Brightest possible front light

[103Alex1]

Heres one

Very good m'lady .... but I think this one might be more comfortable with the drive required :

 

[103Alex1]

A new contender :

 

[103Alex1]

Beware of cell imbalance with these lights if they come with battery packs, all three of mine had simple LVC circuits but no facility to balance cells so I ended up adding balance leads to all three packs. Two of them showed badly balanced cells which meant shorter than expected illumination time

How do you go about making a balance lead for these 4-cell packs ?

 

[Deleted member 4366]

Lipo Balance Extension Charger Cable Lead 2s JST-XH 220mm | eBay
Tiger Wing 1.5A B3 LCD LiPo 2s 3S Balancer Charger 7.4v 11.1V RC Battery B6 IMAX | eBay

 

[averhamdave]

Lipo Balance Extension Charger Cable Lead 2s JST-XH 220mm | eBay
Tiger Wing 1.5A B3 LCD LiPo 2s 3S Balancer Charger 7.4v 11.1V RC Battery B6 IMAX | eBay

For a 4 cell pack you'll need something that will balance 4 cells. Probably best to get a 6 cell balance charger from Turnigy.

The one you have highlighted d8veh really is rubbish. I sell RC parts and had a batch of these in from China and finished up throwing most of them away. I test all Chinese electrical stuff before I sell it and was horrified how many of them either didn't stop charging, discharged rather than charged or charged one cell and not the others!

 

[averhamdave]

I have no connection with the seller but this is the best "cheap" lipo/life/nimh balance charger going. Same layout as the IMax B6 but this has a cooling fan built in.

Turnigy Accucel 6 50W 6A LiPo NiMh NiCd LiFe Balancer Charger w/ accessories | eBay

 

[103Alex1]

I have no connection with the seller but this is the best "cheap" lipo/life/nimh balance charger going. Same layout as the IMax B6 but this has a cooling fan built in.

Turnigy Accucel 6 50W 6A LiPo NiMh NiCd LiFe Balancer Charger w/ accessories | eBay

It's a front bike light though ... and needing a £30 charger to get a bit more run time out of a £9 battery pack is one of those things which just doesn't make much sense. May as well accept the 'out of balance', buy 2 battery packs and carry a spare along in your rack bag.

On Sale! 8.4V Li-ion 4*18650 10000mAh Rechargeable Battery Pack | eBay

I've had more luck with the T6 bike lights themselves than the cheap torches though ... bought one of these and it lasted about an hour before becoming defunkt :

UK1800 Lumen Zoomable CREE XM L T6 LED 18650 Flashlight Torch Zoom Lamp Light GD | eBay

It was meant to be my emergency light for if the Trek built-in system failed for any reason but looks like it wasn't going to be much good as a back-up anyway ! So now I have over £10 worth of high quality 18650 batteries from torchy, a £6 charger (which I just blew up - my fault !) and bike mount but with no working torch to use them with lol. If I thought the £60-£200 UK-sold genuine were any more likely to last more than a few months or a year at best I might consider them - but truth is they are probably not.

 

[Deleted member 4366]

If you've still got your flashlight, take the bottom cap off and look inside (the cap). There's a disk with two small holes in it. The holes are to screw it down, so turn them clockwise with something pointy to see if it sprinfs back to life. Also, the cheap single cells don't have any protection, so if you run them right down, they're knackered.

Cwah has some of those 2/3 cell chargers, and I don't remember him reporting any problems.

 

[103Alex1]

I've given it a go but the torch is completely dead. The single cells I have are 18650 3.7V 2400mAh ones (Yezl from torchy) :

2x Yezl 2400mAh top quality 18650 3.7v protected +case | eBay

They are without memory effect and with digital re/Discharging protection circuit built in. They are measuring 4.22V on multimeter so I don't think it's a problem with the batteries.

The Tiger Wing balancing charger looks to be good only for 2-3 cell packs ?

 

[103Alex1]

Lipo Balance Extension Charger Cable Lead 2s JST-XH 220mm | eBay
Tiger Wing 1.5A B3 LCD LiPo 2s 3S Balancer Charger 7.4v 11.1V RC Battery B6 IMAX | eBay

So with that balance extension charger lead, how does it wire in to the battery circuit on the 4-way pack ?

At the moment, both charging and power draw go via the single 22AWG wire that has the 'magicshine' connector on the end which is in turn soldered onto the P+ / P- contacts on the battery pack PCB.

 

[Deleted member 4366]

The middle wire should be soldered to the strip on the end shown in the first photo.The other two should be soldered to those strips at the other end that go that go to the pcb. If you go for it, I'll give you a detailed sketch.

 

[103Alex1]

The middle wire should be soldered to the strip on the end shown in the first photo.The other two should be soldered to those strips at the other end that go that go to the pcb. If you go for it, I'll give you a detailed sketch.

Thanks ... I might go for it, basically as a building block (baby step !) towards starting to understand LiPos (maybe ...). Got a feeling this parallel / string thing will only start to make sense once I work on something. But I do need to track down an affordable balance charger that'll deal with 4 cells rather than 2-3.

 

[Deleted member 4366]

Does this help?

 

[103Alex1]

I'm working on it but at the moment, no it's all Chinese to me .... mainly I think because I can't understand why the pack is wired up like it is to begin with .

1) The PCB is confusing me because it's a 'black hole' at the moment

2) Don't understand why the strips bridging the cells of separate battery pairs are bridged to each other on one side only of the battery pack

3) Can't understand how there is one wire going to both charge battery and carry current to light when my eBike battery has separate wires for each function (although granted I haven't looked inside as would involve 'unbuilding' all the electrics and breaking open the shrinkwrap to see the layout)

Working through the above from 1st principles will probably help me understand the schematic.