Ebike light powered by 18650 pack

[damitamit]

Looking at alternatives to a dynamo setup for audax and got me thinking about ebike stvzo lights...

I bought one of these on amazon: https://www.trustfire.com/products/trustfire-eb02-battery-box and already have some 3000mah 18650s to test with. Will get some 3500mah protected cells if it works.

Any reason it wouldn't power a ebike light like the Lezyne PRO E115 SWITCH (https://ride.lezyne.com/collections/led-lights-stvzo/products/ebike-power-stvzo-pro-e115-switch)? This is STVZO and has a switch for 2 modes, 115 lux and 30 lux. Sounds perfect for long audaxing with a spare set of 18650s.

Or the B&M IQ-XS E: https://www.bumm.de/en/products/e-bike-scheinwerfer/parent/167/produkt/167r42ts-01.html?

Or the Spanninga axendo-60: https://spanninga.com/product/axendo-60/

These all take minimum 6v, so I think the 8.4v (7.4v) pack would work fine? I assume they're just dumb light units, so if I get protected 18650 cells this should deal with any overdischarge issues.

Thoughts?

[freeflow]

 I too use the Trustfire battery box with 4x3400mah 18650 to power my phone and to drive one light. 


The light I use is a


https://www.bumm.de/en/products/e-bike-scheinwerfer/parent/164/produkt/164r60ts7-01.html?


The output from this light is quite exceptional.


When running both the phone and the light at night I get about 5 hours 15 minutes of runtime before the light cuts out.


I also run a second AA powered light so that when the IQX-E cuts out I still have lights.


I find 2 sets of 4x18650 3400mah batteries are sufficient for a 300km ride.

[damitamit]

Oh great, that's promising.

That sounds like a lengthy runtime seeing as the IQ-X is 150 lux and a phone probably draws quite a bit of current.

Do you use protected cells?

[numbnuts]

Been using this one off ebay, so far so good
https://www.ebay.co.uk/itm/133978920404?_trkparms=ispr%3D1&hash=item1f31c415d4:g:484AAOSw7klcwAUT&amdata=enc%3AAQAGAAAA4P%2BqaY3cSzdMYdUrb1FtX2TKLL5VdFb2PRjC764mW85VHFO%2BH%2B5xpSPjYwJ9OBogibEJg67QHHLAsGu732iI9o38K8Nphb2qmcJx03W3DGcVEL5aXF17JhLQwyzMqaeZXqhjl2jZ6WO70eNzT6l%2FkLcvxDGQzKTvtpRbJtT0ugAFoOYDct%2BuwN3ncLbhokNL3o6CRZn0%2BJ6BmHTw4qqg5RApQqRJ25kdqpHBt7jxq5epTtDEFt2%2FrFUk2ioMNJ6BLsy%2BNsnebbLAVOvAFVFQot37C1L7Wn0BcgcsjJ3iVW%2F4%7Ctkp%3ABFBM5rz1mZFg

[freeflow]

Do you use protected cells?

Yes.  That data is with protected cells.  But I think the Trustfire also has protection built in.

[sojournermike]

I also use the IQ-X E e-bike light with a 4x18650 pack. The light is excellent and I get very good duration from 4x3500mah cells. The light will actually run OK down to 5V or thereabouts, but a 2S2P pack should shit down at about 5.6v. I usually run a second lamp to avoid sudden blackness and for reliability.

The light is excellent and bar mountings as well as fork are available. It’s supposed to have 150 lux with a shaped beam.

https://www.bumm.de/en/products/e-bike-scheinwerfer/parent/164/produkt/164r60ts7-01.html?

Mike

[damitamit]

Update on this. Picked up a cheap B&M IQ-XS E ebike light on evilzon (it was mislabelled as a dynamo light)...



Connected to the 8.4V battery box, it draws 320-330mA. With the 18650s in the box being 3500mah in 2s2p, that calculates to 21.2 hours. Will it be less in reality? Even if its 20 hours, that's pretty decent. With a spare set of batteries that's a lot of night riding at 70 lux.

