Nicads die.
>> In the meantime, Travis, have fun with your replacement!
>
> Its a NiMH bottle type pack by the way, not NiCd.
>
> So what's the best way to keep a NiMH battery pack alive? Would I
> increase or decrease its lifespan with the occasional deep discharge?

"contentious issue". Whatever you read about NiMHs, someone disagrees
with it and writes to diametrically opposite.

> If I put my el-cheapo charger as supplied with the light set onto a
> timer, so for instance it would only charge batteries for, say, 8 hours
> a night and then a 1 hour topup during the day (only on the weekend, my
> bike is at work on weekdays), would that help? It would certainly
> prevent overcharging if I forget to unplug it and it runs all weekend.
>
> Various articles on the net which I read a while back not only say
> there is no "memory effect" in NiMH, but also that the memory effect is
> largely an urban myth for NiCd as well, having been observed only in
> some very specific high performance applications, like on satellites.

That NiCd memory effects were because of poor chargers of the time
overcharging because they always assumed the battery was deep
discharged? Yep, you've read the same article(s) as me.

--
TimC
I want to ride my bicycle, I want to ride my bike.
I want to ride my bicycle, I want to ride it where I like. - Freddy Mercury

 

[HughMann]

Be aware that some cells have stainlees steel tabs and others have
tinned tabs. The stainless ones are designed to be spot welded and can't
be easily soldered. The tinned ones should should be given a light rub
with a fine abrasive before you solder them as the tin has some sort of
coating that the solder won't stick to very well.

Friday

Yep, its a trap. To clean up the tinned tabs scrub lightly with fine steel wool then wipe over with neat "Rust Converter" on a cotton bud. Available from Supa Cheap or Repco. Be careful as its phosphoric acid and will cause injury. Read the safety precautions. This also works for soldering wires to nipple type batteries.
A larger soldering iron, at least 25w, will allow a quick neat job. A small electronics size iron will have the heat "sucked" out of it by the mass of metal in the battery and the solder wont flow properly.

Our resident electronics boffins appear to be absent and we dont want a repeat of the flame war that started when a couple of personalities from aus. electronics visited us early in the year. Will have to wait for a smarter charger circuit or modification suggestions.

Guessing here but I assume that if the voltage out of the charger was reduced from 11.2 volts DC with a series diode (or 2) the charging would be slower and therefore less heat and strain on the batteries. Will wait for a more educated response.

** TRAVIS ** I only charge my battery for 5 hours every couple of days. It gets Very hot if left longer than that. After 5 hours its up to 6.8 volts no load so I suppose thats approximately charged.

Cheers

Hugh

 

[Travis]

TimC wrote:

> "contentious issue". Whatever you read about NiMHs, someone disagrees
> with it and writes to diametrically opposite.

Especially on Usenet.

> > If I put my el-cheapo charger as supplied with the light set onto a
> > timer, so for instance it would only charge batteries for, say, 8 hours
> > a night and then a 1 hour topup during the day (only on the weekend, my
> > bike is at work on weekdays), would that help? It would certainly
> > prevent overcharging if I forget to unplug it and it runs all weekend.

I'd like your opinion on this one actually.

>From what I have heard, rechargeable batteries are killed by the heat
which builds up in them when they get overcharged.

Using a power timer I could set it up so the battery could be recharged
in short bursts. 8-10 hours recharge a night (as per the instructions
with the light set) but I could program the timer to give the battery a
break periodically, i.e. 3 hours solid then an hour off, or 1.5 hours
and half an hour off.

Any opinion on whether or not this would work?

Am I really better off spending all that money on a proper smart
charger from an electronics or auto place?

My attitude toward this unit when I bought it was I hoped to get a
couple of years of use out of it and then I could buy a new unit. LEDs
are getting better and cheaper all the time, as are batteries. In two
years time high powered LED powered lights with really good batteries
and smart chargers will cost a lot less than they do now. I can't
bring myself to spend $300 on a really good light today knowing that in
a couple of years I'll be able to get something much better for much
less money.

Something like a Light and Motion Vega would probably suit me. No
doubt some cheap online mob will be selling an equally capable product
in a year or two for under $100. When they do, I'll buy two.

Travis

 

[TimC]

On 2006-10-18, Travis (aka Bruce)
was almost, but not quite, entirely unlike tea:
> TimC wrote:
>> > If I put my el-cheapo charger as supplied with the light set onto a
>> > timer, so for instance it would only charge batteries for, say, 8 hours
>> > a night and then a 1 hour topup during the day (only on the weekend, my
>> > bike is at work on weekdays), would that help? It would certainly
>> > prevent overcharging if I forget to unplug it and it runs all weekend.
>
> I'd like your opinion on this one actually.
>
>>From what I have heard, rechargeable batteries are killed by the heat
> which builds up in them when they get overcharged.
>
> Using a power timer I could set it up so the battery could be recharged
> in short bursts. 8-10 hours recharge a night (as per the instructions
> with the light set) but I could program the timer to give the battery a
> break periodically, i.e. 3 hours solid then an hour off, or 1.5 hours
> and half an hour off.

They heat up pretty quickly if they are individual cells. If a
battery pack, I'd probably be sticking to less than an hour. Then
measure how long it takes to get back to room temperature.

Note that the surface temperature may well not represent the internal
temperature either. When cooling down, the surface has to stay hot
while the internals are hot, so measuring the cooldown time should be
easier.


You are saying 3 hours initially instead of 8-10? Makes sense,
because the 8-10hours is only for substantially discharged batteries.

> Any opinion on whether or not this would work?
>
> Am I really better off spending all that money on a proper smart
> charger from an electronics or auto place?

Yep.

> My attitude toward this unit when I bought it was I hoped to get a
> couple of years of use out of it and then I could buy a new unit. LEDs
> are getting better and cheaper all the time, as are batteries. In two
> years time high powered LED powered lights with really good batteries
> and smart chargers will cost a lot less than they do now. I can't

You reckon? The cycle seems longer than that. And it looks like
companies are never willing to release smart chargers as default.
Maybe it'll improve.

--
TimC
"I looked back and bikes and riders were flipping in the air. There
must have been 20-30+ riders in the pile."
-- overheard after Early Bird 4/5 race