Tuck camping (not truck camper): Using the F-350's dual batteries for solar storage?

[msitarzewski]

I'm experimenting with short-run camping excursions using a one person tent in the bed of my F-350. The setup is pretty nice, and I have most everything figured out - except for power. I'm looking for feedback on using the F-350's dual built-in batteries as storage for a small solar setup. Here's the plan:

I'd install a small portable solar array that feeds an appropriately sized charge controller. That would be tied directly into the existing Anderson connector that is/was used to charge my RV's solar setup.

During the day (only) I'd use my GoPower 12V 1500 watt inverter when the the panels are providing more power than the used current.

At night (and otherwise), I'd use my device's built in batteries (phone, tablet, laptop, etc.).

Thoughts?

 

[John Frum]

Assuming those are starter batteries and not deep cycle batteries.
To the best of my knowledge drawing them down even 25% will shorten their lives drastically.
Also if you draw them down and they won't start your vehicle its a pita.

 

[Bob B]

I have a diesel truck with 2 batteries and I wouldn't use them that way .... get or make a small stand alone battery for your camping needs.

.... What smoothJoey said.

 

[Hedges]

If starting batteries don't have to cycle because PV keeps them full, then OK for them to deliver a surge for starting something or brief loads.
"small portable array" wouldn't give much. A few hundred watts of glass panels would. Choose the charge rate you want to give your battery.

Here are manuals for Odyssey batteries, starting/deep cycle that could be used in the application. They quote cycle life vs. DoD

https://www.odysseybattery.com/wp-content/uploads/2020/05/US-ODY-OM.pdf

https://www.odysseybattery.com/wp-content/uploads/2020/05/US-ODY-TM.pdf

 

[msitarzewski]

Thanks all. My plan was to use the daylight sun to power the inverter with the batteries only being used for leveling the outputs when clouds pass. After the sun stops providing adequate juice I’d turn off the inverter leaving the batteries at 100%.

It sounds like maybe a few hundred dollars for a separate set of batteries makes more sense. It’s not a huge setup, just to power the laptop and iDevices.

Thanks again!

 

[Hedges]

Here's the brand of AGM I use. It is a bit more expensive and longer cycle life than some of the others. i.e. something cheaper might be a better deal depending on how many times you anticipate draining it.

Sun Xtender Solar Batteries - Photovoltaic Battery

The Sun Xtender Battery line consists of specialty lead-acid solar, photovoltaic batteries, and renewable energy storage batteries manufactured by Concorde Battery Corporation.

sunxtender.com

You can get a PV charge controller which also has B2B input, charges from your alternator only when engine running.
Some I've seen specs for only allow PV up to 25V, so only for "12V" panels not "24V panels.

 

[HRTKD]

Thanks all. My plan was to use the daylight sun to power the inverter with the batteries only being used for leveling the outputs when clouds pass. After the sun stops providing adequate juice I’d turn off the inverter leaving the batteries at 100%.

It sounds like maybe a few hundred dollars for a separate set of batteries makes more sense. It’s not a huge setup, just to power the laptop and iDevices.

It would work, but that ONE time you forget to disconnect...

A separate set of batteries for the solar would be a safer bet. If you're generating plenty of power, the battery doesn't have to be very large.

 

[Hedges]

Separate battery could be used to jump-start yourself. Probably a single battery is sufficient except in really cold weather.
I haven't checked cranking amps of dedicated deep cycle batteries but I think for at least some they are as high as Dual-purpose.
There may be room to tuck an AGM up under the bed somewhere. My K2500 has a fair amount of room.
If hanging from frame rather than (cushioned) body, maybe use rubber mounts.

 

[stienman]

If it's a gas F-350, then the second battery is already an isolated auxiliary battery, and is only charged when the vehicle is in the "Run" position. It's safe to draw that one down 10-20AH, since its draw-down wouldn't affect the starting battery. Connecting a solar charger to it should be fine as well.

