[drp]

I want to build an external battery pack for a Sony D-25 and a Sony D-11. Anyone have experience or knowledge of the voltage range at which these units can "safely" operate? What I want to keep from doing is building a pack that will fry something.

Both have DC 9V plugs (both with reversed polarity) in the back and both can be run from a 12V DC car adaptor. Question: Do the factory-supplied 12V car adaptors step down the voltage or are they inputting 12.5-13.5 volts? If not stepping down, it would seem that a 12V pack (10 cells) would be the best solution. Or, simply use a 12V gelcell.

I know of one reported external pack for the D25 that was built with six cells (7.2 volts). Curious if this configuration was chosen for minimal good power/cost savings or to protect the circuitry.

I'm thinking that max (safe) power would produce better sound. Please (politely) correct me on this if I'm wrong.... Would an eight cell pack be optimum?

TIA,

Dave

 

[Earwax]

Quote:

Originally posted by drp Question: Do the factory-supplied 12V car adaptors step down the voltage

Yes, the car adaptors step down voltage to 9 Volts.

 

[CD44hi]

Hi,

I cannot help you with the maximum V you could use for the D25. However, I have used this Ratshack power bank. It is phenomenal, it not only can be used as a Charger but also as a PowerAdaptor and a Power bank. It is priced at $39, however some RS have it on sell from time to time at $10! I just grabbed one two weeks ago at a RS in FL.

Here the Max adjustable V is 9 though, may not be what you are looking for, but it worked very well in my case with both D25 and D9s

good luck...

 

[drp]

Thanks, you guys!

When and if you have a moment, could you measure the output voltage of your 12V adaptor and RS Powerpack? RE: I measured the supplied Sony 9V adaptor and got 11.26 volts. This matches about what a normal 8-cell pack would measure when fully charged. Almost thinking this would work, but hoping for more clarification, since finding D25s can be tough enough……

I'd like to be able run solely on DC because my house current really bites. Haven't even tried the wallwart that came with my Headsave Tempo, only the 16-cell pack I built specifically for its use. I also camp a lot so want something that will run the Tempo and the D25 for several days without recharging. Being an RC nut, I already have tons of cells and several chargers/conditioners to choose from, and simply love building packs.

Hmmmm, If an 8-cell pack would in fact work, do you think I'd even be able to detect a difference between that and a 6-cell pack, sonically speaking?

 

[PeterR]

The stock supply puts out 13.5V unloaded, 11V powering a D-250 in play mode...The voltage gets regulated down to 7.something V internally in the player, so anything above about 9V will just be used to heat up the pass transistor.

 

[drp]

Edited for silly question retraction......

 

[DanT]

I used a denon DCP-100 (require 9V) with a 12V lead-acid for about 6 month before I made some internal battery pack. And It's still functioning.

The stock wallwart If I remember correcly also had like peter said 13.5 V unload and ~11V load ( I don't have a funtional multivolmeter anymore to remake the mesurement) Because those vintage drain batteries like mad and I had enough of keeping changing batteries (8 cell battery pack) and the batteries always died on some good part of the music. Not that I would lisen to music I don't like.
I had only a cheep 8 cell charger which I don't believe is very good. I think pretty bad because it only charge with a timer . Maybe it kill the life of my battery with overcharging

When I saw the load I said what the heck I'm trying it. Well it's not dead yet. . But If some think the CD-player was heavy. Now a 12V 4ah seal lead-acid is very very heavy. But I got it for free. Anyway now I have an internal battery for the dcp-100. And I use the Radioshack powerbank for my other 6V player

 

[drp]

Hmmm, don't think that I'll attempt a 12V source on the D-25 . . but I do see a few older players in the corner that might "volunteer" for an ongoing experiment with rechargables.

Glad to read that 8-cell rechargables worked for you. That's also good news because I have several pre-made 8-cell packs from RC transmitter use (fairly high capacity) so just need to make a connector change for the "experiment." Who knows, they might just be the ticket.

Tangent's DIY PS is starting to look mighty sweet, plan to build one soon. Just hate using this noisy AC in the mean time.

Thanks for responding

 

[DanT]

A few thing I learn with the 8 cell pack. The first one I made had a very short flimsy powercord. It was nothing else than the small black and red 9V connector solder to a dc-plug. I just put it in my backpack so each time it move around it would pull on the wire and put strain on the connection. I almost had an heart attach when I heard my cd-player go pzzzb and die It coun't play anymore. Fortunatly it was just the wire that broke from the connector.

Secondly the player realy don't like to be pull by the DC connector especialy those 9V connection that are not tight fit it can move somewhat. More often than not it would loose power.

So if you make a battery pack don't just trow it in you backpack you need a way to make it stable so it doesn't pull on the connector and try to not put pressure on your connector if you put your cd player in a backpack .
Don't make the power cord too short and flimsy
Don't leave the battery pack connected to your cd player when you don't use it. If connected it will discharge the battery overnight so you have to recharge them all over again. It's especialy fustration the next day when you realise that you have to wait 8 hours for your slow charger to charge the batteries. Get a decent charger with a chip that detect when it's fully charge.

 

[drp]

Dan - That's some adventure in portables… If I'm on the go-go, I'll use my Palm T3 or S84 radio, and continue saving up for a 6th gen (by the time I have the bucks) iPod or similar HD player. I'll transport the D-25 in the case and padded; only use while at rest, and remember your post if I get any bright ideas. Sounds like all was well in the end, though. (This is all coming from a guy that, in the old days, strapped a Palm Pilot and GPS receiver to his mountain bike to map trails.......)

As a long-time RC nut, I've had a bit of experience with batteries, always use beefy wiring, and have a battery conditioner that will discharge/peek charge just about anything (except lith); even does a great job on my 9.6v Plainviews (they measure 156mAH, not 170, by the way….). If you saw my post on the pack I use for my Tempo, it even charges this 16-cell monstrosity (safely) in just a few hours.

Speaking of bright ideas….. In looking at the Tangent's PS, I'm beginning to wonder if this is overkill for a pcdp (or maybe I'm too lazy to etch a board), so looking at a Velleman K1823 for the D-25, and wait and build Tangent's PS for my amp.

 

[DanT]

First I don't know much about DIY. I was searching for a way to connect my 6V dcp-150 and I had the idea using a DC-DC converter to hook up the 12V lead-acid to a 6V regulated. But insead of the Velleman K1823 I stumble upon the Audiocom Q-Power fix voltage regulator less than 1mV noise with Black Gate capacitor for all storage and decoupling. Then I said to myself wait a minute that 88.75$ + shipping for a regulator and I am not even sure it gonna work well not forgeting that I have to carry around the heavy 12V. So I end up with a radioshack powerbank insead which work pretty well for now. I like the powerbank because I don't have to remove the battery from the charger to recharge or to use it as a battery pack. I just had it for a couple of days but it look good so far