bike lights Bicycle light batteries - My pet project

[DieselnDust]

Brings back memories of the first Wiesenhof 24 hr at the end of 2003 where a rider was seen descending from the snake climb with a battery on fire. Riders reported a lot of screaming, toxic fumes and eventually a lot of sand shovelling. Shorting out a SLA battery wasn't uncommon and was incredibly funny. Back then the grade of PVC tubing and whether an OSRAM halogen was better than a PnP halogen populated the "What light debates" on emailing mailing groups

[Hairy]

Brings back memories of the first Wiesenhof 24 hr at the end of 2003 where a rider was seen descending from the snake climb with a battery on fire. Riders reported a lot of screaming, toxic fumes and eventually a lot of sand shovelling. Shorting out a SLA battery wasn't uncommon and was incredibly funny. Back then the grade of PVC tubing and whether an OSRAM halogen was better than a PnP halogen populated the "What light debates" on emailing mailing groups

LOL... I had a DIY headlamp where the one fixing screw cut through the wiring in the PVC housing and whilst standing in the parking lot a lady said to me your headlamp is smoking .. all poops and giggles.

[Lamber]

How do you balance the charging of the cells?  I know that is the number one killer of notebook batteries.

 

I bought a load balancing charger (they use it to charge cells for RC cars) that we rigged to charge a light (LED) that my wife drop tested and broke.  So we replaced the batteries with old notebook batteries that are still useable and changed a few things to load balance the batteries.

 

I once started working on building a battery pack and got the load circuit to charge 6 batteries at a time, but I know you do get bigger load balancers.

 

PCM with equilibrium function normally comes into play for a pack of >5 cells or >18.5V (as a rule of thumb). These systems are usually stationary and does not have to conform to the vibration and size limitations that bicycle batteries call for.

[droo]

I've got drawings somewhere for a light head, so if you manage to sort out a reasonable power solution, PM me if you're keen to build something. 

[Lamber]

Just a short update - currently sitting at 52 hours and things are still looking bright. 

 

On the down side if the battery lasts another day I probably need to move the setup to my garage - SOH is not too pleased about this experiment being conducted in the bedroom 

[Lamber]

I've got drawings somewhere for a light head, so if you manage to sort out a reasonable power solution, PM me if you're keen to build something. 

Thanks for getting in touch - will definitely keep it in mind!

Edited April 7, 2021 by Lamber

[Lamber]

my only 2c- a few years back we could buy bike light batteries that were built in a bottle shape. They were massive batteries. But it was nice to have a single battery unit that you could mount in a bottle cage and be done for a whole expedition race...

How long (how many nights) would an expedition race like this typically last?

[Lamber]

Another update - at 10:00 today the stopwatch will read 92 hours of battery life thus far. I hope at 14:00 this afternoon I can hit the 4 day (96 hours) mark, however the indicator light has flipped to orange earlier this morning so I doubt it. 

[Lamber]

Some general information on 18650 cells which I thought I'd share. This might be common knowledge to most but it could save you some research time if you haven't gone down the rabbit hole yet.

 

18650 cells shot to popularity when they were used in the first Tesla vehicles and Powerwalls. Since then there has been two upgrades on the size of the Tesla cells but the 18650s remain popular for mostly small consumers (vaping, torches, small battery packs etc). They are called 18650s because the are 18mm in diameter and 65mm long.

 

As with most popular tech, an abundance of cheap fakes flooded market to claim insane amounts of storage capacities. I have seen red "Ultrafire" cells (pic below) claiming anything up to 10 000mAh battery for R15 to R50 a piece. Luckily they are easy to spot:

 

1. Price - expect to pay between R100 and R200 per cell when buying retail depending on the chemistry and capacity of the battery

 

2. Mass - I use 42grams as a rule of thumb, if it weighs less than that it is most probably useless

 

3. Graphics - this is tricky as some suppliers rebrand cells for retail, so here my rule is the more graphics the less likely I am to buy it - graphics cost money which means either someone is putting a 100% markup on a cell or the are trying hard to sell a poor quality battery. Graphics also conceal important data (such as manufacturer, chemistry and capacity) which forms the basis of the informed buyer.

