Boat battery question???
 

On Tue, 23 Jun 2009 12:12:42 -0400, Wayne.B
wrote:

On Tue, 23 Jun 2009 15:58:11 +0000, Larry wrote:

Mac? Don't you have 4 500A alternators in parallel so you can charge the
house batteries in 5 minutes, like some boats I know?....(c;]

We have a pair of 250 amp alternators. They won't charge the
batteries in 5 minutes, but at half power they will drive a 2500 watt
inverter at full output.

http://www.alternatorparts.com/Extreme%20Duty%20Dual%20Rectifier%20CS-144%20type.htm

Without a battery that would be in the region of 200 amps, not
considering system loss.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Boat battery question???
 

On Wed, 24 Jun 2009 16:10:49 +0700, Bruce In Bangkok
wrote:

Mac? Don't you have 4 500A alternators in parallel so you can charge the
house batteries in 5 minutes, like some boats I know?....(c;]

(It's not funny...I actually saw one like this!....with kids aboard going
offshore!)

How much voltage do you need to pump 2,000 amps into a battery?

More to the point, how much battery do you need? I'd estimate about
40 pairs of golf cart batts at about 120 lbs per pair. Maybe the
question is "how much boat do you need" ?

Boat battery question???
 

On Wed, 24 Jun 2009 16:15:09 +0700, Bruce In Bangkok
wrote:

We have a pair of 250 amp alternators. They won't charge the
batteries in 5 minutes, but at half power they will drive a 2500 watt
inverter at full output.

http://www.alternatorparts.com/Extreme%20Duty%20Dual%20Rectifier%20CS-144%20type.htm

Without a battery that would be in the region of 200 amps, not
considering system loss.

Yes, and there are losses, even with big cables and heavy duty lugs.

Boat battery question???
 

"Bruce In Bangkok" wrote:


How much voltage do you need to pump 2,000 amps into a battery?


How muich time do you have?

Lew

Boat battery question???
 

Bruce In Bangkok wrote in
:

How much voltage do you need to pump 2,000 amps into a battery?



How dead is it?

--
-----
Larry

If a man goes way out into the woods all alone and says something,
is it still wrong, even though no woman hears him?

Boat battery question???
 

On Wed, 24 Jun 2009 18:43:20 GMT, "Lew Hodgett"
wrote:


"Bruce In Bangkok" wrote:


How much voltage do you need to pump 2,000 amps into a battery?


How muich time do you have?

Lew

What? Amps have nothing to do with time.

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Boat battery question???
 

On Wed, 24 Jun 2009 20:57:31 +0000, Larry wrote:

Bruce In Bangkok wrote in
:

How much voltage do you need to pump 2,000 amps into a battery?



How dead is it?

Dead enough to have to charge it :-)

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

Boat battery question???
 

Bruce In Bangkok wrote in
:

Dead enough to have to charge it :-)



25% of AH rating tapering to zero after 12 hours....

Chemistry is slow....


--
-----
Larry

If a man goes way out into the woods all alone and says something,
is it still wrong, even though no woman hears him?

Boat battery question???
 

Bruce In Bangkok wrote in
:

What? Amps have nothing to do with time.


Amps X Hours X charging efficiency as a decimal = AH

Amps have a lot to do with time....



--
-----
Larry

If a man goes way out into the woods all alone and says something,
is it still wrong, even though no woman hears him?

Boat battery question???
 

Bruce In Bangkok" wrote:


What? Amps have nothing to do with time.

Ah but in the case of a battery, they do.

How big is the batttery?

Recharge rate won't exceed 15% average of the battery AH capacity.

For every 100 AH taken out of a battery, you must replace 125AH.

Wet cell batteries are not efficient, just convenient.

As you can see the number of replacement AH put back in a battery is
very much time dependant.


Lew