Batteries

itboffin

Apart from the silly money I spend on inner tubes i'm now putting away a tidy sum on batteries, i've dabbled with rechargeable before but they never seemed as bright, does anyone have experience of using hi powered rechargeable AA, like 2700 or 2900 mAh

DonDaddyD

Maplins own brand. Check em out.

amaferanga

Vapextech

I believe that rechargeables will give a constant brightness before dying quite rapidly, where as with alkaline batteries the brightness will start to fall off much quicker.

I use the 2900mAh with some of the Instant as emergency spares.

SlowingDown

I use GP Recyko AAs in my Hope Vision1. They are 2100mAh but slow drain meaning they wont loose anything like the charge of higher mAh, normal rechargeables while not in use.

I'm really pleased with the brightness and lifespan per charge and at about five and a half quid for 4 they were a bargain.[/url]

jejv

itboffin wrote:

Apart from the silly money I spend on inner tubes i'm now putting away a tidy sum on batteries, i've dabbled with rechargeable before but they never seemed as bright, does anyone have experience of using hi powered rechargeable AA, like 2700 or 2900 mAh

What kind of lights have you got ? What's the current drain ? How long is your commute ? What size cells do you use ?

[OK, I could probably work this out from the forums, but I'm lazy]

candlepower forums could be a better place to ask. ( http://www.candlepowerforums.com )

Personally, I want a cell with a datasheet, otherwise I'm not going to believe what's written on it. I usually go for GP ( . http://www.gpbatteries.com/html/front/index.html ) But I'll buy no-brand if it comes with a datasheet The numbers on GP consumer cells are - in a normal way of speaking - lies, but you have the datasheet.

If you have a long commute with multi-amp lights that use multiple cells, you want to start worrying about the charger as much as the cells. You'd want fairly balanced cells. I think it t helps to find a good deal, and buy loads of similar cells at the same time.

Cheap chargers, and some very expensive chargers, will happily overcharge cells, reducing capacity/lifetime. candlepower again probably the best place to look to find decent chargers. I'd suggest maha ( http://www.mahaenergy.co.uk ) Some of their stuff is available cheaper elsewhere in the UK, and much cheaper in the US.

I think I want a charger that tells me when my cells are worn out - that gives me a capacity reading on discharge. If you're using multiple cells, the weakest cell determines your run-time, and that weakest cell may even be subject to charge-reversal damage if you run the set of batteries low.

Low self-discharge NiMH cells seem to have lower resistance too.

Specialized Needs

itboffin wrote:

Apart from the silly money I spend on inner tubes i'm now putting away a tidy sum on batteries, i've dabbled with rechargeable before but they never seemed as bright, does anyone have experience of using hi powered rechargeable AA, like 2700 or 2900 mAh

Yep. My experience is that some of my higher capacity AAs are too wide to fit my new lights (14.5mm instead of 13.5mm), these are my Vapextech 2900mAh. The older Vapextech 2700mAh are fine. That said, the batteries are great. The charger is in lots of ways more important (I'm sure someone will be along in a moment to recommend one or two) to prevent damage to the batteries.

I'm trying Maplin ones next just so I can take the batteries back if they don't fit :?

jejv

duncedunce wrote:

My experience is that some of my higher capacity AAs are too wide to fit my new lights (14.5mm instead of 13.5mm),

That's a problem with the lights, not with the cells.

That would be because the designers couldn't be @rsed to read any battery standards docs, or look at - say - the duracell website ( http://www.duracell.com/procell/design/cavity.asp )

I imagine this stuff is designed by asking arround the office for some AAs, and trying to measure them with plastic vernier calipers.

Specialized Needs

jejv wrote:

duncedunce wrote:

My experience is that some of my higher capacity AAs are too wide to fit my new lights (14.5mm instead of 13.5mm),

That's a problem with the lights, not with the cells.

That would be because the designers couldn't be @rsed to read any battery standards docs, or look at - say - the duracell website ( http://www.duracell.com/procell/design/cavity.asp )

I imagine this stuff is designed by asking arround the office for some AAs, and trying to measure them with plastic vernier calipers.

That may be so, but the end result is the batteries don't fit

This was the Smart bSpoke 1/2 watt lights. The two sets of lights I bought 6 months back, same model, make etc, fitted the wider batteries fine; don't know why they changed them :roll:

jejv

duncedunce wrote:

jejv wrote:

duncedunce wrote:

My experience is that some of my higher capacity AAs are too wide to fit my new lights (14.5mm instead of 13.5mm),

That's a problem with the lights, not with the cells.

That would be because the designers couldn't be @rsed to read any battery standards docs, or look at - say - the duracell website ( http://www.duracell.com/procell/design/cavity.asp )

I imagine this stuff is designed by asking arround the office for some AAs, and trying to measure them with plastic vernier calipers.

