Fusing a Battery Supply?

mourip · 31st January 2006, 07:11 PM

Hi,

Have any of you who have put one of the various T-Amp flavors into a new chassis, and used an SLA battery, added a fuse to the supply?

Thanks,

Paul

Pano · 1st February 2006, 10:28 AM

Yes, I have. IAnd have never blown a 2 amp fuse, but you could use 3A if you thik 2 is too small.

A fuse is a good thing, just don't make it too big.

dnsey · 1st February 2006, 11:39 AM

I'd considera fuse essential - as near as possible to the battery. Thre's a lot of energy stored in even a small SLA at low internal resistance, quite enough to start a fire under fault conditions.

mourip · 1st February 2006, 12:02 PM

Thanks for the replies. Since no one ever mentions it I had assumed that folks did not consider it necessary with a battery.

I already had one mishap with my modded T-Amp. I inserted the battery charger adaptor into the chassis female mount and it bent the hot pin to the chassis. The result was that I let a lot of smoke out of the amp and the little battery pumped its heart out in a brilliant display of excess. Luckily the internal wiring acted as a large low value resistor and bought me enough time to yank the adaptor out before a real fire started. The amp board was unharmed.

Fuses are good...

gfinlayson · 1st February 2006, 12:19 PM

Lead acid batteries can discharge a huge amount of energy in a very short time.

There are lots of accounts of accidents occurring with vehicle batteries and spanners. The average vehicle battery can deliver several hundred amps when shorted making it a very effective DC arc welder.

pburke · 2nd February 2006, 09:22 PM

I recently taught my kids about how strong battery current can be by shorting out a small 7.2aH SLA battery with a piece of CAT5 wire - instant smokage and red-hot melting copper...

I use a 5amp fuse in my battery powered DDDAC, which draws about 1 amp - it has saved a few components quite frequently. Just last week I bought a new box of 5amp automotive fuses. I can't find them any smaller, but I'm putting this fuse only in there for the "bonehead mistake protection"

Peter

31st January 2006, 07:11 PM	#1
mourip diyAudio Member Join Date: Apr 2004 Location: Washington, DC	Fusing a Battery Supply? Hi, Have any of you who have put one of the various T-Amp flavors into a new chassis, and used an SLA battery, added a fuse to the supply? Thanks, Paul

1st February 2006, 10:28 AM	#2
Pano diyAudio Moderator Join Date: Oct 2004 Location: North Carolina Blog Entries: 4	Yes, I have. IAnd have never blown a 2 amp fuse, but you could use 3A if you thik 2 is too small. A fuse is a good thing, just don't make it too big. __________________ Take the Speaker Voltage Test!

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
C- Battery Supply	dsavitsk	Tubes / Valves	4	14th May 2008 09:08 PM
Battery supply.	harwoodspark	Analog Line Level	10	23rd December 2007 05:28 PM
What happens if the battery supply is off balance ?	Will	Chip Amps	3	6th October 2006 04:39 PM
Battery Power Supply	PH	Analogue Source	4	3rd May 2005 12:03 PM
Battery Supply Help.	RichardJones	Solid State	4	11th June 2003 02:23 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

1st February 2006, 11:39 AM	#3
dnsey diyAudio Member Join Date: Mar 2004 Location: Shropshire, England	I'd considera fuse essential - as near as possible to the battery. Thre's a lot of energy stored in even a small SLA at low internal resistance, quite enough to start a fire under fault conditions.

1st February 2006, 12:02 PM	#4
mourip diyAudio Member Join Date: Apr 2004 Location: Washington, DC	Thanks for the replies. Since no one ever mentions it I had assumed that folks did not consider it necessary with a battery. I already had one mishap with my modded T-Amp. I inserted the battery charger adaptor into the chassis female mount and it bent the hot pin to the chassis. The result was that I let a lot of smoke out of the amp and the little battery pumped its heart out in a brilliant display of excess. Luckily the internal wiring acted as a large low value resistor and bought me enough time to yank the adaptor out before a real fire started. The amp board was unharmed. Fuses are good...

1st February 2006, 12:19 PM	#5
gfinlayson diyAudio Member Join Date: Jan 2006 Location: Aylesford, Kent, England	Lead acid batteries can discharge a huge amount of energy in a very short time. There are lots of accounts of accidents occurring with vehicle batteries and spanners. The average vehicle battery can deliver several hundred amps when shorted making it a very effective DC arc welder.

2nd February 2006, 09:22 PM	#6
pburke diyAudio Member Join Date: Nov 2003 Location: Madison Wisconsin	I recently taught my kids about how strong battery current can be by shorting out a small 7.2aH SLA battery with a piece of CAT5 wire - instant smokage and red-hot melting copper... I use a 5amp fuse in my battery powered DDDAC, which draws about 1 amp - it has saved a few components quite frequently. Just last week I bought a new box of 5amp automotive fuses. I can't find them any smaller, but I'm putting this fuse only in there for the "bonehead mistake protection" Peter

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)