Lead acid battery for bike lights help?

[gidon]

I have two sets of 6v cycle lights that run off lead acid batteries. I have tried both batteries (one is newer than the other) and after an overnight charge they are not working. This is the battery and connector:

I have measured the battery at the terminals and it measures 6v. And at the connector bit to the lights it also measures 6v. The bulbs aren't gone (I've checked the resistance across the terminal on the lights connector).

Has anyone got any ideas or know where I can get the battery connector (think maplin do the batteries) if that's the only option. The lights weren't cheap.

Thanks a lot

Gidon

 

[RobertMP]

Unlikely to be the 1/4" spade connectors on the battery terminals. Most likely thing is a bit of corrosion on a plug connector or the fuse or something. You may be able to see a circuit with a meter but the corrosion stops any real current flowing. Just check and clean every connection with a dry kitchen scourer or fine wet and dry. if there has been damp inside a connector for a while then the wire itself could be corroded where it is crimped.

 

[OLD]

I agree with robertmp high resistance is the problem this could be the fuse the wire connections or the bulb connections or the main connector may not be making a connection stick with it you will find it soon.

 

[gidon]

Thanks both of you. Thing is they are both in very good condition as you can see from pic and I can't see any corrosion at all on any of the connectors ...
Cheers
Gidon

 

[MickCheese]

Try just connecting the bulb to the battery with the two wires in the pic.

If the bulb does not light you know it is the bulb.

The only other area for investigation is the switch, have you given that a spray of WD40?

I don't know a lot about cycles but have hate electrical problems with my motorbikes.

Mick

 

[Racers]

Hi,

Undo that fuse and check the ends on the fuse holder aren't dirty, scrape them clean if they are and try again.


Pete

 

[ike]

Is it for Cateye Double Daylights? If so its a 2.5mm socket you need. Maplins should have them. I found the plug lead works loose occasionally. Try giving it a wiggle anyway.

cheers,

ike

 

[gidon]

Thanks chaps.
Mick - the bulbs are ok - have checked them with the multimeter plus they light up very slightly occasionally.
Pete will check the fuse but looks clean.
Ike - no Smart Halogens. You can see the connector in this pic:

Cheers

Gidon

 

[Racers]

Hi, Gidon

I recon you have a bad/dirty contact some where, try cleaning/ tightening every connection/joint.

Pete

 

[andycktm]

Gidon, you sure the batteries are ok? Shouldn't they read nearer 6.6v ?

 

[CHJ]

Hi, Gidon, what's the battery voltage reading with everthing connected and lights switched on.

Batteries may not be charged or sulphated up.

If these batteries are just left on the shelf without a regular charge discharge cyle every month or so, say over the summer months when not in use they can self destruct.

 

[RobertMP]

Being me I'd check the battery was capable of giving power by using a bit of heavy wire to see how big a spark I got shorting the terminals *very* briefly. Hold the wire on one terminal and then flick the other end across the other terminal so it brushes it in passing. healthy welding type spark and its OK. Wimpy crackle and its not got much go in it. Not suggesting you try it though

The wire would burn out like a giant fuse if left connected across the terminals so don't try that.

 

[Ironballs]

I thought that looked like a Smart battery box, I had one and had the same problem you did, the solution? Bin it, couldn't get it to work. Then you realise that it weighs a ton, doesn't run for very long and has the light output of a big candle.

Most of the cheap LED lights from Halfords will outperform that thing and for a slightly bigger outlay you can get a decent light that will chuck out a fair amount of lumens. You could even go the whole hog and spend a couple of hundred quid on a HID lamp like what I have - essential for biking offroad at night.

Certainly these days there's no reason to run lead acid, NiMh and Li ion are both lighter, cheap, more powerful, have longer run times, shorter charge times etc

 

[gidon]

Thanks for all the help.
I've tried various things and think both batteries are shot. Although the batteries measure 6V'ish when connected to lights they measure less than 1/2 a volt!
Bit nervous to try a spark test. I may try and get another battery if I see one cheap. Someone did mention that you can kick the batteries back into action with some sort of shorting but don't want to try that either!
Ironballs - I found the lights pretty good - bright enough to light a a dark road (not good enough for off road) - the weight's nothing compared to weight of bike! But they are old now so I'm sure much better around now.
Cheers
Gidon

 

[Racers]

Hi, Gidon

http://www.maplin.co.uk/Module.aspx?ModuleNo=19363
Yuasa NP4-6 Maplins code L21AC £9.99


Pete

 

[gidon]

Thanks a lot Pete - not sure if silly question but they also list rechargeable lead acid batteries seperately - which is what I currently have is? Aren't they all? Good thing with Maplin is could probably try it and if doesn't work take it back .
The dimensions are spot on though - only other difference is 4.5Ah vs 4Ah which is only good I suppose?
Cheers
Gidon

 

[Racers]

Hi Gidon

All lead acids are rechargeable, its just a Maplins website foible don’t worry about it.


Pete

 

[gidon]

Thanks Pete! Though I'd check before make journey into Plymouth.
Cheers
Gidon

 

[Digit]

Check the charger as well.

Roy.

 

[Ironballs]

Bin it....................

Go for something like this

http://www.halfords.com/webapp/wcs/stor ... yId_165636

That Smart will run for about 2 hours max before needing a charge, this one runs for 80 hours