Manufacturers saving a few cents on wire

Mike134 wrote:


You've gone to the other extreme and it just adds to the confusion.

Voltage drop is a product of wire resistance (it's gauge), wire length, and how much current you try and push though it.

While you are technically correct, you are also omitting some facts.

12V systems are not the same as 120V systems.

12V systems have a very small range of acceptable voltage, 120V systems have a MUCH larger range of acceptable voltage.

120V systems acceptable voltage range is 108V - 135V, a range of 27V.

12V systems have a acceptable voltage range of 10.5V for a dead battery to 14.4-14.8V for max charging voltage. A range of only 4.3V!

With a fully charged battery at rest you have 12.8V, three stage chargers use 13.2V as a "maintenance" charge which ONLY takes care of the self discharge of the battery, it does not recharge a depleted battery at 13.2V unless you are OK with a few milliamps of charge which would take weeks to months if at all to recharge..

To get some sort of meaningful charge rate you need 13.8V AT THE BATTERY and even that is only going to net you a few amps.

Net result in any case is a severely discharged battery that never gets fully charged and severely reduces the life of said battery!

Ever wonder why many folks get on the forum whining about constantly having bad battery issues? Yeah, this IS the reason, they are KILLING the batteries by UNDER CHARGING.


Your size is great if you want to charge at 100amps/hour.

Wrong, anyone with a modern multistage converter from 30A and higher CAN BENEFIT by upsizing the wire size well above what those 120V wire charts say.

For the rest of us a 10amp/hour rate is more than adequate when plugged into shore power overnight.

Wrong again.

You are making bad assumptions, it is well known for BEST battery LIFE, it IS ALWAYS BEST TO RECHARGE THE BATTERY BACK TO FULL OR NEAR FULL AS SOON AS POSSIBLE.

Trickle charging or even a 10Ahr recharge is not going to provide best battery life.

I guess max battery life for you not much of a priority, must be nice to replace batteries often..

I easily get 10-11 yrs out of my batteries, they are not cheap to replace so care and feeding them is a priority to me.

Just for the record any charging voltage over 13.5 will charge the battery.

Wrong again, you NEED 13.8V AT THE BATTERY to effectively charge quickly.

Even old school mechanical auto alternator regulators were SET to 13.8V, if you found one that was not 13.8 you either adjusted it or replaced it with an electronic regulator..

Anything less than 13.8V results in milliamps to perhaps a couple of amps depending on discharge depth.