Rear light that lasts

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roubaixtuesday
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Re: Rear light that lasts

Postby roubaixtuesday » 6 Jan 2019, 9:53am

Personally, I'd just say have a spare, and run one flashing, one constant. They're so light these days there's almost no downside.

I'm a convert to the usb charge/ built in battery type - my experience is that the lack of a potential leak point means they last fast longer, and lithium batteries are far better on recharge cycles than NiMH.

I use one of these as my spare. Excellent IME.

https://road.cc/content/review/205592-c ... micro-rear

alexnharvey
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Re: Rear light that lasts

Postby alexnharvey » 6 Jan 2019, 10:44am

roubaixtuesday wrote:Personally, I'd just say have a spare, and run one flashing, one constant. They're so light these days there's almost no downside.

I'm a convert to the usb charge/ built in battery type - my experience is that the lack of a potential leak point means they last fast longer, and lithium batteries are far better on recharge cycles than NiMH.

I use one of these as my spare. Excellent IME.

https://road.cc/content/review/205592-c ... micro-rear


I just take issue with your suggestion that lithium last far longer. I can leave a 2xaaa light on all day and certainly for longer than 2 hrs 50 mins. Possibly you meant that the lights fail in other ways? I've had some of the smart lights for 5 years and they live on the bike, outside. Since low self discharge NiMH batteries need recharged much less frequently, have a higher overall capacity and can be easily replaced if they do fail, the supposed recharge cycle advantage of lithium batteries such typically can't be replaced becomes pretty moot.

thelawnet
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Re: Rear light that lasts

Postby thelawnet » 6 Jan 2019, 11:14am

alexnharvey wrote:Back to batteries, am I right in thinking that the 1500-1800mAh capacity of two rechargeable NiMH AAA batteries is much greater than the capacity of most of the rechargeable internal battery lights that are now popular? I see a number of my colleagues recharging their lezynes daily which seems a terrible faff to me.


no.

aaa= 800 mAh. 1.2v

2*0.8*1.2 =1.92W

Lezyne 16340 around 600 mAh, 3.8V = 2.28W

Most likely the Lezynes are much brighter than cheap AAA lights

roubaixtuesday
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Re: Rear light that lasts

Postby roubaixtuesday » 6 Jan 2019, 11:26am

alexnharvey wrote:
roubaixtuesday wrote:Personally, I'd just say have a spare, and run one flashing, one constant. They're so light these days there's almost no downside.

I'm a convert to the usb charge/ built in battery type - my experience is that the lack of a potential leak point means they last fast longer, and lithium batteries are far better on recharge cycles than NiMH.

I use one of these as my spare. Excellent IME.

https://road.cc/content/review/205592-c ... micro-rear


I just take issue with your suggestion that lithium last far longer. I can leave a 2xaaa light on all day and certainly for longer than 2 hrs 50 mins. Possibly you meant that the lights fail in other ways? I've had some of the smart lights for 5 years and they live on the bike, outside. Since low self discharge NiMH batteries need recharged much less frequently, have a higher overall capacity and can be easily replaced if they do fail, the supposed recharge cycle advantage of lithium batteries such typically can't be replaced becomes pretty moot.


Sorry, obviously my post wasn't remotely clear. My bad.

In my experience:

1) Li batteries last many more charge cycles than NiMh.

2) Sealed unit lights are far more reliable than those with removable batteries, as water ingress at the seal is the commonest failure mode.

I emphasise that this is just my experience, it may well differ from others, sounds like yours is very different.

The light I linked to has been on the bike for three years, is used daily and charged weekly in winter, and ignored all summer. Still works as new.

My main point was intended to be that having a second light is probably a better idea than worrying about charge indicators on the light, given how reliable and light lights are now.

thelawnet
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Re: Rear light that lasts

Postby thelawnet » 6 Jan 2019, 12:03pm

roubaixtuesday wrote:In my experience:

1) Li batteries last many more charge cycles than NiMh.


This is I think not true, or at least not relevant for rear lights, where the battery is likely expected to outlast the light due to (relatively) infrequent charging. Eneloop NiMh cells have as good a cycle life as li-ion

2) Sealed unit lights are far more reliable than those with removable batteries, as water ingress at the seal is the commonest failure mode.


I think this is probably fair, in that a <£20 rear light with sealed li-ion battery is probably sufficiently cheap and disposable, more-or-less, that it makes as much sense to own a spare light, at ~50g with battery, than to carry spare batteries. The same concern is not applicable to front lights where battery life becomes a bigger issue.

