Batteries are charged with current - ie. amps, not volts. You measure
charge in amp-hours, not volts. So a low battery will drop the charger
voltage to the battery voltage. If there is 10% voltage drop in the
cable (which it isn't!) then that is because ALL the current the
charging source can supply is being absorbed by the battery. As the
battery reaches full charge the regulator will reduce the current to
stop the voltage getting too high. As the current is reduced, the
voltage drop along the protection cables will also drop so finally at
end of charge there is no voltage drop in the cable. ALL the current
going through the cable is going into the battery!

All our combiners include a manual combine. Adjustable threshold
settings are not necessary and we eliminated them in 1995 because the
potentiometer was a maintenance item. All our combiners include an
optional 14.2 volt cut-off that you can use to protect a gel type
battery from the high voltages often found on lead acid batteries.

The blue seas unit is just a battery combiner copy of ours. We
invented the combiner in 1993. We are the cheapest. Ours are the only
ones carrying an UNLIMITED warranty. We have sold over 26,000 of them
all on unlimited warranty! We get about 20 returns per year of which
about 15 have nothing wrong with them.

There is an extensive FAQ on battery combiners at
http://www.yandina.com/combInfo.htm

Regards,

Andina Marie Foster,