On Sun, 23 Nov 2003 19:53:54 +0000, Daniel E. Best wrote:



Lloyd Sumpter wrote:

I'll start with an assumption that may be wrong, but...Assume a battery loses
50% of its charge in 3 months, and it's about 80AH. That means it loses about
.4 AH per day. So it needs about .4 amps CONTINUOUSLY to keep it charged.

Lloyd, sorry to have to point it out, but there's an error in your statement.
.4 amps continuously is .4 x 24 hours/day = 9.6 AH per day.


Oops - I stand corrected! Chalk it up to not enough coffee.

Lloyd

On 23 Nov 2003 16:06:53 GMT, (Hmseconomy) wrote:

What's the minimum amps/volts output needed to trickle charge two marine
batteries to keep them up?

That depends on the size of the marine batteries, the amp-hour rating,
as well as the type of "marine battery"...i.e. starting or deep
cycle.... you have.

Good batteries don't need something to "keep them up", except
occasional use....run the boat.

Can a single small trickle charge panel charge two
batteries at the same time?

Yes, if you use a battery isolator. Lionheart has an isolator between
house and starting battery banks fed from the Windcharger/solar panel
and shaft alternator. The weaker battery has lower voltage and will
get more current through the series diode. The diodes in the
isolator, however, will keep the batteries from discharging each other
at night.

What's the recommended connection method? Need a
diode to protect against overcharging (even with a minimum output panel?). Any
advice would be appreciated.

The series diode in a solar system has nothing to do with protecting
against overcharging. When a solar panel is in the dark, it is NOT an
open circuit. When its charging voltage drops below the battery
voltage connected to it, the battery shoves current through the
darkened solar panel, discharging the battery in the process. The
series diode prevents this.

There IS a charge limiter you can buy to prevent the solar panel from
overcharging (percolating) your battery. It's called a "charge
limiter" or "charge regulator" and is sold by solar companies.


Larry W4CSC

NNNN

On 23 Nov 2003 16:06:53 GMT, (Hmseconomy) wrote:

What's the minimum amps/volts output needed to trickle charge two marine
batteries to keep them up?

That depends on the size of the marine batteries, the amp-hour rating,
as well as the type of "marine battery"...i.e. starting or deep
cycle.... you have.

Good batteries don't need something to "keep them up", except
occasional use....run the boat.

Can a single small trickle charge panel charge two
batteries at the same time?

Yes, if you use a battery isolator. Lionheart has an isolator between
house and starting battery banks fed from the Windcharger/solar panel
and shaft alternator. The weaker battery has lower voltage and will
get more current through the series diode. The diodes in the
isolator, however, will keep the batteries from discharging each other
at night.

What's the recommended connection method? Need a
diode to protect against overcharging (even with a minimum output panel?). Any
advice would be appreciated.

The series diode in a solar system has nothing to do with protecting
against overcharging. When a solar panel is in the dark, it is NOT an
open circuit. When its charging voltage drops below the battery
voltage connected to it, the battery shoves current through the
darkened solar panel, discharging the battery in the process. The
series diode prevents this.

There IS a charge limiter you can buy to prevent the solar panel from
overcharging (percolating) your battery. It's called a "charge
limiter" or "charge regulator" and is sold by solar companies.


Larry W4CSC

NNNN

This cold be handled by a 5 Watt panel such as this one featured on
the Boat/US site. It has a built in diode. BRBR


Thanks to you all for the info on solar panels. BTW, I just bought the 5 watt
panel suggested by jeff. As it turns out, this panel is on sale thru the
BoatUS website for $20 off the list price. A bargain. Thanks again.

This cold be handled by a 5 Watt panel such as this one featured on
the Boat/US site. It has a built in diode. BRBR


Thanks to you all for the info on solar panels. BTW, I just bought the 5 watt
panel suggested by jeff. As it turns out, this panel is on sale thru the
BoatUS website for $20 off the list price. A bargain. Thanks again.