Battery Charger link
Try the link below for a very nice gel cel charger. I use one to charge a panasonic 6.5 VA powering my Scott Nixon DAC.
http://www.altronics.com.au/cat.asp?cat=11&grp=431&id=K1685
Try the link below for a very nice gel cel charger. I use one to charge a panasonic 6.5 VA powering my Scott Nixon DAC.
http://www.altronics.com.au/cat.asp?cat=11&grp=431&id=K1685
Re: Warning Safety Hazard
...and do not use a knife in your house- someone could be killed
Ralf
Elso Kwak said:Hi,
Please DO NOT use car or motorcycle lead-acid batteries in your living room.
This type of rechargeable battery can produce a stoechiometric mixture of hydrogen and oxygene that is highly explosive. This can blow up your living room and you and your family...
Use these batteries outside, well ventilated!!! Do not overcharge.
2H2+ O2->2 H2O {=Bang=}
...and do not use a knife in your house- someone could be killed
Ralf
Re: Re: Warning Safety Hazard
Hi Ralf,
Oh, you don't take me seriously?
Then have a look here:
http://db.audioasylum.com/cgi/m.pl?forum=tweaks&n=49531&highlight=elso+lead-acid&r=&session=
ralf said:
...and do not use a knife in your house- someone could be killed
Ralf
Hi Ralf,
Oh, you don't take me seriously?
Then have a look here:
http://db.audioasylum.com/cgi/m.pl?forum=tweaks&n=49531&highlight=elso+lead-acid&r=&session=
using batteries
The best way to charge 12V SLA batteries is with a voltage-regulated 13.5V-13.8V powersupply, which is readily available online. Phoenix makes a nice selection. You can hook up as many batteries as you want to the powersupply in parallel to charge, and leave them connected indefinitely without worry. (This is known as "float charging." Battery datasheets are readily available and have lots of info on various charging techniques, etc. When using float charging, current limiting is not necessary.) You need enough current capacity in your powersupply to accomodate all the batteries, of course. A good rule of thumb is 0.2x capacity. For example, if you have 4 7Ah batteries then you have a total of 28Ah of capacity. 0.2x28Ah=5.6A maximum draw. In practice, you won't use anywhere near this amount of draw unless you discharge the batteries to less than 50% capacity.
4PDT "ice cube" relays make a nice switch between the battery and the charger. You should arrange it so that the batteries are charging whenever you are not listening.
Generally speaking, you should plan on capacity sufficient that you will not discharge them to less than 70% capacity in a normal listening session. SLA batteries don't like being heavily discharged.
SLA batteries are quite cheap on EBay, if you're patient and look around a bit. I've bought new 7Ah SLAs for $5 each. Even 2Ah is likely to be sufficient for most people, depending on the power demands of your speakers. In the past, I've used 5Ah carbon-zinc batteries (non rechargeable), and found that they lasted several months.
I have also constructed a 330V SLA battery power supply for use with tubes, which is quite marvelous.
The best way to charge 12V SLA batteries is with a voltage-regulated 13.5V-13.8V powersupply, which is readily available online. Phoenix makes a nice selection. You can hook up as many batteries as you want to the powersupply in parallel to charge, and leave them connected indefinitely without worry. (This is known as "float charging." Battery datasheets are readily available and have lots of info on various charging techniques, etc. When using float charging, current limiting is not necessary.) You need enough current capacity in your powersupply to accomodate all the batteries, of course. A good rule of thumb is 0.2x capacity. For example, if you have 4 7Ah batteries then you have a total of 28Ah of capacity. 0.2x28Ah=5.6A maximum draw. In practice, you won't use anywhere near this amount of draw unless you discharge the batteries to less than 50% capacity.
4PDT "ice cube" relays make a nice switch between the battery and the charger. You should arrange it so that the batteries are charging whenever you are not listening.
Generally speaking, you should plan on capacity sufficient that you will not discharge them to less than 70% capacity in a normal listening session. SLA batteries don't like being heavily discharged.
SLA batteries are quite cheap on EBay, if you're patient and look around a bit. I've bought new 7Ah SLAs for $5 each. Even 2Ah is likely to be sufficient for most people, depending on the power demands of your speakers. In the past, I've used 5Ah carbon-zinc batteries (non rechargeable), and found that they lasted several months.
I have also constructed a 330V SLA battery power supply for use with tubes, which is quite marvelous.
Baaaaaaaaaaaaaaaaaaammmmm!!!
Elso, I don't know exactly what chemical components can be generated inside a car battey, but I can testify these things can explode.
Yes, one day I was turning the key of a car that belonged to a company I worked, and...
Baaaaaaaaaaaaaaaaaaaaaaaaaaaaaammmmmm!!! 
Man, I got out of the car (shaking) and there was acid everywhere on the floor.
The stones on the pavement were white as snow.
People on the street came running to see what happened, it seamed like Bagdad.
I opened the motor compartment with some gloves and the battery had really exploded, it was all opened, I could see the insides.
We had bought that battery one month before in a supermarket.
I really don't know what happened and why it exploded, but they changed the battery (for free, of course) and it never happend again.
Elso Kwak said:Hi,
Please DO NOT use car or motorcycle lead-acid batteries in your living room.
This type of rechargeable battery can produce a stoechiometric mixture of hydrogen and oxygene that is highly explosive. This can blow up your living room and you and your family...
Use these batteries outside, well ventilated!!! Do not overcharge.
2H2+ O2->2 H2O {=Bang=
Elso, I don't know exactly what chemical components can be generated inside a car battey, but I can testify these things can explode.
Yes, one day I was turning the key of a car that belonged to a company I worked, and...
Baaaaaaaaaaaaaaaaaaaaaaaaaaaaaammmmmm!!!
