SounDigital SD1800.1D clamp testing, SPL testing, review.

[murilo 10+ year member]

but you posted this thread without the test with your engine on....so your test is invalid.



You posted that you had a charger on it, but most of the people on this site don't realize that chargers usually run high voltage, low amperage. Since you didnt divulge what model number or brand your charger was, this even makes you more guilty.

There is no way of having higher voltage without current on chargers...

 

[murilo 10+ year member]

Okay, correct me if I am completely wrong. Noah is basically partly draining his batteries due to the current draw of the amp. So, you can basically model this situation as maybe putting two batteries @ 50 or 75% of their full charge (I have no idea how much he emptied his batteries) on a high voltage charger. Obviously the batteries need to be charged back up to their 100% capacity. So, if I take a battery that's drained to 50 or 75%, put it on a battery charger and put a dmm on the battery, it's going to read the actual batteries float voltage? You're telling me that his truck dropped to 12 or 13 V with the battery charger on?

Sorry, you are wrong.

There is no such thing as high-voltage charger, is a 12V charger that provides it nominal current around 2V above the fluctuation voltage of a battery (12.6V). If the charger supply more voltage the battery would excessively heat and damage.

Being a 40A charger, it can provide the 40A at those 14.5V (normally it will have a less than that because this chargers normally use small transformers, but lets assume that is infact 14.5V at 40A)

The amp have a overall eff of 80%, so the input current will pass 250A. The charger will provide 40A and its voltage will drop, because it is his maximum. The voltage wont keep high, the larger the load the less voltage on a power source. Than the batteries will feed the amp (because their voltage wont go down so easily as the charger) AND their voltage will go down because will be flowing 100A each.

If you have any doubt just pick a similar charger, take out the battery of your car, plug the car cables on it and star the engine, and see what happens with its voltage.

 

[tommyk90 5,000+ posts]

Sorry, you are wrong.

There is no such thing as high-voltage charger, is a 12V charger that provides it nominal current around 2V above the fluctuation voltage of a battery (12.6V). If the charger supply more voltage the battery would excessively heat and damage.

Being a 40A charger, it can provide the 40A at those 14.5V (normally it will have a less than that because this chargers normally use small transformers, but lets assume that is infact 14.5V at 40A)

The amp have a overall eff of 80%, so the input current will pass 250A. The charger will provide 40A and its voltage will drop, because it is his maximum. The voltage wont keep high, the larger the load the less voltage on a power source. Than the batteries will feed the amp (because their voltage wont go down so easily as the charger) AND their voltage will go down because will be flowing 100A each.

If you have any doubt just pick a similar charger, take out the battery of your car, plug the car cables on it and star the engine, and see what happens with its voltage.

Actually, just to correct you about the charger voltage, my 2/20/200 amp 12v charger will push the voltage past 15 volts on the 20 amp setting. I've had numerous chargers do this.

However, noah's results are only going to get better once he turns the car on and has 220 amps @ 14+ volts at his disposal, so I think a lot of people are getting in a big stink over nothing.

 

[basebalz13 10+ year member]

I will try to post these results tomorrow. Truck off, Truck on.
What's a little more impressive to me, is that it seems I have very little impedance rise.

//content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

nG

nice efficent system then,

 

[basebalz13 10+ year member]

times 2 tommyk, those results will only go up once he uses the actual truck.

btw why is everyone flaming nG for useing a battery charger, iirc jacob at sundown does the same when he clamps is amps none of yall go against his testing methods....

 

[MatcoGuy456 10+ year member]

times 2 tommyk, those results will only go up once he uses the actual truck.
btw why is everyone flaming nG for useing a battery charger, iirc jacob at sundown does the same when he clamps is amps none of yall go against his testing methods....

Lol I find it funny you just repeat what people say to make it look like you know what you're talking about. Yet you posted earlier and never said anything like this untill tommy did. Comical.

 

[Lakota 5,000+ posts]

Sorry, you are wrong.

There is no such thing as high-voltage charger, is a 12V charger that provides it nominal current around 2V above the fluctuation voltage of a battery (12.6V). If the charger supply more voltage the battery would excessively heat and damage.