That may be so, but the end result is the batteries don't fit

This was the Smart bSpoke 1/2 watt lights. The two sets of lights I bought 6 months back, same model, make etc, fitted the wider batteries fine; don't know why they changed them :roll:

Send the stuff back, and state that it's mis-described. ( I guess it says what size cells it supposedly takes).

Had a portable vellemann osciloscope once, supposed to run off 4 AA's - rechargeables wouldn't fit. I was curious. When I figured out the problem, I sent it back. Huh!? This is test equipment ! They still can't be @rsed to get it right.

artaxerxes

Also have a look at Sanyo Eneloops or Uniross Long life Hybrios. Comparison table here

FeynmanC

amaferanga wrote:

Vapextech

I believe that rechargeables will give a constant brightness before dying quite rapidly, where as with alkaline batteries the brightness will start to fall off much quicker.

I use the 2900mAh with some of the Instant as emergency spares.

+1 last much longer and are brighter than duracells on my L2D. Good price and their intelligent charger seems good value too.

Headhuunter

It's most likely a problem with your charger than your batts, although a cheap charger will damage batteries. I have learned (from this forum) that standard fast chargers pump a standard charge into batteries without any consideration for how far discharged they are. This generally results in overcharging and even with NiMH batts, development of the "memory effect", which eventually means the batteries never charge to their full potential. I bought a this charger - http://www.batterylogic.co.uk/technolin ... -bl700.asp

It works out how depleted the battery is and charges with exactly the right amount of energy. You can also select a slower charge rate which is less damaging to the battery. It also has discharge and refresh modes. Discharge mode discharges the batteries to near zero before recharging to break the memory effect. Refresh is good for tired batteries - it discharges and recharges continuously until it fails to detect an increse in the mAh value of the batteries.

I bought a Fenix L2D torch to use as a front light a few months ago and it didn't last 20 mins with my rechargeables charged by my cheap fast charger, however after a complete refresh in the intelligent charger they last several hours before they dim.

Properly maintained recheargeables are actually better than standard batteries as they retain their full output for longer before dropping off suddenly (which actually can be a disadvantage if you're out on the road and suddenly your lights dim). Standard, non rechargeables dim slowly and steadily throughout their life, which means even they day after putting them in the light, they may already be dimmer.

il_principe

Wow they even make pedants for batteries.

Headhuunter

Il Principe wrote:

Wow they even make pedants for batteries.

Ooh you bitch! Seriously though, the "intelligent charger" has been a revelation to me. Another thing that it allows you to do is use batteries with a similar mAh value together - for example 2x2500 mAh in the same light. Even though you may have bought 2900 mAh batteries, once you put them in the intelligent charger you'll realise that in reality they are more like 2700 or something and possibly lower if you've been using them for a while. It's a good idea to use batteries of the same mAh as it prevents strain on one battery and means the light or whatever lasts longer. Oh dear, I've turned into a bettery nerd...

Headhuunter

That starry bit was suppose to say b-i-t-c-h, biatch, female dog (let's see if any of those get through)....

wgwarburton

itboffin wrote:

Apart from the silly money I spend on inner tubes i'm now putting away a tidy sum on batteries, i've dabbled with rechargeable before but they never seemed as bright, does anyone have experience of using hi powered rechargeable AA, like 2700 or 2900 mAh

On unsophisticated lights brightness tends to be linked to voltage rather than capacity. The figures quoted are the marketing team's claim for how long the batteries might last.

I don't know how much info you want, here. This gets pretty involved quite quickly and a detailed discussion of discharge curves, ultimate capacity and regulation is probably beyond the scope of this board, as well as beyond my incomplete knowledge on the topic.

Here are some pointers on the right things to think about (IMHO):

"Regular" batteries (alkaline, typically) will output about 1.5 volts for most of their useful life, so a set of four will usually be driving your light at around 6V.
Rechargeables (NiCad, NiMh, hybrid) will output 1.2V, so a set of four will be putting out 4.8V.
If your light is designed to work with either it will have some circuitry inside to drive the emitter (LED, Halogen etc) at a steady voltage for a range of inputs ("regulated"), this gives more consistant output and longer "bulb" life (although if it is badly designed it can waste power).

Quality of batteries varies greatly (see other posts), and so does the quality of chargers.

Your rechargeables will last longer if they are not charged too quickly- good chargers monitor each battery seperately to make sure it doesn't get overheated or continue to be charged when it's full.

Standard Nicad/NiMh rechargeables won't hold charge well- leave them in your backpack for a few weeks and they'll lose a significant amount of charge. The new "hybrid" designs address this but at the cost of lower headline capacity.

So, find out if your lights will work well with rechargeables, cost up a good charger (Maha? Technoline?) and some quality batteries and work out whether it's worth your while to switch given your known pattern of usage.

