Search my site

Amazon AStore

A selection of relevant products available direct from Amazon. You'll find lots more practical info in various articles on my website.

Visit My Amazon AStore

 

Key Web Links
« How to store a spare car battery at home? | Main | CTEK Battery Chargers connect with 'comfort' »
Thursday
May222014

Repair a Draper ARHL 6V rechargeable battery

Draper RHL185 6V halogen searchlightIf you own an older Draper-brand 6V RHL185 rechargeable lamp then the battery pack is probably showing its age or it might have failed altogether by now. You probably appreciate the lamp’s super-large searchlight but after so many years the battery is probably on its last legs if it won’t charge up very well or the light output on its 6V 55W halogen bulb fades quickly.

You’ll also probably also know that the Draper 6V ARHL battery pack is obsolete and nobody’s got any spares. Some new LED lamps are available such as these LED searchlights on Amazon

It’s possible to replace Ni-cad cells in typical battery packs like these, but the Draper ARHL product label offers us a clue in the form of the wheelie-bin logo – also called the Klein Chemisch Afval (KCA) or Small Chemical Waste symbol that warns us not to send the product to landfill.

The letters ‘Pb’ are shown on the label, which is the chemical symbol for lead so that’s another clue: the Draper ARHL is not a Ni-cad or NiMH battery but a 6V sealed lead-acid battery (SLA) instead, of the type used in ‘One million candlepower’ halogen handlamps etc. of that era.  That’s why the lamp is quite heavy for its size.

 

Note the 'Pb' chemical symbol - it's a lead batterySLA’s wear out after so many charge-discharge cycles, but they can also be damaged if you let them discharge altogether. They should be topped up e.g. monthly or so, and not allowed to run down and they do not over-winter very well. Like many such batteries, if you use them they wear out, and if you don’t use them they still wear out anyway.

How to repair a Draper ARHL rechargeable battery

This task is a doddle and very cheap to do, so don’t throw away the old battery housing but replace the SLA instead. It comes apart with four longer Philips screws and two small ones, to reveal the SLA inside.

Remove 6 x screws (click images to see)The old unlabelled battery, exposed

Unhelpfully, there were no markings or labels on mine, but I soon identified it as a standard 6V 4.0Ah sealed lead-acid battery. This can be replaced with a same-sized one and these are readily available on Amazon (see below).

Slide the wires off the two crimp terminalsSimply slide off the red and black battery crimp leads and hook onto the new one, then tape the wires out of the way a little before sealing it up again. My new battery was almost identical in size but was a very snug fit.

Connect the new battery and tape the wires down as beforeThe housing fits one way round only, and I removed the flat rubber piece in the bottom of the battery housing to help everything fit together better. Note, the polarity is also moulded on the Draper battery housing. The chances are that the new battery is already sufficiently charged, so it's probably not a good idea to over-do things with the Draper charger.

The new battery in placeRe-assembled and ready for charging

The usual strictures apply about not shorting the terminals with a screwdriver, metal watch strap or similar, and the old battery can be disposed of at your local authority rubbish dump recycling centre.

My battery replacement cost £6.00 including postage and hopefully the lamp will be good for a few more years. Remember to top it up at least once or twice a year.

I reverse-engineered the Draper charger and it's nothing special. However it's the only one that slots onto the Draper battery contacts. There is no alternative to using the Draper charger except by adapting the battery pack to accept a 3rd party 6V SLA plug-in charger such as the one listed below. That's another project....

Skytronic offers a plug-in charger for 6V or 12V lead acid batteries,which also has both croc clips and a standard DC connector plug. Another suggestion is the ANSMANN ALCS 2-24A lead acid charger, which automatically detects the battery voltage (2, 6, 12 or 24V) and adjusts accordingly. It has overcharging protection and auto trickle charge. Some users leave it permanently connected to lead acid batteries. It is supplied with croc clip connections only.

 

Reader Comments (5)

I am looking for a charger for my Draper searchlight RHL 185 6V or one that is compatible, any ideas.

June 15, 2014 at 16:33 | Unregistered CommenterTom Sweeney

The problem is that the Draper charger only fits over the Draper battery :(

An electronics nut like me would adapt the Draper battery with a small d.c. socket or terminal block, and build a separate charger that plugs into it directly. I reverse-engineered the Draper battery charger, it's nothing special. A cheap mains adaptor and a small adaptor circuit board are all that's needed.

I looked on ebay for separate 6V SLA (sealed lead acid) battery chargers. This one claims to be suitable for 6V 4Ah batteries.

http://www.ebay.co.uk/itm/300mA-charger-6V-12V-sealed-lead-acid-batteries-/230992147039

You would have to figure a way of connecting it to the Draper battery. Again an electronics hobbyist could adapt it easily, but unfortunately I can see no other way of charging the Draper battery without doing some electronics DIY. I'll work on it.

June 16, 2014 at 13:07 | Unregistered CommenterAW

Brilliant - replaced the "inner" battery exactly as described above, and it works.
Thank you.

March 15, 2016 at 11:47 | Unregistered CommenterPhil S

I also bought battery from ebay and fitted it and it worked as directed in this useful article! I was going to recycle the torch and spent battery at the council tip and now it works again like new! Thanks!

March 10, 2017 at 23:20 | Unregistered CommenterJon Clark

Thank you so much for this article. The lamp was going to get binned recycled but will now have its original battery replaced with a Yuyasa one (same size as the one in your link but better reviews.) and will live on!

April 27, 2017 at 8:21 | Unregistered CommenterNod

PostPost a New Comment

Enter your information below to add a new comment.

My response is on my own website »
Author Email (optional):
Author URL (optional):
Post:
 
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>