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RichB
27-05-2012, 10:01
Hi guys,

As i might have mentioned on my other thread I'm planning to use the Mini T to power some Ditton 15s for some outdoors fun (garden/street parties) in the near future and whilst i expect i can just run an extension from the house it got me wondering about the potential for battery powering the Mini T for a sort of non mains dependant sound system.

Wondering if:

Can this be done?

Is it safe? (i.e. will I blow up the amp or start a fire or something?)

What connections would i need to make to a common type leisure battery?

How long would it power the amp for at a reasonable volume (say 50-60%)?

Any other bits and bobs i would need to have a stand alone ipod powered system?

Any help greatly appreciated. Rich

spendorman
27-05-2012, 12:02
I am sure that someone will give more elaborate advice than this, but if I were doing this, main features would be a suitably rated fuse in the supply circuit, and a suitable cover for the battery to stop anything metallic shorting the battery terminals.

Roy S
27-05-2012, 12:17
You could maybe use one of those portable power stations

Puffin
27-05-2012, 12:23
If it takes 12v DC then any battery with that voltage will do. I have used an SLA 12v (nominal 13.8vDC) with a Tripath T-Amp. I made up some smoothing caps to go with it, although that is not neccessary. You could add a fuse for safety, something small.

spendorman
27-05-2012, 13:36
You could maybe use one of those portable power stations

Good idea, an extra suitable fuse in line would still be sensible.

Martinh
27-05-2012, 16:45
Just need a fuse to protect the system ****this is essential*** i reckon a 3A would be ample. I once saw a chap burn his hand on a shorted wire in his car and it wasnt pretty.

If you are running at max output, your current draw will be around 2A I guess.

Therefore a 50 A/hr leisure battery will last 25 Hours from fully charged. At normal levels, it will last for days...

Be careful not to fully discharge the battery - most batteries don't like this. Keep the battery voltage above 6v under load.

Hope this helps,

RichB
28-05-2012, 11:10
Thanks for all the advice guys, so its not as straightforward as it might seem, wonder if the t-amp is loud enough to drown out the noise of the petrol genny my mate has lying around :lol:

snuffbox
04-06-2012, 14:11
Leisure batteries are designed to be run to near flat before recharging,not like car batteries.
Glad you started this thread as I'm looking for a decent cheap amp for my caravan.

RichB
05-06-2012, 22:02
A mate used to have 2 leisure batteries in his camper van, one he used to power his laptop with and another connected to a solar charger thing which kept it trickle fed. Seemed quite effective in keeping the LED lights on.

I expect you'd be fine with it connected to an AC outlet in the caravan as this must be have some sort of regulator... my problem was how to actually link the thing up to a battery then the guys started on about fuses and a short in my brain occured.:lol:

nat8808
10-06-2012, 00:32
What is a leisure battery? Is it anything like a leisure suit?

I used a large SLA battery with my Bantam.

Was very simple to do - I cut off the DC plug end of a duff wall wart (one that was the correct size for the Bantam), stripped the wires at the other end and connected them to the terminals on the battery.. However, ** THIS IS NOT SAFE **.

Instead you do need to add in an in-line fuse (from Maplin or Halfords or any good motorfactors or electrical store). Just goes in between one of the wires from the cut up wall wart and one of the battery terminals. And you need to make sure the wire used can handle more than the rating of the fuse (silly if the wires burned out before the fuse did). And make sure the terminals aren't exposed, so they can't be shorted (I covered mine in electrical tape) or the battery could make a thick screwdriver glow orange and explode the battery, such is the current capability of them...

The SLA battery I used was a big one, being thrown out at a theatre I worked at, free - wasn't lasting long in their Genie (an electric extendable tower thing on wheels) but still read 13.5V since it's last charge a few months previously and I ran the Bantam for a few weeks at normal listening levels without the voltage dropping at all!

The size battery I used would probably cost £70 new. They are designed to be constantly topped up rather than drained (not a good choice in the theatre machine then!?). Maplin currently do a large solar trickle charger for SLAs etc

aquapiranha
10-06-2012, 09:35
when I had the Trends TA 10.1 (which I still regret selling) I used it with an SLA and a motorbike charger that could keep the battery in tip top condition. You can see it here..

http://i205.photobucket.com/albums/bb256/aquapiranha/trends/CIMG3058.jpg

I have to say though, even using very detailed and sensitive speakers I honestly could not hear a difference. Mind you, the amp had been modified quite a bit so maybe it was already working to it's full potential. I had toyed with the idea of using a PV panel to charge the battery too.

snuffbox
14-06-2012, 21:08
Leisure battery's are like car battery's but designed to withstand deep discharge before being recharged,usually used for powering caravans etc.

Reid Malenfant
14-06-2012, 22:02
Leisure battery's are like car battery's but designed to withstand deep discharge before being recharged,usually used for powering caravans etc.
:) Indeed, spot on!

RichB
14-06-2012, 22:34
Thanks for the feedback guys, since the sunshine did a runner I've shelved any plans for a mini t fuelled outdoor extravaganza. Mrs B and I are planning a trip to the lakes and whilst the idea of enjoying some quality tunes amongst the natural beauty of the surroundings is enticing I cant see her putting up with me packing the dittons! :eyebrows:

Besides, a few days with nothing to listen to but natures own soundtrack might just be what the doctor ordered.

Perhaps the weather will improve and I'll still get to have that BBQ with my tunes outdoors at some point.