DAB radio

trog said:
Are you saying that I should only charge 1 battery in each charger at a time?
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As stated above, proper chargers are designed to charge each cell individually. Even very cheap chargers attempt this (but very badly - see https://hummy.tv/forum/threads/interesting-items.3945/page-59#post-111795). Repeatedly charging and discharging a stack of series-connected NiCd or NiMH cells gradually amplifies the slight variations in the capacity of each cell until one fails and takes out the whole stack. So what I was saying is to use a proper charging arrangement and don't just try to recharge the stack by forcing current into it.

trog said:
Also why AAA's in C adapters rather than AA's
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Yes, I am well aware the capacity of an AAA is much less than an AA (much smaller volume to hold the active ingredients), but for the benefit of all those who thought I meant AA: try comparing the size of a C cell with an AA cell, and tell me how an adapter could be made to convert the latter into the former (without access to Tardis technology).*

There remains a question whether 6V is enough. If it was, surely Pure (or whoever) would have made it a four cell battery compartment? It's untidy, but technically I prefer the external 6-cell battery pack.

* This cart shows the dimension specifications for cells: https://www.powerstream.com/Size.htm. AA is 50mm long, C is 46 mm long. Yes, I know Maplin have AA-C adapters, but I assume that is an error and they are actually AAA-C adapters (either that or they hope the extra 4mm can be taken up by the contact spring in the battery compartment - if the cells are actually end-to-end, the combined length error will be 20mm and I find it very hard to believe this would fit).

It's a shame there appears to be no such thing as a 5/6 C - then six NiMH cells could be fitted in the length of five ordinary C cells. If you can find them anywhere, the tidiest solution would be to source 1/2 or 2/3 C NiMH cells (the fraction refers to their length compared to the standard C length), and put six in the battery compartment with a spacer to make use the remaining length. Spacers would also be needed to fit them in the charger.
 
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Given the track record of Pure, could they get anything right? Given that a C cell has a capscity of 5000 mAh and an AAA cell 800, how long would you expect AAA cells to last anyway? A couple of minutes?

Do we know what model this radio is?
 
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I have some AAA NiMH rated at 950mAh and some C NiCd rated 1700mAh. Yes, C alkalines would be more like 5000mAh, but if needs must...
 
Well, I've just measured the length of some batteries, and the results are: C =50mm, AA=50mm, AAA = 44mm. So the AAAs are too short.
I rest my case.

Just as a PS Try THIS and THIS I don't think 0.5mm is going to make much difference.
 
Trev said:
Well, I've just measured the length of some batteries, and the results are: C =50mm, AA=50mm, AAA = 44mm. So the AAAs are too short.
I rest my case.

Just as a PS Try THIS and THIS I don't think 0.5mm is going to make much difference.
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1280px-Batteries_comparison_4%2C5_D_C_AA_AAA_AAAA_A23_9V_CR2032_LR44_matchstick-1.jpeg
 
Trev said:
Well, I've just measured the length of some batteries, and the results are: C =50mm, AA=50mm, AAA = 44mm. So the AAAs are too short.
I rest my case.
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Of course they are too short - that's why an adapter can make up the difference (not just in diameter). No adapter can take length away (and by specification, AA are 4mm too long).

Engineering is about designing to specification, and regardless of the variation in actual sizes out there, the specification says AA won't fit. But, as I explained at length above, even if a cell that is slightly oversized can be bodged into a holder for a single cell, chances are that this radio has a battery compartment which stacks the cells end to end so that the length error is accumulated, and (by specification) the overall length error on five cells will be 20mm (or, if the error is only 0.5mm per cell, 2.5mm - which still won't fit).
 
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Never mind the specs. I just measured some with my digital veneer calipers (using a thin insulator of course) and AAs were the same length as Cs =50mm and the AA to C adaptors that I have seen are just hollow tubes.
 
