UK 400R/D4R battery pack

[Nick Pope]

My UK 400R NiCd battery pack is failing (again) and I'm thinking that it can't be too difficult to disassemble the dead pack, salvage the charging connector and contact plate, and rebuild the pack with new NiCd cells rather than lash out loads on a complete new pack.

Has anyone done this before?

Just thought I'd ask before I set to with the stanley knife :D

cheers

Nick

[PeteM]

My UK 400R NiCd battery pack is failing (again) and I'm thinking that it can't be too difficult to disassemble the dead pack, salvage the charging connector and contact plate, and rebuild the pack with new NiCd cells rather than lash out loads on a complete new pack.

Has anyone done this before?

Just thought I'd ask before I set to with the stanley knife :D

cheers

Nick

Not personally but I've seen it done and you are right it is trivial providing you can use a soldering iron. I would use gaffer tape rather than heat shrink to put it back together though.

[ChristianG]

My UK 400R NiCd battery pack is failing (again) and I'm thinking that it can't be too difficult to disassemble the dead pack, salvage the charging connector and contact plate, and rebuild the pack with new NiCd cells rather than lash out loads on a complete new pack.

Has anyone done this before?
It's been done many a time and oft, in my case regularly with the battery pack of the Nikonos SB-104 strobes I used to own. Nikon wanted us to replace it with a ludicrously expensive new one but someone (not me) pulled the wretched thing apart and advised everyone how to replace the (IIRC) D Cell batteries.

I have no idea of what your one looks like but in our case it meant the use of a very fine saw, I "employed" my dentist for this, to cut the "head" off the battery pack, after which it was easy to replace the batteries and glue it back together with "superglue". After that it became easier because the superglue "spot welds" could be cut much more easily. I think I did it four times with no issues at all. In my/our case the major initial issue was not to cut too deeply.

[TrevorB]

Nick

If the battery pack is dead then you have nothing to loose. Ni-cd are not very nice batteries and can often get reverse polarity problems, because of the series charging arrangement. If you have a volt meter check the individual cells for reverse polarity they might not all be faulty. I have never had a problem with my diving torch, but I have rebuilt numerious battery belts for filming, and its a simular problem. One thing to remember with Ni-cd always exaust before charging and never over charge ie charge just for the specified time. I know its not easy but anything else will shorten their life. You are welcome to borrow my soldering iron any time, sorry I am not local

[bluewater]

My UK 400R NiCd battery pack is failing (again) and I'm thinking that it can't be too difficult to disassemble the dead pack, salvage the charging connector and contact plate, and rebuild the pack with new NiCd cells rather than lash out loads on a complete new pack.

Has anyone done this before?

Just thought I'd ask before I set to with the stanley knife :D

cheers

Nick

Yes done it with the same torch. and easy to salvage the top, bottom and socket. Replace all 4 batteries whilst your at it and be sure to get batteries with solder lugs on makes it really easy.

[TerryH]

Here's a tip.

If you work in a big office with emergency lighting, guess what batteries they
use ;)

And as it's emergency they have to change them well before they are
knackered, which means .....................

[Nick Pope]

Thanks folks for all the replies. I guessed someone had done it before, which is why I asked.

I'm just testing the battery pack to see how long it holds a charge. It seems fine if you take it off charge in the morning and go diving in the evening, but if for example I take it off charge on Weds and don't dive till Sat, it lasts about 10 mins.
The current pack has probably been through 300-400 charge/discharge cycles, so probably past its best.

Will look for solder tagged batteries via Farnell or Maplins.
cheers

Nick

[ChristianG]

Nick,

Rather than NiCads you should be able to get NiMhs, even LiIons at the same mAh and voltage. Both are streets better than NiCad and (theoretically anyway - I have some doubts about the NiMhs in that regard) eliminate the overcharging/reverse polarity issue.

You may also want to invest in what is called an "intelligent charger". Ansmann (http://www.ansmann.de/cms/consumroot.html) make some seriously good chargers and batteries for that matter. Here's the UK site (http://www.applegate.co.uk/electronics/battery-charger-0042384.htm). I've used Ansmann stuff (in preference to any other) for years now.

[Nick Pope]

Hi Christian,
I thought about alternative cells, but TBH NiCd cells are less than £2 each for slightly higher mAH than originals, straight swap, same charger. If they'll do me another 300 - 400 dives before I change them again, thats fine :D

Nick

[pacland]

Hi Nick,

Would you mind sharing your source for your cells?

I have a D8R with the same problem.

Spoke to Strikalite regarding prices for a pack of NiMH cells, £80.65 not including postage (~£8 iirc).
They advertise the NiCd on their site for £60.

Not sure about the mAh though.

[Nick Pope]

Maplin.
Sorry, my old catalogue was well out of date regarding price.
Website shows solder tagged 2800mAh C-cell NiCd @ £4.99 ea (p/n VN44X).

Still cheaper than the genuine pack :)

Nick

[Nick Pope]

Just thought I'd post an update.
I stripped the old battery pack and rebuilt it using solder-tagged D-cell Nicads from RS components.
On the old cells the solder tags were long enough to solder cell to cell, but on the replacements the tags were shorter and required a short length of wire to join each cell.
I also upgraded the cells from the 2800mAH originals to 5000mAH cells giving considerably longer burn time.

I also have an even older UK400 - the non rechargeable type. I also purchased some non-tagged Nicad D-cells to fit this (4400mAH) and replaced the bulb, effectively making it into a UK400R rechargeable.

So, for a total cost of about £70 and a few hours work I have two good-as-new torches :D

Nick

[ChristianG]

So, for a total cost of about £70 and a few hours work I have two good-as-new torches
You've done well, it's also well worth knowing that the so-called arcane methods of the "battery pack people" can be circumvented relatively easily by other people with a modicum of common sense. :D
It seriously gets up my nose when people (Nikon in my case) tell me that I have to replace the whole battery pack at some ridiculous expense when replacing just the batteries themselves is definitely an option.

[phumb]

sounds like i'm not alone..someone has given me 2 of these rechargeable lights...only one battery pack, and no charger...I will be making my own nicad battery pac...could someone please tell me the output power (volts and amps) on the charger that came with this and also the recommended charging time? THANKS!

[TrevorB]

NiCad’s are a constant current charge, voltage is not important

use 1/10 of the ampere hours and charge for 10 hours
i.e. if 1 ampere hour charge at 100 mA for 10 hours

I am sure there will be a circuit on the net if not I will design you one

[phumb]

thanks trevor!

[TrevorB]

just checked up is 16 hours at 10% of capacity

Just to be sure I open up my torch and yes
its 4.4amp capacity and charge at 440mA for 14 to 16 hours

lots of chargers on ebay

[phumb]

gotcha, I have a 500ma...sure thats good correct? even though 12v?

[TrevorB]

Don’t worry about voltage it’s all about current, the charger will vary the voltage to get the correct current unless it runs out of steam

Capacity /10 for the current
charge for 16 hours

I assume they are 5 amp/hour batteries

If you charge quicker they may overheat and rupture

if you have multi meter put it on current and in series with the charger and check for 500mA

[Aquamarina]

Sorry to join in, but on the subject of D4R batteries, I've noticed that mine has two really small holes at the top of the pack, where it connects to the bulbs. This means that the torch works, then doesn't, then works! Rather than buy a new battery (because the battery is clearly ok), is there anything I can do to fill the holes, like add solder, to fix the problem?? Ideas on a postcard... Thanks.