 

4. Manufacturers - Sanyo, Samsung, LG and Panasonic are brands that you can bet on. Their branding won't be flashy, rather basic like the purple cell pictured below.

 

5. Data data data. If a supplier has a data sheet - you are already on the right track. If they give the mass as per point 2 above then it is 95% legit. You can weigh to confirm and return if it is incorrect - but generally this seldom happens.

 

Lastly and very important - Chemistry.

 

Generally fake cells won't display chemistry so this is only used to differentiate between a good cell and a great cell.

 

IMR: I = Lithium, M =Manganese, R = Rechargeable; Chemical structure = LiMn2O4

 

Sony are the leaders with IMR. They are popular because they can deliver very high currents although only for short time spans.

 

ICR: I = Lithium, C = Cobalt, R = Rechargeable; Chemical structure = LiCoO2

 

Samsung, Sanyo and LG are the leaders here. These cells were the first to become popular with cycle lights but are now the "cheaper option" (although not always marketed/sold as such). They delivery lower currents for longer than the IMR.

 

NCR: N = Nickel, C = Cobalt, R = Rechargeable; Chemical structure = LiNiCoAlO2

 

Again this is the chemistry Tesla uses (I'm not a fanboy, I promise - although I believe they are in the forefront of battery technology because their revenue depend on it. They however call it NCA (Nickel, Cobalt, Aluminium) to highlight the Aluminium component. 

 

NCR is (or should be) the "new normal" as they are high drain batteries for long durations. They are available in 6.8 A and 10 A delivery current versions and most common capacity is 3400mAh. I used Panasonic's NCR in my experimental pack.

 

 

Pic1 - cheap fake 4200mAh: R15, Pic2 Samsung 2600mAh ICR: R110

Edited April 9, 2021 by Lamber

[DieselnDust]

Some general information on 18650 cells which I thought I'd share. This might be common knowledge to most but it could save you some research time if you haven't gone down the rabbit hole yet.

 

18650 cells shot to popularity when they were used in the first Tesla vehicles and Powerwalls. Since then there has been two upgrades on the size of the Tesla cells but the 18650s remain popular for mostly small consumers (vaping, torches, small battery packs etc). They are called 18650s because the are 18mm in diameter and 65mm long.

 

As with most popular tech, an abundance of cheap fakes flooded market to claim insane amounts of storage capacities. I have seen red "Ultrafire" cells (pic below) claiming anything up to 10 000mAh battery for R15 to R50 a piece. Luckily they are easy to spot:

 

1. Price - expect to pay between R100 and R200 per cell when buying retail depending on the chemistry and capacity of the battery

 

2. Mass - I use 42grams as a rule of thumb, if it weighs less than that it is most probably useless

 

3. Graphics - this is tricky as some suppliers rebrand cells for retail, so here my rule is the more graphics the less likely I am to buy it - graphics cost money which means either someone is putting a 100% markup on a cell or the are trying hard to sell a poor quality battery. Graphics also conceal important data (such as manufacturer, chemistry and capacity) which forms the basis of the informed buyer.

 

4. Manufacturers - Sanyo, Samsung, LG and Panasonic are brands that you can bet on. Their branding won't be flashy, rather basic like the purple cell pictured below.

 

5. Data data data. If a supplier has a data sheet - you are already on the right track. If they give the mass as per point 2 above then it is 95% legit. You can weigh to confirm and return if it is incorrect - but generally this seldom happens.

 

Lastly and very important - Chemistry.

 

Generally fake cells won't display chemistry so this is only used to differentiate between a good cell and a great cell.

 

IMR: I = Lithium, M =Manganese, R = Rechargeable; Chemical structure = LiMn2O4

 

Sony are the leaders with IMR. They are popular because they can deliver very high currents although only for short time spans.

 

ICR: I = Lithium, C = Cobalt, R = Rechargeable; Chemical structure = LiCoO2

 

Samsung, Sanyo and LG are the leaders here. These cells were the first to become popular with cycle lights but are now the "cheaper option" (although not always marketed/sold as such). They delivery lower currents for longer than the IMR.

