Energizer Universal Battery Charger repair

Groan, the dishwasher is broken again. Out with the multimeter.
Groan, the multimeter's rechargeable battery is flat. To the battery charger.
Groan, also not working.

Sometimes you end more steps back than forward.

Q. How do you sort out what is wrong with your battery charger when the battery in your multimeter has gone flat?
A. Buy a spare alkaline battery.

Well off to see Mr. Tesco for a quick fix,

Multimeter back into operation

Now the multimeter is working, but the battery charger (and dishwasher) are still broken.

First things first, is the charger getting juice from the power supply unit (PSU)? It should be outputting 12 V DC, but is actually supplying 0 V. Culprit identified.

After popping the cover off the PSU and giving it the once over there are no obvious shorts or burnt out components. So no easy fix for this.

Battery charger PSU internals

The part # for the Energizer Switching Mode Power Supply is CHEUF-ADP-UK. I don't have any experience with switched mode power supplies, but apparently they are popular as they are small, lightweight (in terms of transformer size) and power efficient. The circuitry in the Battery Charger PSU includes a mix of discrete through hole and surface mount components. As I am not sure how the circuit is laid out or which of the components is faulty, troubleshooting is not likely to be a quick or painless option. So time to think of some other routes to getting the charger functional again.

The first option is to replace the PSU in its entirety, not very green I grant you but better than chucking the whole charger and replacing (you would think).

But not if you want an Energizer PSU. For a start Energizer don't sell them,

Thanks for contacting ENERGIZER.
Unfortunately, we do not sell spare parts.

We remain at your disposal,
Thanks
Kind regards

Energizer consumer service

which is not the epitome of responsible corporate stewardship. Or in their words "we believe everyone has the power to make a positive impact", aka " we believe everyone can buy into our corporate greenwashing, while we can't be bothered to ship out replacement PSUs even though it would be a stupidly easy thing to do, just throw your charger in the bin and buy a new one like a good consumer, screw the planet. " At least they ponied up the information quickly though.

The on-line sources were not attractive [Amazon - unavailable, eBay (used) - £12.95, on-line search - £17.00], which are almost as much as buying a brand-new charger [£17 vs £20], which on point of principle I am now refusing to do.

The next option is to buy an OEM wall wart with the same rating, much more reasonable at £3.88 arriving on a slow boat from China. A cynic would note how it looks almost identical to the Energzier one. However it is still remotely possible that I could fix the original unit which would then leave me with two. Not that that would be a major issue.

OEM charger PSU

Thinking about using an OEM PSU lead me to realise I hadn't been through the parts bin. Happily a search through the bin yielded a PSU from a long since deceased scanner which is 12 V/1.0 A rated. A bit higher than the 12 V/0.6 A of the original charger but available immediately at £0.00.

Sounds OK, but the DC power plugs are not the same, grr. Both are 5.5 mm OD, but the spare is 2.1 mm rather than 2.5 mm ID so won't fit the charger.

Different internal bores of DC power plugs

Back on-line for more searching to find a DC power adaptor for £1 off eBay.

Battery Charger fix complete

…

Wait a month for the slow boat from China to arrive.

…

Unpack and plug in replacement charger. No issues, but won't leave on unattended for a while just in case.

JOB DONE

Time taken : 5min to put in new plug, 2 hr to work out what was needed, 30 days to receive part.
Cost : £0.99