Man, I got out of the car (shaking) and there was acid everywhere on the floor.
The stones on the pavement were white as snow.
People on the street came running to see what happened, it seamed like Bagdad.
I opened the motor compartment with some gloves and the battery had really exploded, it was all opened, I could see the insides.
We had bought that battery one month before in a supermarket.
I really don't know what happened and why it exploded, but they changed the battery (for free, of course) and it never happend again.
Yes. Lead acid batteries will go boom boom. As mentioned by Elso Kwak they produced H2 and O2 in an optimally explosive combination. That's why it is recommended that jumber cables be separated as far as possible when jump starting a car.
SLA batteries are nice since they don't have emit any gasses.
Vic
SLA batteries are nice since they don't have emit any gasses.
Vic
Here is web site buy a guy using Optima gell cells for his battery powered car.
Interesting to see his circuits for charging at 12 volts then using a series conection for 240 VDC 1200 amp (~ 9kW*hours)w/ some serious current.
http://www.jstraubel.com/944EV/EVproject.htm
He also mentions West Marine as an excellent source for batteries and hardware.
My 944 stiil burns fossil fule.
Interesting to see his circuits for charging at 12 volts then using a series conection for 240 VDC 1200 amp (~ 9kW*hours)w/ some serious current.
http://www.jstraubel.com/944EV/EVproject.htm
He also mentions West Marine as an excellent source for batteries and hardware.
My 944 stiil burns fossil fule.
Re: Re: Re: Warning Safety Hazard
hi,
i just want to say, that if you exactly know what you do and if you are experienced and use a good charger (not a bad selfmade)
you can use it without getting damaged.
Greets,
Ralf
Elso Kwak said:
Hi Ralf,
Oh, you don't take me seriously?
Then have a look here:
http://db.audioasylum.com/cgi/m.pl?forum=tweaks&n=49531&highlight=elso+lead-acid&r=&session=
hi,
i just want to say, that if you exactly know what you do and if you are experienced and use a good charger (not a bad selfmade)
you can use it without getting damaged.
Greets,
Ralf
Peter Daniel said:
What sort of circuit are you using for switching charger between batteries and what kind of charger?
I finally got my 4 Panasonic 12V batteries and I'm almost ready to try them
Peter,
With +/- 24 volts you'll get less than 30 watts from the LM3875...
What about 3 batteries per rail?
H|2 venting is only part of the exercise required for lead acid cell safety in your home.
You also need to be concerned about containing the sulfuric acid. Boating supply stores sell nice but somewhat pricey boxes that can help with this. If you are really considering keeping these things in your home, you should familiarize yourself with how to neutralize and contained any spilled or leaked acid. First aid for both eye wash and skin contact is essential too.
On the rare occasion that I work in one of my employers (TPC- the phone company) central offices, I’ve seen some tremendous lead acid cell arrays. I would conject that the only place you are likely to see bigger DC cells would be in a submarine. Large computer room UPS systems use smaller cells in greater quantities. Emergency showers and eyewash stations are never far away.
So what’s my point anyway? I think that 4 car sized lead acid cells in the living room or even basement shouldn’t be taken to lightly. You’ve got better than a half gallon of some very nasty acid, an H|2 generation source and one hell of a lot of potential energy that is just dying for instantiations exothermic release. What can set off the H|2? Low water in the cell is one cause, the plates can arc. Don’t forget the fuses and safety disconnects.
Yup those optima cells are expensive, haven’t even put one in my car (yet), but 4 of those things in my living room seems almost livable.
Now if I had a big electric vehicle like the one in the article, I suppose Ide start thinking about an Aleph for it.
You also need to be concerned about containing the sulfuric acid. Boating supply stores sell nice but somewhat pricey boxes that can help with this. If you are really considering keeping these things in your home, you should familiarize yourself with how to neutralize and contained any spilled or leaked acid. First aid for both eye wash and skin contact is essential too.
On the rare occasion that I work in one of my employers (TPC- the phone company) central offices, I’ve seen some tremendous lead acid cell arrays. I would conject that the only place you are likely to see bigger DC cells would be in a submarine. Large computer room UPS systems use smaller cells in greater quantities. Emergency showers and eyewash stations are never far away.
So what’s my point anyway? I think that 4 car sized lead acid cells in the living room or even basement shouldn’t be taken to lightly. You’ve got better than a half gallon of some very nasty acid, an H|2 generation source and one hell of a lot of potential energy that is just dying for instantiations exothermic release. What can set off the H|2? Low water in the cell is one cause, the plates can arc. Don’t forget the fuses and safety disconnects.
Yup those optima cells are expensive, haven’t even put one in my car (yet), but 4 of those things in my living room seems almost livable.
Now if I had a big electric vehicle like the one in the article, I suppose Ide start thinking about an Aleph for it.
Re: Re: Re: Re: Re: Warning Safety Hazard
I think car batteries produce Hydrogen gas during reaction sometimes which mixed with air is explosive when the mixture is just right. Any spark will make it go:
'Baaaaaaaaaaaaaaaaaaaaaaammmmmmmmmm!'
Or something similar. In Sweden it would actually go:
Boom!!
carlosfm said:
Ok, but I'd still like to find a reason why it happened to me in that car.
Baaaaaaaaaaaaaaaaaaaaaaammmmmmmmmm!
Deffective battery?
Maby, but it's better to happen in a car than in your house.
I think car batteries produce Hydrogen gas during reaction sometimes which mixed with air is explosive when the mixture is just right. Any spark will make it go:
'Baaaaaaaaaaaaaaaaaaaaaaammmmmmmmmm!'
Or something similar. In Sweden it would actually go:
Boom!!
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.