Retrobike Forum Index

It is currently Thu Dec 08, 2016 7:31 pm

* Login   * Register * Search  * FAQ



Post new topic Reply to topic  [ 31 posts ]  Go to page Previous  1, 2, 3, 4  Next
Author Message
 Post subject:
PostPosted: Tue Aug 28, 2012 8:40 am 
Gold Trader / PoTM Winner / RB Rider
Gold Trader / PoTM Winner / RB Rider
User avatar

Joined: Wed Oct 05, 2005 7:45 pm
Posts: 10944
Location: kent
JamesM wrote:
3 sets, plus you are going to order some more. You can get a Hope R4 for £170 if you shop around. I have one and they are very nice indeed.


I use them twice a day in the winter .

I think they lasted very well for the money . I will only order batteries .


Top
 Profile  
 
 Post subject:
PostPosted: Tue Aug 28, 2012 9:28 am 
MacRetro rider
MacRetro rider
User avatar

Joined: Fri Mar 09, 2007 2:11 pm
Posts: 8700
Location: DUNDEE
xerxes wrote:
If you open up the battery pack, you'll find inside 4 standard size 3.7v li-ion batteries, something like this:

http://www.ebay.co.uk/sch/i.html?_trksid=p3872.m570.l1313&_nkw=Li-ion+Rechargeable+Battery&_sacat=0

If you're handy with a soldering iron and get hold of some heat shrink tube, you can make you're own battery packs for a fraction of what the bike light people sell them for. You could probably repair the switch and the bit that's rusted as well.



I was under the impression that those batteries need overcharge/shortcircuit protection.
If you make up your own surely you need to source a protection circuit too, which ain't easy to find.
2 of my batteries died due to rain and the short circuit board blew a component both times - batteries themselves are fine but I can't find a new board. Glad it didn't blow the batteries though and a replacement pack with the board is only £12.


Top
 Profile  
 
 Post subject:
PostPosted: Tue Aug 28, 2012 4:28 pm 
Retro Guru
User avatar

Joined: Sun Mar 14, 2010 2:33 am
Posts: 2926
Location: daaan saaaf
Quote:
I was under the impression that those batteries need overcharge/shortcircuit protection.
If you make up your own surely you need to source a protection circuit too, which ain't easy to find.
2 of my batteries died due to rain and the short circuit board blew a component both times - batteries themselves are fine but I can't find a new board. Glad it didn't blow the batteries though and a replacement pack with the board is only £12.


The overcharge/shortcircuit protection will probably in the battery pack and I was thinking that you'd be able to re-use that with the new batteries. However, if that has failed or been damaged, then obviously things are more complicated. :?

When you look at the price of the batteries at around £2 each, you realise that the battery packs at £50 and up are something of a rip-off. I'm fairly certain that the circuit protection board, cable and shrink wrap that constitutes the rest of the battery pack would cost no more than a fiver.

Having said all that, I wonder if there really is any circuit protection in the battery pack itself. It seems that this may actually be built into the battery: http://www.ebay.co.uk/itm/4x-UltraFire-BRC-3-7V-3000mAh-Rechargeable-18650-Li-ion-Batteries-/220919196512?pt=UK_ConsumerElectronics_Batteries_SM&hash=item336fcf6b60

And any overcharge protection will likely be built into the charger.

I wouldn't mind betting that most of the battery packs are simply four 18650 batteries with a suitable cable attached in a heatshrink or waterproof case:

http://www.open-light.co.uk/open-light-4.5ah-magicshine-bikeray-ii-iii-compatible-battery.php?it=271&ca=72&p=1&so=0


Top
 Profile  
 
 Post subject:
PostPosted: Tue Aug 28, 2012 5:21 pm 
MacRetro rider
MacRetro rider
User avatar

Joined: Fri Mar 09, 2007 2:11 pm
Posts: 8700
Location: DUNDEE
The two cheap packs I have had have both had protection boards built in and you would be crazy to omit them, short circuiting a li-ion could end up burning your house/shed down, not worth the risk in my opinion.

You do get them built into individual cells, not sure if you can permanently stack them like that as I would have thought charging would be affected, possibly not though.

in that example you show you can see the wires are connected to the overcharge/short board


Top
 Profile  
 
 Post subject:
PostPosted: Wed Aug 29, 2012 1:14 pm 
Retro Guru
User avatar

Joined: Sat Oct 03, 2009 2:37 pm
Posts: 1728
Location: UK Southwest
xerxes wrote:
When you look at the price of the batteries at around £2 each, you realise that the battery packs at £50 and up are something of a rip-off. I'm fairly certain that the circuit protection board, cable and shrink wrap that constitutes the rest of the battery pack would cost no more than a fiver.