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mjr
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Re: Rear light that lasts

Postby mjr » 6 Jan 2019, 4:58pm

roubaixtuesday wrote:Personally, I'd just say have a spare, and run one flashing, one constant. They're so light these days there's almost no downside.

Almost no downside to a flashing rear? You might as well wear a neon sign saying "I'm only a cyclist. Pass me in lane. If you get it wrong, I'll barely dent your car." See past discussions rather than make this one drifty.
MJR, mostly pedalling 3-speed roadsters. KL+West Norfolk BUG incl social easy rides http://www.klwnbug.co.uk
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roubaixtuesday
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Re: Rear light that lasts

Postby roubaixtuesday » 6 Jan 2019, 5:02pm

rather than make this one drifty.


No, You're definitely not drifting off topic there. No, sir!!

landsurfer
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Re: Rear light that lasts

Postby landsurfer » 6 Jan 2019, 5:02pm

Aldi Re chargeable lights are great ,,,, last for hours, charge via usb ... £8 ish a pair .... every time i see them i buy another set .... Lezyne copies ... probably from the same factory in Shinwyng Province.
The Road Goes On Forever ...

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freiston
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Re: Rear light that lasts

Postby freiston » 6 Jan 2019, 6:05pm

I would go for a battery lamp and use rechargeable batteries in it. Slow self-discharge rechargeables such as Eneloop will last ages even if you don't touch the light over the summer months. You can test them/top them up/swap them out or you can carry or purchase a replacement set as required - best of both worlds. There is a AA/AAA smart charger powered via USB available if you need to use USB

By way of explaining my reason why: rear light batteries last for ages. My main rear light is a dynamo light. I have a Smart 2xAAA back-up that rarely gets used (I use when I have panniers on because my rack-mounted light is obscured from the sides by the panniers - I've also used it in foggy weather) and it's still going strong on the batteries that it came with over two years ago. I also have a Cateye TL-LD600 that I bought in the 90s; it now only gets used on very rare occasions on my folding bike in the dark. It too uses 2xAAA that seem to last forever - currently has Eneloop rechargeables in it and I can't remember when I put them in. When the light was in regular use (in the 90s when I had a late shift job and so the light got used every day), I still only changed the batteries every few months.
Disclaimer: Treat what I say with caution and if possible, wait for someone with more knowledge and experience to contribute. ;)

SA_SA_SA
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Re: Rear light that lasts

Postby SA_SA_SA » 7 Jan 2019, 12:22pm

mjr wrote:...two cheap German back lights here and both have battery indicators on the on/off switches. Maybe battery indicators are required by StVZO standards.

Yes, they do:
slightly comically the one on my trailer lidl rear lamp are red which makes me think of red dwarf: the basic colour of your rear lamp is red and the colour of the low batt indicator is red so..... :)
I wonder why the rule-loving germans didn't add a rule to cover that? And why can't LED dynamo lamps be expected to cope with DC like the filament bulbs they replaced......
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MikeDee
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Re: Rear light that lasts

Postby MikeDee » 14 Jan 2019, 6:20pm

Check out the Cygolites. USB charged and long run times.

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[XAP]Bob
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Re: Rear light that lasts

Postby [XAP]Bob » 20 Jan 2019, 6:26am

SA_SA_SA wrote:
mjr wrote:...two cheap German back lights here and both have battery indicators on the on/off switches. Maybe battery indicators are required by StVZO standards.

Yes, they do:
slightly comically the one on my trailer lidl rear lamp are red which makes me think of red dwarf: the basic colour of your rear lamp is red and the colour of the low batt indicator is red so..... :)
I wonder why the rule-loving germans didn't add a rule to cover that? And why can't LED dynamo lamps be expected to cope with DC like the filament bulbs they replaced......

Many of them will cope with DC.
A shortcut has to be a challenge, otherwise it would just be the way. No situation is so dire that panic cannot make it worse.
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SA_SA_SA
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Re: Rear light that lasts

Postby SA_SA_SA » 21 Jan 2019, 11:23pm

[XAP]Bob wrote:...Many of them will cope with DC.

But ALL filament bulbs would and part of point of the Stzvo was surely the ability to simply swap one K-marked lamp for another: if all filament lamps worked on DC then logically for consistency all LED lamps should be required to do so: which would makes battery backups etc easier.... (and allow limping home on battery power if a generator fails.
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