I was wondering what the translucent bit is at the back of the light. I thought it was a button but must just be a light sensor for the DRL. If i cover it I get the 330ma draw above but uncovered, it draws 200ma.

[Kim]

I think it's a switch in the dynamo version?  Perhaps they assume that on an e-bike, switching will be via the e-assist system.


This e-bike light with an off-the-shelf battery pack approach seems to be a good way to get dynamo light build quality in a battery light...

[Frank9755]

This looks really good. 

A couple of years ago I looked into using e-bike lights with power banks.  It would be for long distance events so I wanted to standardise batteries for interchangeability and minimise charging kit.

Most e-bike lights don't work at 5V (I tested a B+M and it doesn't) but some do.  I got a couple of fairly cheap RFR ones (50 and 90 lux) but the beam pattern isn't as good as B+M so I haven't really used them.  I then found something else which worked well, so didn't add to my e-bike light collection.  However, the other ones that work at 5V are Supernova, which are meant to be good but very expensive. 

Going to 8.4V massively widens the choice and would be ideal for rides up to PBP-length where you wouldn't need to recharge. 

I really can't justify getting another light just now so should stop reading this!

[damitamit]

It's definitely a rabbit hole!

Got one of these coming: https://ride.lezyne.com/products/ebike-power-stvzo-pro-e115-switch. Has a switch and 115/35 lux output, which could work quite well for long audax.

Picked up a Lumintop B01 flashlight on aliexpress which takes a 21700 cell and has a "designed according to STVZO" beam. Yet to try it on the road but it has a 11 hour medium 260 lumen mode which could work well.

[Lightning Phil]

Interesting.  What’s the weight of the battery pack?

[damitamit]

Interesting.  What’s the weight of the battery pack?

127g empty.
314g with 4 3000mah Sofirn 18650s.

[Frank9755]

It's definitely a rabbit hole!

There's something addictive (to me at least) about finding something that was designed for a slightly different purpose and tweaking it to make it work better than the normal options for a related purpose.  I wish I could get help for it!

This is the one that I would like to buy:
https://winstanleysbikes.co.uk/supernova-m99-mini-pro-25-e-bike-front-light

I really don't need it as I have a good solution already.

I have just dug out my RFR lights and thought about giving them another try, and remembered that lack of switch was one of the things that put me off.  I could solder in a switch but it is extra hassle and creates an extra point of potential failure.  I did get some inline USB switches (a bit of USB extension cable with a switch in the middle) but they were bulky, and really need to go inside a bag for waterproofness.

I've got the RFR 50 lux one on to see what time I get from a power bank, to compare against others.  ISTR it didn't last as long as I'd hoped (other reason why I dropped it).  I've got bigger power banks now than three years ago when I last looked at it so it might make sense to do it.  Or I could just buy the Supernova... or get an  8.4V pack...

[Kim]

A couple of years ago I looked into using e-bike lights with power banks.  It would be for long distance events so I wanted to standardise batteries for interchangeability and minimise charging kit.

Most e-bike lights don't work at 5V (I tested a B+M and it doesn't) but some do.  I got a couple of fairly cheap RFR ones (50 and 90 lux) but the beam pattern isn't as good as B+M so I haven't really used them.  I then found something else which worked well, so didn't add to my e-bike light collection.  However, the other ones that work at 5V are Supernova, which are meant to be good but very expensive. 

Alternative approach: Power bank that supports QC or PD, and a cable with the gubbins that requests a higher voltage:
 https://www.ebay.co.uk/itm/144445097706

(I've got one of these with a USB-A plug on it that I use with my portable soldering iron.)

You can also get USB cables with a boost converter inline.  Probably not as efficient, but would work with any power bank.

[Frank9755]

Alternative approach: Power bank that supports QC or PD, and a cable with the gubbins that requests a higher voltage:
 https://www.ebay.co.uk/itm/144445097706

Interesting, thanks.
I expect my new power banks would work with this so it is tempting!