As another datapoint, I have a Cateye BL300 (4xAA), and it doesn't seem to work well with four rechargeables. I set up an external battery holder so I can run it from five NiMhs and got a multi-channel (Technoline) charger, so I can recharge the extra cell on its own.
I carry a set of four Energizer Lithiums as spares- they have a long shelf-life, are light(!) and work well without the added complication of the external holder.

I also recently bought some Maplin hybrid AAAs for my rear light- I'd been holding off using regular NiMhs there because of the self-discharge. Working OK so far.

Hope this helps!

Cheers,
W.

wgwarburton

Il Principe wrote:

Wow they even make pedants for batteries.

We have only scratched the surface.... This isn't the "battery pedant" version of the thread, this is the highly superficial, consumer aligned, oversimplified, non-technical version.... If you think this is bad, you should tune out now before things get really dull!!!!

No-one even mentioned temperature, yet, or matching sets of batteries (edit headhuunter's just brought that into play...), or conditioning...

Cheers,
W.

sarajoy

WGWarburton wrote:

No-one even mentioned temperature, yet, or matching sets of batteries (edit headhuunter's just brought that into play...), or conditioning...

Cheers,
W.

Just tell us the best value for money rechargeables set for bike lights, and we're done

(I've just had a normal alkaline battery barely last a few days in my bog standard cateye front light... it was an IKEA one though...)

Headhuunter

sarajoy wrote:

WGWarburton wrote:

No-one even mentioned temperature, yet, or matching sets of batteries (edit headhuunter's just brought that into play...), or conditioning...

Cheers,
W.

Just tell us the best value for money rechargeables set for bike lights, and we're done

(I've just had a normal alkaline battery barely last a few days in my bog standard cateye front light... it was an IKEA one though...)

It's just not as simple as that but for basics get an intelligent charger (Technoline - see above) and some Vapextech 2900 mAh rechargeables (again above) and you're off to a good start...

beegee

I have Li-ion 3.7 v 2400 mah 18650 (I think that's eveything it says, no, wait a minute, 'do not throw into fire...') rechargeable batteries with pcb. I find thay they fade quite noticeably over the hour that they are lit. I thought that rechargeables didn't do that. Also it says that the pcb life is about 10 years. Is that the same as the life of the battery ?

OldSkoolKona

Amazed by the knowledge that lurks on the forum, chapeau to jejv, WGW and HH

Interesting subject, have all but ditched using rechargeables for my lights because they seemed to go dim pretty quickly, now I can understand why.

sarajoy

Headhuunter wrote:

sarajoy wrote:

WGWarburton wrote:

No-one even mentioned temperature, yet, or matching sets of batteries (edit headhuunter's just brought that into play...), or conditioning...

Cheers,
W.

Just tell us the best value for money rechargeables set for bike lights, and we're done

(I've just had a normal alkaline battery barely last a few days in my bog standard cateye front light... it was an IKEA one though...)

It's just not as simple as that but for basics get an intelligent charger (Technoline - see above) and some Vapextech 2900 mAh rechargeables (again above) and you're off to a good start...

And these put out close enough to 1.5V?

I've had 1.2V rechargeables in the past which simply haven't worked with what I'd been intending to use them for. Irritating, that, I forget what they were, though...

wgwarburton

sarajoy wrote:

And these put out close enough to 1.5V?

I've had 1.2V rechargeables in the past which simply haven't worked with what I'd been intending to use them for. Irritating, that, I forget what they were, though...

Sorry, no. They'll be 1.2V, it's a consequence of the chemistry of the cell.

There's a workaround where you use five rechargeables to replace four "standard" cells but most equipment won't let you do this (probably to stop you putting five 1.5V cells in!).
As I said above, some stuff is designed to work with both rechargeable and "standard" batteries, but it makes the designer's job harder and generally costs more, so it's an easy way to cut corners.

Cheers,
W.

Roastie

Headhuunter wrote:

"intelligent charger"

Brings back memories - back in the day my Ericsson GH197 (which I still have) came with an Intelligent Charger that would fully discharge the NiCd battery before starting the charge cycle. But you had to take the battery off to do this...

wgwarburton

beegee wrote:

I have Li-ion 3.7 v 2400 mah 18650 (I think that's eveything it says, no, wait a minute, 'do not throw into fire...') rechargeable batteries with pcb. I find thay they fade quite noticeably over the hour that they are lit. I thought that rechargeables didn't do that. Also it says that the pcb life is about 10 years. Is that the same as the life of the battery ?

Something odd going on here- Li-ions have a flat output from about 10% to 90% discharge, so after an initial switch-on surge, they shouldn't fade significantly until they are nearly flat.
Maybe there's something wrong with the control board (I assume that's what the pcb is?).
Cheers,
W.

