Truck power outlet for solar panel

Novaz

I just installed a small 100 watt panel on my truck that i use for weekend breaks
is it possible to use the power outlet /cigarette lighter socket to receive power to the battery from the Charge Controller.
I don't have long commutes and was planning to use this panel to put additional charge in the battery.
Thanks
Roy

inetdog

Re: Truck power outlet for solar panel

Yes.
Several concerns to be aware of:
1. The outlet may or may not be switched on and off by the ignition switch.
2. The outlet will typically have a 10A fuse in series, so do not try to run too much current. A 100W panel will be a lot less than 10A, so you should be OK.

BB.

Re: Truck power outlet for solar panel

Remember--It does get back to loads...

A 100 Watt panel in full sun will get 4-6 hours (typical) for ~9 months of the year:

100 Watts / 17.5 volts Vmp = 5.7 amps Imp
4 hours of sun * 5.7 Amps = 22.8 Amp*Hours

A typical car/light truck has around an 80 AH @ 12 volt battery. And should be discharge by no more than 15% or so:

80 AH * 0.15 discharge = 12 AH @ 12 volt car battery.

A deep cycle battery can be discharged by 25 to 50% and still have reasonably long life.

Sometimes, you can wedge in a true Deep Cycle battery (maybe 20% larger AH rating than a car battery) into the vehicle and be very happy.

-Bill

Novaz

Re: Truck power outlet for solar panel

Thanks for the replies
the spare power socket is available in the ignition switch secondary position
but as Bill mentioned i do in fact have room for a secondary battery so thats what i plan on doing
as a secondary question on this would the battery have been okay receiving charge from two separate systems
ie ,alternator and charge controller
Thanks
Roy

inetdog

Re: Truck power outlet for solar panel

Novaz wrote: »

...
as a secondary question on this would the battery have been okay receiving charge from two separate systems
ie ,alternator and charge controller

The major problem would be if both the alternator and the CC were capable of supplying close to the maximum safe charge rate to the battery. When the battery voltage is low enough for the CC to be in bulk mode and the alternator is delivering its maximum output at the same time, the battery may be damaged by up to twice the normal charging current. This could cause it to overheat, overcharge and gas excessively, lose electrolyte, and even suffer plate damage from the high current density.

If the CC's output is well below the optimum bulk charging current for the battery, then this should not be a problem.

Novaz

Re: Truck power outlet for solar panel

This very small system is up and running
installed a Midnite Solar Batter Condition Meter
the condition i see is that even with a brand new Battery its showing
a 20% drop overnite does the battery need to be charged at full rate for a number of hours/days before it will
show a constant 100% charged condition when the truck is not running
with the over cast weather currently in Seattle the panel is barely showing any current despite the 22 volts registering
My daily commute is approx 7 miles each way ,as mentioned i installed the panel and charger to see how the technology works
in reality ,i realise that currently its the alternator that is putting charge to the battery .
I see mention in the BCM manual of putting a switch in the power line with a fuse I have the fuse
but do i lose much by having the LEDs alight when no power going to the battery.
Thanks
Roy

westbranch

Re: Truck power outlet for solar panel

It sounds like you are seeing the 'surface charge' from the alternator degrading overnight.
To be sure tell us the voltages when you stop the truck wen you return to start the truck and the morning voltage... also at only 7 miles you're NOT getting a full charge as the charge is likely only into the BULK phase and never getting to ABSORB.
Do you have any daily loads? The battery needs some exercise!

Novaz

Re: Truck power outlet for solar panel

Thanks for the reply
i will check the voltages this week,
I have been driving with headlights on and will run the fan as well
cant leave the park lights on as they self cancel after a while
Roy

Novaz

Re: Truck power outlet for solar panel

So have had the panel on truck for a week not any real sunny days this week but some interesting readings on the BCM
5.00AM- 8.00AM- 12.00 NOON 3.00PM

MON 70% 80% 90% 70%
TUE 60% 70% 60% 80%
WED 80% 80% 80% 80%
ThUR 70% 90% 90% 70%
FRI 90% 90% 80% 90%

The Battery is 8 months old and the Alternator is putting out 13.9-14.1 Volts
to me this shows that during the day the panel is not picking up enough power due to overcast weather
and so not making up for the draw that the commute puts on battery
the voltage from the panel is 22+/- volts
I am not concerned about getting to 100%as i usually get one long road trip a month which should take care of that
but would like to know if there is anything else to read from these limited results
the overnite gain has me confused
I will collect some more data next week and then install the second battery that will be isolated from the alternator and just receive solar power

ILFE

Re: Truck power outlet for solar panel

Novaz wrote: »

I am not concerned about getting to 100%as i usually get one long road trip a month which should take care of that

You will need to bring your batteries to a full (100%) charge more frequently than once per month. Once per week is more like it.