Search my site

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

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You’ll also probably also know that the Draper 6V ARHL battery pack is obsolete and nobody’s got any spares.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....

If anyone's interested, here's a photo of the innards of the trickle-charger block.  There seem to be some variations between different units.

Draper RHL185 charger [click to see]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.

A recommended Eagle-brand mains adaptor is shown below, offering 9V (and more) at up to an amp if you need a new mains adaptor. I've suggested a car cigar-lighter adaptor that should work as well (untried).


Reader Comments (9)

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.

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

I have a Draper RHL185, and the blue charging adapter that fits on top of the battery housing. However I'm not sure I have the correct draper charger. I assume not as it a 9 volt charger, however the DC plug fits fine… But the charger plug starting getting too hot.

Could you advise me what the charging voltage should be please? I'm not sure what the blue adaptor dose but I did notice a small circuit board inside.

Also do you have any idea if there was a car charger?

Many thanks in advance and furthermore for this article.

November 4, 2017 at 10:33 | Unregistered CommenterBrian

The Draper battery is a 6V lead-acid type, but the blue charger block that you place over the battery, is powered from a common 9 Volt mains adaptor.

The small circuit board is very basic. It contains a resistor to drop the 9V voltage and limit the charging current, plus a rectifier to protect against reverse connection. The green l.e.d. always glows when it's charging from the adaptor. The battery's increasing voltage gradually 'shunts' the red l.e.d. until it stops glowing.

Due to the mechanics, it's the only way of charging the Draper battery. I looked at hacking around the lamp itself, so that I could charge the battery in situ, but I don't think it would work very well.

You could use any 9V d.c. mains adaptor, 450mA or higher, that matches the socket (and indeed I use a better quality one taken from something else). The connector centre pin is almost always positive.

I believe Draper did include a 12V cigar lighter plug with a lead that connects into the blue block instead of using the mains adaptor. It too will drop the voltage to the necessary 9V or so needed by the blue block.

On this webpage I have added suggestions for a decent mains adaptor and a car cigar lighter charger that ought to do the trick if you've lost the originals.

November 4, 2017 at 11:28 | Registered CommenterAlan W

Many thanks for that - must be the easiest battery swap going. I could do without yet another fiddly job of soldering and packing NiCd cells into impossible spaces!

May 5, 2018 at 7:45 | Unregistered CommenterAndy

I got my my fathers torch when he passed away. Unfortunately there was no charger and the battery was flat. I have been trying for several years to get advice and help without success. I then saw the way to do it above. I am unable and getting too old to do these alterations above. If someone lives near by and could do it for me, I would be happy to pay for the help. I live in Bushey, Hertfordshire. Please contact me [via this web site - I will pass it on - AW] if you could help. I could bring the torch to you. Thanks.
Alan Martin

July 5, 2018 at 20:28 | Unregistered CommenterAlan Martin

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):
Some HTML allowed: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <code> <em> <i> <strike> <strong>