SmellTheGlove

If you're using LED lights their brightness is related to the available current, not the voltage, so other things being equal, 4 x1.2V cells (e.g. rechargeable NiMH) will give the same brightness as 4 x 1.5V (e.g. alkaline).
That's all I know (about this topic - don't start me on anodising or nob rash).

japsy

WGWarburton wrote:

beegee wrote:

I have Li-ion 3.7 v 2400 mah 18650 (I think that's eveything it says, no, wait a minute, 'do not throw into fire...') rechargeable batteries with pcb. I find thay they fade quite noticeably over the hour that they are lit. I thought that rechargeables didn't do that. Also it says that the pcb life is about 10 years. Is that the same as the life of the battery ?

Something odd going on here- Li-ions have a flat output from about 10% to 90% discharge, so after an initial switch-on surge, they shouldn't fade significantly until they are nearly flat.
Maybe there's something wrong with the control board (I assume that's what the pcb is?).
Cheers,
W.

I think the pcb relates to the protection circuit for the cells to prevent overcharging, overdischarging and shorts.

The light output fades probably due to using an unregulated driver circuit (of the torch/light).

itboffin

[b]SmellTheGlove[/b] wrote:

If you're using LED lights their brightness is related to the available current, not the voltage, so other things being equal, 4 x1.2V cells (e.g. rechargeable NiMH) will give the same brightness as 4 x 1.5V (e.g. alkaline).
That's all I know (about this topic - don't start me on anodising or nob rash).

You must be a real hit with the ladies :P

sarajoy

WGWarburton wrote:

sarajoy wrote:

And these put out close enough to 1.5V?

I've had 1.2V rechargeables in the past which simply haven't worked with what I'd been intending to use them for. Irritating, that, I forget what they were, though...

Sorry, no. They'll be 1.2V, it's a consequence of the chemistry of the cell.

There's a workaround where you use five rechargeables to replace four "standard" cells but most equipment won't let you do this (probably to stop you putting five 1.5V cells in!).
As I said above, some stuff is designed to work with both rechargeable and "standard" batteries, but it makes the designer's job harder and generally costs more, so it's an easy way to cut corners.

Cheers,
W.

Hah, fair enough!

So that Technoline charger with Vapextech batteries - it's a clever enough charger that once set for chosen charge mode and current, you can shove batteries at varying levels of charge in there and it'll just top them up without overcooking them?

alfablue

sarajoy wrote:

Headhuunter wrote:

sarajoy wrote:

WGWarburton wrote:

No-one even mentioned temperature, yet, or matching sets of batteries (edit headhuunter's just brought that into play...), or conditioning...

Cheers,
W.

Just tell us the best value for money rechargeables set for bike lights, and we're done

(I've just had a normal alkaline battery barely last a few days in my bog standard cateye front light... it was an IKEA one though...)

It's just not as simple as that but for basics get an intelligent charger (Technoline - see above) and some Vapextech 2900 mAh rechargeables (again above) and you're off to a good start...

And these put out close enough to 1.5V?

I've had 1.2V rechargeables in the past which simply haven't worked with what I'd been intending to use them for. Irritating, that, I forget what they were, though...

Actually, NiMH rechargeables will put out more than 1.2v despite the 1.2 stated, and 1.5v alkaline cells are actually only putting out 1.2v or less from only 25% through their discharge.


Anyway, NiMH will be far superior in an LED light, and the simple, cheap answer is Vapextech 2900mah batteries (which will actually output about 2500mah), about £5 for 4 delivered, and a Vapextech LCD World Charger (its a smart one) for about £15. Better charger is the Technoline BL-700 (about £27), the BC-900 (about £42) or the Maha Wizard One (£49), but all smart chargers should sense battery voltage and temperature and stop charging before damage is done, the more expensive models add in custom charge rates, discharge, conditioning and analysis programmes.

wgwarburton

sarajoy wrote:

So that Technoline charger with Vapextech batteries - it's a clever enough charger that once set for chosen charge mode and current, you can shove batteries at varying levels of charge in there and it'll just top them up without overcooking them?

The default action is to top them up and then throttle back the current to keep them full, so you don't even need to set it- just switch on & pop them in.
It has additional modes for discharging, and refreshing, too- one of the handy features is that you can pop in some cells you are unsure of and set it to refresh them- it'll discharge and recharge them until they stabilise, clearing any "memory effect" that they might be showing, and then display the capacity they are actually delivering. As well as identifying failing cells this also lets you group them by capacity: as headhuunter pointed out, a set is limited by the weakest member and you risk damaging that one further if you use it with good ones, so it's better to use cells that have similar capacity together.
The BL-700 does AAs and AAAs, up to four at a time. There are other chargers that have similar functions that offer other options (eg there's a Maha pro model that will do up to eight cells and a couple of 9V batteries at the same time. Costs more, though :-) )

Cheers,
W.