12 volt question

Lifes Good

So an area I am not so good on is electrical or at least understanding the charging system. The charger is a intelli model PD2030.  The batteries are new last year.  Two starting deka 24m7 MCA 1000. Top off charge 13.8.  Two house deka cca 575 23 amps ave 200 min.  Top off charge 12.6.

When looking at my GPS volts on screen it says 12.3.  Why the difference from 12.6?

Should the house have higher topped off volts?  

Is my charger kicking off when the starting battery reaches full leaving the house not maxed out?  The green light is flicker fast indicating full charge.

I tested the batteries today an they passed as far as being full and working properly.

Thoughts please?

mvn

One explanation can be your measuring points.  GPS might be measuring the voltage at the helm; batteries at the battery posts.  There will be voltage drops over the wiring harnesses given the distances involved.  Meters might be calibrated differently as well.

 

Mark

212rowboat

you're going to lose some charge along the way... it's just the nature of voltage/amperage..

..check this out..

but that isn't likely your culprit by itself.. other items are going to be pulling load while underway, as well, which will also drop your vdc.. but still, that likely isn't it..

this most likely  is: voltage ripples (aka peak-to-peak) is common from batteries to end of line components... think of your battery like a big ol' reservoir high on the mountain, and with smooth surfaces (good for water skiing, no?), and the wires like little rivers of juice running from the reservoir- the surface of the juice in motion is rippled just like a proper white water rafting river would be.. it hits the component in this manner, and is absorbed- and the component (in your case, a GPS, and a pretty 'smart' device) likely has capacitors and resistors ready to negotiate the current into a steady manageable source- which likely means taking the edge off the current- which likely means absorbing more than it uses previous to the capacitors and resistors.. and is dispelled in terms of heat...

I bet you can feel a warmth on the back of your GPS display, huh?

if it's putting the freak on you, don't let it, or regulate it by installing a one in line...

that's my 2 cents, anyway.. :-)

re: battery- another thread mentioned something similar to this, but I thought better of interjecting anything there, but lead acid is tough stuff.. it can handle as much as 18vdc in, likely, for a pretty good time.. it will be hot as hades during such an extended event, though, as it now becomes the end component, and it doesn't have anything but plates and juice to absorb the ripples because it's not smart like most your components are.. once those plates and juice absorb all they can and it's still receiving the voltage it can't disperse- there is only one thing it can do, and it ain't pretty..

mvn

Here's an interesting website with a voltage drop calculator.  I keyed in 12 gauge wire, 25' wire length, 2.5 amp load, 12 vdc.  Voltage drop is 0.204 volts.  The higher the load, the higher the drop.  Like Drew said, it can depend on your load.

http://genuinedealz.com/voltage-drop.html

 

Mark

Lifes Good

Thanks Guys.  I guess my starter batteries can hold a higher charge on avg.