Having said all that, I wonder if there really is any circuit protection in the battery pack itself. It seems that this may actually be built into the battery: http://www.ebay.co.uk/itm/4x-UltraFire-BRC-3-7V-3000mAh-Rechargeable-18650-Li-ion-Batteries-/220919196512?pt=UK_ConsumerElectronics_Batteries_SM&hash=item336fcf6b60

And any overcharge protection will likely be built into the charger.

I wouldn't mind betting that most of the battery packs are simply four 18650 batteries with a suitable cable attached in a heatshrink or waterproof case:



Decent cells cost alot more than £2, but as you said have the protection built in. Its not hard to see why they cost so much money, £50 is cheap for a good 4 cell pack. 4 of these in a waterproof hard plastic case with a good quality connector:

http://www.flashaholics.co.uk/batteries ... -3100.html


Top
 Profile  
 
 Post subject:
PostPosted: Wed Aug 29, 2012 2:04 pm 
Retro Guru
User avatar

Joined: Sun Mar 14, 2010 2:33 am
Posts: 2926
Location: daaan saaaf
Quote:
Decent cells cost alot more than £2


I think it's just an expensive shop, they sell Sanyo Eneloop for about 40% more than they are available elsewhere. :?

There's a lot of marking-up going on with this sort of stuff, much of it is made in the same factories and re-badged. There may be small variances in quality/capacity, but I think you sometimes pay a significant premium for some brands, beyond any real increase in quality.

I think it's a bit of a minefield these days, many brands charge what they can get away with and it's nothing to do with actual cost of production.

Look at this torch: http://www.flashaholics.co.uk/surefire/surefire-e2l-aa-outdoorsman.html.

I'm sure it's very good quality, but £200.00, really? :shock: So, it's more expensive to produce than a television, a washing machine, a bicycle! Is it 15 times better than the similar torch I bought for £15.00, of course not.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Aug 29, 2012 7:56 pm 
Retro Guru
User avatar

Joined: Sat Oct 03, 2009 2:37 pm
Posts: 1728
Location: UK Southwest
Thats alot of money for a torch.

This one is much more reasonable:

http://www.flashaholics.co.uk/eagletac/ ... mark2.html

You can get 8% off if you put CPF in the voucher box at the checkout so it only has to last 3 times longer than yours :lol:

As for the cells, the one I posted a link too was the most expensive highest capacity one on the site. There were others for £12 ish. Maybe that site is a bit steep but I was just trying show that it's only the cheapo direct from china cells that cost £2. Lithium-ion rechargeables can be a dangerous so it's not somewhere you should skimp. You want good cells with protection and a smart charger that will manage the cells during the charging process. Ironic that those cheap batteries are called Ultrafire :lol:


Top
 Profile  
 
 Post subject:
PostPosted: Wed Aug 29, 2012 11:34 pm 
Gold Trader / PoTM Winner / RB Rider
Gold Trader / PoTM Winner / RB Rider
User avatar

Joined: Wed Oct 05, 2005 7:45 pm
Posts: 10944
Location: kent
all the lights you need for £23 :

http://www.ebay.co.uk/itm/230825016348#ht_5783wt_1271


Top
 Profile  
 
 Post subject:
PostPosted: Thu Aug 30, 2012 9:12 am 
Retro Guru
User avatar

Joined: Sat Oct 03, 2009 2:37 pm
Posts: 1728
Location: UK Southwest
For 10 hours :lol:


Top
 Profile  
 
 Post subject:
PostPosted: Thu Aug 30, 2012 6:11 pm 
Gold Trader / MacRetro rider
Gold Trader / MacRetro rider
User avatar

Joined: Sun May 25, 2008 11:03 am
Posts: 18215
Location: Sunny Glasgow
cchris2lou wrote:


1800lm's will keep your head warm too :wink:


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 31 posts ]  Go to page Previous  1, 2, 3, 4  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: 02gf74, ajm, al-onestare, avalonian, Piperdave, SF Klein, videojetman, Woz and 30 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  

About Us

Follow Retrobike

Other cool stuff

All content © 2005-2015 Retrobike unless otherwise stated.
Cookies Policy.
bikedeals - the best bike deals in one place
FatCOGS - Fat Chance Owner's Group

Powered by phpBB® Forum Software © phpBB Group