Too late for you but yet another option is to make sure when getting a portable radio for bathroom use is to check that it uses USB standard for mains power (5V, 2.2A) and you can then use a USB portable power bank. I have started doing this with my old Pure Highway in the works van for listening to TMS through the van radio, freeing up my portable DAB radio to feed an earpiece so I can carry on listening whether in or out of the van (*). Although I could power the Highway from the van's aux power socket the constant stop / starting is a pain as it would need to fire up each time which not only takes time but not good for the charging circuitry.

(*) I was using a Bluetooth transmitter / earpiece from a split feed but the range of this when out of the van often led to it losing touch annoyingly often just as a wicket fell.
 
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gomezz, sadly there was no option for me. I had a load of Tesco clubcard points that were due to expire and only one model available to me . If I had been buying a radio I would have purchased one that was rechargeable and never use batteries in it.

@BH Thanks again,I knew you had to have a reason. I will see if I can get the AA converters, I already have plenty of those and at just £2.99 for 4 converters its worth a try just for curiosity. I do not think lengh would be an issue. The batteries are laid out in a line of 3 above a line of 2, the spring on the line of 3 is 135mm away extended and
160mm fully compressed.

Mike0001 This one.........
https://www.avstorm.co.uk/products/kitsound-ks-jive-dab-fm-portable-radio-black

Looked everywhere but nobody is showing the open battery compartment, even the YT unboxing numpty.
 
trog said:
The batteries are laid out in a line of 3 above a line of 2, the spring on the line of 3 is 135mm away extended and 160mm fully compressed.
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You need a little spare compression just to get the cells in and out, and it is never good to over-extend/compress a spring, but with this layout I agree it should work. I was guessing it would be more like the battery compartment in a torch.

Just for completeness:

IMG_2442.JPG
 
Trev said:
Never mind the specs. I just measured some with my digital veneer calipers (using a thin insulator of course) and AAs were the same length as Cs =50mm and the AA to C adaptors that I have seen are just hollow tubes.
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Shhhhh! Dont tell BH but I might just try to balance 5 AA's wrapped in newspaper to fatten them up in it. Mums the word.
 
@BH, Good, luckilly I was surprised to see the massive spring rather than a bendy flap on metal. Thanks again.
 
I'd be inclined to stick 5 decent alkaline batteries in it and see how it goes before embarking on all the anguish above of trying to use 'wrong' rechargeables. It may be more expensive in the long term, but as long as you can put them in the recycling, using the proper bits may be a better solution.
Of course, given that I understand DAB radios are far more power hungry than analogue ones, it'll probably not go that way, but at least try it (if you haven't yet).
 
MikeSh said:
I'd be inclined to stick 5 decent alkaline batteries in it and see how it goes before embarking on all the anguish above of trying to use 'wrong' rechargeables. It may be more expensive in the long term, but as long as you can put them in the recycling, using the proper bits may be a better solution.
Of course, given that I understand DAB radios are far more power hungry than analogue ones, it'll probably not go that way, but at least try it (if you haven't yet).
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I will more than likely give both a try, I already have the rechargeables & chargers but not sure about 5 new standard AA's at the moment.
I am not expecting great results but its peaked my curiosity.
 
MikeSh said:
I thought you said it took C cells (R14). (Post #56)
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Yes it does but if the AA to C(R14) converters are simply a tube as Trev says then some AA's and a copy of Fridays Metro will be enough to
check if its a viable option and if it does even power up the radio I can see how long they last.

Edit. When I said both I meant rechargeable and standard AA batteries due to the differences mentioned earlier in this thread. Still trying to avoid forking out for 6 C Duracells, not a fan of cheap batteries in things that need infrequent changing as they seem to often leak.
 
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Yes, the AA to C converters are just a hollow tube, and dirt cheap on amazon, though you may have to wait for delivery from China. In the meantime, improvise with loo rolls!

The picture in post 85 confirms what Trev and others have said.
 
trog said:
not a fan of cheap batteries in things that need infrequent changing as they seem to often leak.
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If they last long enough to leak that would suggest the savings using rechargeables would be minimal.
 
I've learned something today: the variability of cell sizes that are supposedly "standard", and that with a following wind it may be possible to squeeze an AA cell into a C gap.
 
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