I have a 40 amp battery charger and 6 Trojan 6v batteries in series
parallel for one large bank.

I bought another identical 40 amp charger to install as a backup and
also extra charge capacity. My freezer is 1/2 hp 12 vdc - pulls about
30 amps so when running the genset at anchor to charge and freeze - I
could only net about 10 amps into the batteries as long as the freezer
was running.

Question - what will be the charge rate with both charging the
batteries and freezer operating. Should be 80-30 = 50 ?

Tell us about the battery chargers. Are they simple chargers or the
new modern electronic switching ones? Paralleling old simple battery
chargers to get good output was a no-brainer. Charger A didn't care
what Charger B did.

Newer battery chargers, like the ones with the CHARGED light on them,
are electronic cutoff, or worse, yet, pulsed output superchargers used
to justify their $500 price tags at marine stores. Everyone should
have a $999.95 charger, right? It's gotta be the best!

Newer chargers constantly monitor the state of the charge voltage by
cutting off the output, measuring the battery voltage, then turning
back on to feed it more. If another charger were charging during this
guy's measurement period, he'd say, "Whoa! This battery's at 15V!
He's fully charged and then some!" At this time, this guy would shut
down, totally confused by the parallel charger, which would also be
totally confused if this guy were charging during ITS measurement
cycle. Not good.

Let us know about your charger (make model type)......Don't parallel
the new supercomputer chargers.....



On Tue, 21 Oct 2003 13:50:37 -0700, Baja-Mo
wrote:

I have a 40 amp battery charger and 6 Trojan 6v batteries in series
parallel for one large bank.

I bought another identical 40 amp charger to install as a backup and
also extra charge capacity. My freezer is 1/2 hp 12 vdc - pulls about
30 amps so when running the genset at anchor to charge and freeze - I
could only net about 10 amps into the batteries as long as the freezer
was running.

Question - what will be the charge rate with both charging the
batteries and freezer operating. Should be 80-30 = 50 ?





Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

These are old Lewco chargers - original one is 25 years old. 6
position switch sets voiltage out - 3 are regulated, 3 not. No modern
electronics here.

On Tue, 21 Oct 2003 23:58:08 GMT, (Larry W4CSC) wrote:

Tell us about the battery chargers. Are they simple chargers or the
new modern electronic switching ones? Paralleling old simple battery
chargers to get good output was a no-brainer. Charger A didn't care
what Charger B did.

Newer battery chargers, like the ones with the CHARGED light on them,
are electronic cutoff, or worse, yet, pulsed output superchargers used
to justify their $500 price tags at marine stores. Everyone should
have a $999.95 charger, right? It's gotta be the best!

Newer chargers constantly monitor the state of the charge voltage by
cutting off the output, measuring the battery voltage, then turning
back on to feed it more. If another charger were charging during this
guy's measurement period, he'd say, "Whoa! This battery's at 15V!
He's fully charged and then some!" At this time, this guy would shut
down, totally confused by the parallel charger, which would also be
totally confused if this guy were charging during ITS measurement
cycle. Not good.

Let us know about your charger (make model type)......Don't parallel
the new supercomputer chargers.....



On Tue, 21 Oct 2003 13:50:37 -0700, Baja-Mo
wrote:

I have a 40 amp battery charger and 6 Trojan 6v batteries in series
parallel for one large bank.

I bought another identical 40 amp charger to install as a backup and
also extra charge capacity. My freezer is 1/2 hp 12 vdc - pulls about
30 amps so when running the genset at anchor to charge and freeze - I
could only net about 10 amps into the batteries as long as the freezer
was running.

Question - what will be the charge rate with both charging the
batteries and freezer operating. Should be 80-30 = 50 ?





Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?

On Tue, 21 Oct 2003 17:45:22 -0700, Baja-Mo
wrote:

These are old Lewco chargers - original one is 25 years old. 6
position switch sets voiltage out - 3 are regulated, 3 not. No modern
electronics here.

They'll work fine in parallel. Just be careful not to charge the
batteries too fast! I like to charge at 10% of capacity to get a
good, deep charge. 700AH - 70A charge for 14 hours from dead.

Others will tell you it's 25% but that gets too much "surface charge"
without restoring the plates very well.

The slower you charge, the better.

If you have a 50A load on them, just subtract it from the available
charging amps.

The 40A old AMEL saturable reactor charger my captain took off his 41'
ketch is now nicely charging my shop house batteries in my Union City
29 stepvan...(c; Man, that thing can put out the POWER!.....

It's dual full-wave rectifiers also charge the house batteries WITHOUT
generating a lot of switching noises to screw up my shop.....



Larry W4CSC

3600 planes with transponders are burning 8-10 million
gallons of kerosene per hour over the USA. R-12 car air
conditioners are responsible for the ozone hole, right?