DIY C.A.P.S. Battery power supply.

[Christo]

Hi,

 

Having built a C.A.P.S. Lagoon server I also decided to build a battery supply to go with it (I really like making things...). I've run it for a couple of months now without issue and at the risk of being flamed by the engineers here I thought I'd share my creation in case anyone else has similar ideas and is wondering or cares to share their own versions...

 

Ingredients:

 

16Ah LiFePOeF4 battery from DEBEN.com | Home

SPower regulated supply module from Fidelity Audio : SPower low noise voltage regulators

Sockets, plugs and cables from Canford - Professional audio, video and broadcast equipment

Switches from eBay - one of the UK's largest shopping destinations

Oak, paint and sheet aluminium from my workshop stash...

 

These things are of course highly subjective but the Lagoon server running from a standard 12v supply borrowed from an old LaCie hard drive already sounded noticeably cleaner, clearer and more spacious to my ears than my previous 2009 Mac Mini with iTunes and Audirvana+. Whilst my system did not reveal any of the server noises that Chris C described in his system before adding the Red Wine Audio power supply this DIY unit still produced a notable leap in audio performance again. Funny how you don't really miss what you haven't heard until you hear it!

 

There're a few LiFePO4 batteries available here in the UK and mainly supplied for use in golf carts. I chose what appeared to be one of the better quality ones with overcharge protection and management circuits built in. I was already convinced by the merits of LiFePO4 power having long used a J Kenny modified HiFace spdif converter powered with this type of battery and by Chris C's results as previously mentioned.

 

The Tracer battery has a separate charge socket and does not accept a charge from the output terminals so I've setup a two way and a 3 way switch. The upper switch allows pure battery output when the lower switch is in the middle "off" position and puts the charger competely out of circuit. With the lower switch flicked up charger power is sent to the output terminals. With the lower switch flicked down charger power is sent directly to the charge circuit of the battery. Both switches in the up position allow for continuous listening without battery run down. I really cannot be sure whether I do notice any audible difference between pure battery power and power combined with the charger supply. As previously stated there was a positive difference changing from a single 12v switch mode server supply when compared to this battery and external USB card supply but this may be down to the SPower module as much as the battery or it could be that the battery is somehow "buffering" the output from the charger.

 

The SPower module quotes a 4v dropout so I choose 8v rather than 9v output to be sure to accommodate this. Acceptable SOtM supply voltages are +6.5v ~+9v. This USB card regulated 8v dc supply module is screwed to one of the brass legs left from my first discarded cheap voltage regulator board and acts as a heat sink.

I felt it important to use good quality connectors and screened cable between the unit and the server so that they are not acting as aerials and picking up noise. I found these at Canford - Professional audio, video and broadcast equipment.

 

It was a fun project to build, considerably less costly than the Red Wine Audio unit but hopefully performs equally well.

 

More pictures here.

[BobAudio]

Nicely Done!

[dpaws]

I must confess to being a little skeptical about improvements using a battery PSU that's placed upstream of the DC to DC converters that lie inside the PC (either integral to the motherboard or as part of the internal PSU). The performance increase will come once either battery or conventional linear supply is fed to each of the required rails for the motherboard. Ie +12V, +5V etc...

 

IMHO any detected improvements can only come from the dirty power from the PC not being fed back into the power distribution network and thus not contaminating the supplies of the other components in the signal chain...

[Christo]

I understand your skepticism and any improvements may well simply be down to PC noise not being fed back into the mains. I felt I heard a notable improvement in space, clarity and detail when I hooked up the battery power and fed the 2 boards separate clean DC supplies. However I also recognise that I wanted to hear improvements however much I may have attempted or pretended to be dispassionate about it...

 

Switching supplies back and forth to further compare is a hassle with changing jumpers and re-booting etc. and frankly more trouble than I can be doing with.

 

I went down this route because I trust Chris C's judgement and experience and I was pretty certain adding a LiFePOeF4 battery supply could only help and not harm. This battery supply also doubles as an uninterruptible power supply to the server which is another bonus feature for me considering the fairly frequent power outages we get here in rural Cornwall.

[Great Gig]

Excellent thread and nice work. I have just ordered a SLA battery to check the merits of battery power, before committing to this method of powering my server. Great links too, I didn't know about the Tracer batteries - big thumbs up from me

[bonkers]

Nice project, as long as you like the sound improvements its a winner!

[Great Gig]

I just looked at the specs for those . . .

 

Cycle Life : 300 Cycles

This is based on charging at a standard rate with a discharge from full capacity to 9V at 5A. Rest time of 30 minutes between charge and discharge. Cycle life is classed as when discharge capacity is at 70% of original. Note that the battery still has a useful life after this.

 

That does not sound brilliant to be honest I would be replacing them nearly every year?

 

DEBEN.com | 12v 14Ah Lithium Polymer Battery Pack

[iago]

That does not sound brilliant to be honest I would be replacing them nearly every year?

 

They are just cautious. After the 300 full cycles the battery is at 70% of the original capacity. Also they explicitly talk about 100% capacity (12V to 9V to 12V) cycles. If you re-charge earlier than at complete discharge, the battery will last longer.

[rick57]

Hi Christo

 

I was thinking of doing something similar - approx what did all the parts cost, and how long did it take to put it together?

 

Cheers

[Christo]

Hi Christo

 

I was thinking of doing something similar - approx what did all the parts cost, and how long did it take to put it together?

 

Cheers

 

Well I did not accurately track time or cost but around £400.00 all in I'd say. Time wise the long bit was making the case because I chose to do some dovetail joints plus painting/varnishing added some time but actually hooking it all up and soldering and was a leisurely rainy Sunday afternoon.

 

Case wise I suspect you could also mildly modify some sort of PC case to suit and produce quite a professional looking item.