 

NCR: N = Nickel, C = Cobalt, R = Rechargeable; Chemical structure = LiNiCoAlO2

 

Again this is the chemistry Tesla uses (I'm not a fanboy, I promise - although I believe they are in the forefront of battery technology because their revenue depend on it. They however call it NCA (Nickel, Cobalt, Aluminium) to highlight the Aluminium component. 

 

NCR is (or should be) the "new normal" as they are high drain batteries for long durations. They are available in 6.8 A and 10 A delivery current versions and most common capacity is 3400mAh. I used Panasonic's NCR in my experimental pack.

 

 

Pic1 - cheap fake 4200mAh: R15, Pic2 Samsung 2600mAh ICR: R110

 

 

Great post and 110% factual. Make this one a Sticky!

[Zebra]

Another update - at 10:00 today the stopwatch will read 92 hours of battery life thus far. I hope at 14:00 this afternoon I can hit the 4 day (96 hours) mark, however the indicator light has flipped to orange earlier this morning so I doubt it. 

keen to hear your finding, later today/tonite, I guess!

nice and informative post

thanks

Chris

[Stevovo]

I am following with interest. Thanks for the write up.

 

I have also been looking at these cells the past month or so. Extreme lights seems to be using a Panasonic NCR18659B cell that they claim to be protected and you can buy them on their site for R345 per cell. I also found this cells available at https://www.batteryexperts.co.za/shop/panasonic-ncr18650b/ but not a protected version with the same number for R181. They also build bicycle light battery packs on demand. Might try them out.

 

Do you know which cells are in your battery pack?

[Hairy]

This thread is turning into a phenomenal resource!

[Lamber]

I am following with interest. Thanks for the write up.

 

I have also been looking at these cells the past month or so. Extreme lights seems to be using a Panasonic NCR18659B cell that they claim to be protected and you can buy them on their site for R345 per cell. I also found this cells available at https://www.batteryexperts.co.za/shop/panasonic-ncr18650b/ but not a protected version with the same number for R181. They also build bicycle light battery packs on demand. Might try them out.

 

Do you know which cells are in your battery pack?

I am using the exact same NCR18650B cells which a well known SA company is using. 

 

The claim that the single cell is protected is true - you will note that they are 5.5mm longer at 70.5mm and not 65mm as the general 18650s which houses the vents and protection. I have been using unprotected cells since the 2018 TransXhariep and haven't had a days problem in my Ryder Concept 1000. I guess it's always fine until it isn't - that's down to personal opinion & finance.

[Lamber]

And so it is with great sadness that I must announce the loss of the "Alpha Battery's" (yes I gave it a name  ) first of an estimated 1000 lives.

 

200 Lumens = 97 Hours 41 Minutes 39 Seconds

 

Obviously this was a stationary test done at 24 - 29 degrees Celsius (baby monitors don't lie - apparently) and I will continue improving my testing parameters with the assistance & input from all on this thread. Thanks for the questions and comments - it has helped tremendously.

 

Over the weekend I will try to do stationary tests on both the higher lumen settings if time allows and post results next week. If I end up boring everyone at least I have documented my nonsense for future use. I believe the more understanding you have of your gear, the more confidence you have when taking on the challenging rides/race. 

 

Have a great weekend

Edited April 9, 2021 by Lamber

[Hairy]

And so it is with great sadness that I must announce the loss of the "Alpha Battery's" (yes I gave it a name  ) first of an estimated 1000 lives.

 

200 Lumens = 97 Hours 41 Minutes 39 Seconds

 

Obviously this was a stationary test done at 24 - 29 degrees Celsius (baby monitors don't lie - apparently) and I will continue improving my testing parameters with the assistance & input from all on this thread. Thanks for the questions and comments - it has helped tremendously.

 

Over the weekend I will try to do stationary tests on both the higher lumen settings if time allows and post results next week. If I end up boring everyone at least I have documented my nonsense for future use. I believe the more understanding you have of your gear, the more confidence you have when taking on the challenging rides/race. 

 

Have a great weekend

What is the recharge time on the battery pack?