Being a 40A charger, it can provide the 40A at those 14.5V (normally it will have a less than that because this chargers normally use small transformers, but lets assume that is infact 14.5V at 40A)

The amp have a overall eff of 80%, so the input current will pass 250A. The charger will provide 40A and its voltage will drop, because it is his maximum. The voltage wont keep high, the larger the load the less voltage on a power source. Than the batteries will feed the amp (because their voltage wont go down so easily as the charger) AND their voltage will go down because will be flowing 100A each.

If you have any doubt just pick a similar charger, take out the battery of your car, plug the car cables on it and star the engine, and see what happens with its voltage.

I'm curious to test out how the voltage across the terminals of a battery charger will change with the current draw of the batteries to the amp. I guess it depends on the voltage regulation that the charger allows on the secondary winding of the transformer.

 

[Lakota 5,000+ posts]

I know that all of my buddies 40A chargers charge at 18V+ when the dial is turned to 40A.

 

[Sparkomatic 10+ year member]

Well all I got to add this is one day u all will see how much power these lil amps make. I know that they make tons and sound better than any other class D amps i heard on the market. It is small which is awesome and it kicks *** in power for its size. My 8K's yeilded 8,839.6 with a rise of 4.36 ohms

 

[ngsm13 5,000+ posts]

I'm curious to test out how the voltage across the terminals of a battery charger will change with the current draw of the batteries to the amp. I guess it depends on the voltage regulation that the charger allows on the secondary winding of the transformer.

I'll see if I can test that too. Without testing, my original thoughts were that it would act similar to an alternator.

nG

 

[murilo 10+ year member]

Actually, just to correct you about the charger voltage, my 2/20/200 amp 12v charger will push the voltage past 15 volts on the 20 amp setting. I've had numerous chargers do this.
However, noah's results are only going to get better once he turns the car on and has 220 amps @ 14+ volts at his disposal, so I think a lot of people are getting in a big stink over nothing.

You should never charge a lead-acid battery over 14.4V. This represents 2.4V per cell and it is the limit, above that you have corrosion on the lead plates and you kill the battery pretty fast.

This is exactly why the decent chargers have a over-voltage protection above 14.5 or 14.6V, they will shut down to save the battery. Also is why the car alternators fluctuate between 13.8V and 14.4V (the real max voltage to apply).

The hotter the temperature the worse. In a hot room you should always apply max of 13.8V.

If you have been charging your bats at 15V you certainly damaged them.

 

[tommyk90 5,000+ posts]

You should never charge a lead-acid battery over 14.4V. This represents 2.4V per cell and it is the limit, above that you have corrosion on the lead plates and you kill the battery pretty fast.
This is exactly why the decent chargers have a over-voltage protection above 14.5 or 14.6V, they will shut down to save the battery. Also is why the car alternators fluctuate between 13.8V and 14.4V (the real max voltage to apply).

The hotter the temperature the worse. In a hot room you should always apply max of 13.8V.

If you have been charging your bats at 15V you certainly damaged them.

I never charged it that high for more than a second or so, because I saw how high the voltage climbed.

I was just stating that with the old style chargers it is possible to get higher voltage out of them.

 

[murilo 10+ year member]

I know that all of my buddies 40A chargers charge at 18V+ when the dial is turned to 40A.

I'm pretty sure you see 15 or 18V with no load, no battery should be charger at more than 14.4V without excessively heating and damaging. Remember also when measuring that you should measure the RMS voltage under load, if you use cheap meters they will be crazy because the chargers don't have filtering, just the diodes after the windings, the battery actually acts like a filter.

If they really charged at 18+ the battery is already in battery heaven.

 

[basebalz13 10+ year member]

Lol I find it funny you just repeat what people say to make it look like you know what you're talking about. Yet you posted earlier and never said anything like this untill tommy did. Comical.

because i was away from the thread for a minute, then i got back and was on the phone with exige audio talking about this thread, then i told him what i was about to post, but i posted the comment about the efficent setup first, thats when then i saw tommyk already post something similar to what i was going to say...

 

[Lakota 5,000+ posts]

I'm pretty sure you see 15 or 18V with no load, no battery should be charger at more than 14.4V without excessively heating and damaging. Remember also when measuring that you should measure the RMS voltage under load, if you use cheap meters they will be crazy because the chargers don't have filtering, just the diodes after the windings, the battery actually acts like a filter.
If they really charged at 18+ the battery is already in battery heaven.

I don't understand what you're trying to get across. The root mean square is for alternating current, not direct current.