If it's a diesel F-350, then the two batteries are parallel, with no isolation, and you will need to understand the consequences of drawing them down, but as long as you're careful and employ a voltage based battery cutoff for your auxiliary loads, you should be able to take 200WH without negatively impacting your starting performance. More than enough for phone charging and other minor loads.

Here's the low voltage disconnect I'm building into my E-350, which has a significant number of similarities to your F-350:

CZH-LABS LVD Low Voltage Disconnect Module. (12V / 30Amp): Amazon.com: Industrial & Scientific

CZH-LABS LVD Low Voltage Disconnect Module. (12V / 30Amp): Amazon.com: Industrial & Scientific

www.amazon.com

There's a cheaper 10A version available as well if you look around.

 

[HRTKD]

While I have a diesel F-350 with parallel batteries, I haven't heard anything on the Ford-Trucks.com forum that would lead me to believe that a gas F-350 has an isolated dual battery system. As far as I know, the gas dual battery is parallel just like the diesel. If this is a chassis cab it may be different from the normal pickup truck configuration.

 

[msitarzewski]

If it's a gas F-350, then the second battery is already an isolated auxiliary battery, and is only charged when the vehicle is in the "Run" position. It's safe to draw that one down 10-20AH, since its draw-down wouldn't affect the starting battery. Connecting a solar charger to it should be fine as well.

If it's a diesel F-350, then the two batteries are parallel, with no isolation, and you will need to understand the consequences of drawing them down, but as long as you're careful and employ a voltage based battery cutoff for your auxiliary loads, you should be able to take 200WH without negatively impacting your starting performance. More than enough for phone charging and other minor loads.

Here's the low voltage disconnect I'm building into my E-350, which has a significant number of similarities to your F-350:

CZH-LABS LVD Low Voltage Disconnect Module. (12V / 30Amp): Amazon.com: Industrial & Scientific

CZH-LABS LVD Low Voltage Disconnect Module. (12V / 30Amp): Amazon.com: Industrial & Scientific

www.amazon.com

There's a cheaper 10A version available as well if you look around.

It is a diesel. Indeed. Thanks for the link!

 

[willo]

I’d swap in AGM cells, then use a battery protect to limit discharging. Keep all your loads DC/12v and no worries.
If you want to add an inverter it’s a different deal, but that idea should get you started.

 

[Hedges]

An idea would be to put in a switch to isolate the second (parallel connected) battery from the first one and use it for inverter.
That way if you do run it down, you still have one battery left to crank engine.

HD-Series - Blue Sea Systems

Up to 600 Amps continuous rating for large diesel engines.

www.bluesea.com

 

[time2roll]

Laptop and devices? Get a 12v adapter and USB charge adapter and skip the inverter to brick charging. Doubt this will have any effect on the existing batteries if you have 200w solar charging each day. Not like you are making coffee or something.

 

[HaldorEE]

If it's a gas F-350, then the second battery is already an isolated auxiliary battery, and is only charged when the vehicle is in the "Run" position. It's safe to draw that one down 10-20AH, since its draw-down wouldn't affect the starting battery. Connecting a solar charger to it should be fine as well.

If it's a diesel F-350, then the two batteries are parallel, with no isolation, and you will need to understand the consequences of drawing them down, but as long as you're careful and employ a voltage based battery cutoff for your auxiliary loads, you should be able to take 200WH without negatively impacting your starting performance. More than enough for phone charging and other minor loads.

Here's the low voltage disconnect I'm building into my E-350, which has a significant number of similarities to your F-350:

CZH-LABS LVD Low Voltage Disconnect Module. (12V / 30Amp): Amazon.com: Industrial & Scientific

CZH-LABS LVD Low Voltage Disconnect Module. (12V / 30Amp): Amazon.com: Industrial & Scientific

www.amazon.com

There's a cheaper 10A version available as well if you look around.

That has excellent range of voltage settings. At the highest settings you could use it for a lithium house battery. That is still going to limit you to essentially a 350W load. If that is enough, well great find!