[quixoticgeek]

There's something addictive (to me at least) about finding something that was designed for a slightly different purpose and tweaking it to make it work better than the normal options for a related purpose.  I wish I could get help for it!

This is the one that I would like to buy:
https://winstanleysbikes.co.uk/supernova-m99-mini-pro-25-e-bike-front-light

I have one of these in my box of parts. It's a lovely light. I got it when I was having a crisis of confidence about dynamos. If I could find a way to mount it along side my Edelux II, I would carry it as the backup light on the TCR.

J

[damitamit]

There's something addictive (to me at least) about finding something that was designed for a slightly different purpose and tweaking it to make it work better than the normal options for a related purpose.  I wish I could get help for it!

This! I always feel like there must be better/cheaper option out there. It's super satisfying when it works out.

[Lightning Phil]

Interesting.  What’s the weight of the battery pack?

127g empty.
314g with 4 3000mah Sofirn 18650s.

I notice Magicshine now have a 10,000mAh light with USB-C fast charge port.  Looking at about 400g including the head unit then.

[aidan.f]

Anyone tried two 5Vole power banks in series for 10 Voles?

[Frank9755]

No, nor would I.  I'd be worried about fucking something up and it would be too risky in the situations in which I would use them.  Also I don't carry evenly matched pairs and I do want 5V for some things: phone, GPS, etc

Kim's magic wires ^^^ seem a much better option

[lissotriton]

Picked up a Lumintop B01 flashlight on aliexpress which takes a 21700 cell and has a "designed according to STVZO" beam. Yet to try it on the road but it has a 11 hour medium 260 lumen mode which could work well.

That looks like a neat little thing. I'd rather have an all in one light, instead of wires to a separate battery pack. And USB-C charging built in is handy.
Wondering if it is any good. The mount looks a bit flimsy, does it hold it in place securely?
It is a bit cheaper than the equivalent Fenix bike lights anyway.

[damitamit]

Picked up a Lumintop B01 flashlight on aliexpress which takes a 21700 cell and has a "designed according to STVZO" beam. Yet to try it on the road but it has a 11 hour medium 260 lumen mode which could work well.

That looks like a neat little thing. I'd rather have an all in one light, instead of wires to a separate battery pack. And USB-C charging built in is handy.
Wondering if it is any good. The mount looks a bit flimsy, does it hold it in place securely?
It is a bit cheaper than the equivalent Fenix bike lights anyway.

Haven't been for a ride with it yet but hoping it is good as it seems the easiest option (with x number of spare 21700 cells). Hoping to try it out tonight.

It's got a downward pointing emitter and a reflector so hopefully the beam pattern is good.


The mount is actually really secure but a bit bulky. So I've ordered one of these to mount it under my garmin mount. https://76projects.com/collections/shop-computer-mounts-light-brackets/products/gopro-style-light-brackets

[sojournermike]

All of my 4x18650 boxes have a ‘raw’ output (protected) and a 5V regulated output up to 2 amps. So they function as both a light power source and a usb power bank if needed.

Mike

[damitamit]

Update on this. After using the Lumintop B01 flashlight a couple of times and on a 600 in june, I decided this would be less hassle then the ebike light + battery pack.

Used it on LEL and it was perfect. Good enough beam on medium mode (supposedly 11 hours) and ability to switch to high easily for faster bits. Worked great on all the big descents in the pennines. Used 3 5000mah cells over the course of LEL (took 5 in total). Also took a spare B01 as they're so light/cheap. The included mount also worked flawlessly.

My riding partner also bought one and his first use of it was on LEL. He was impressed.

In summary, it makes a great audax light. Unlimited battery life based on how many cells you bring and you can even power it with a usb-c powerbank.

[Frank9755]

Thanks for the update.  Based on that I've ordered one.

I broke my light on TCR.  I lost control of the bike taking it down a ramp by some steps coming out of a hotel and fell on top of it, kicking my light, which seemed to bugger the connection so it kept cutting out.  It was only for the last couple of days but I could have done with a better back up option.