battery bank truck

[solarninja]

Wanting to put a small battery backup system in my truck bed, I plan on running one 100-watt PV module to a 30 amp load controller through to a 100 amp hour 12 volt battery AGM then run that to a 200amp isolator that goes to my alternator my question is how long will it take this battery to charge and how long will it last me on using the auxiliary battery for my sound system airlift helper spring compressor, exterior work lighting, occasionally a battery jump box or small welder plan on hooking up a 1000 watt inverter for 110vAC power. Do I meet my power demands? How long to charge? How long running equipment thanks for the help all!

[PNjunction]

Too many variables, and only you will be able to actually measure the power draw of your devices.

What we DO know is that you don't want to take a battery past 50% DOD, so that means about half the rated capacity. Ie, with a 100ah battery, you only have 50ah to play with daily.

Ignoring your actual power draw, just to recharge a 100ah agm with a 100ah solar panel means you need:

50ah needed to be restored / 5.5 charge current * 1.78 compensation factor = 16 hours or thereabouts.

Nobody has 16 hours of solar insolation. These are NOT sunrise-to-sunset hours but can be looked up online.

If you lived in Los Angeles, that would be it would take about 3 days to recharge in the summer.
If you lived in Pennsylvania, that would take about 6.5 days to recharge in the winter.

You gotta' get a handle on how much power you actually draw, and for how long. This will determine the size of the battery. Then, according to your solar-insolation hours, you figure out how much panel power you need to support that daily in the winter.

If you wing-it, you'll just be throwing money at the dartboard.

[Sunking]

If you have an Isolator using the alternator, then you have no use for solar. The vehicle alternator can generate more power in 30 minutes than that 100 watt panel can generate in a week.

[russ]

If you have an Isolator using the alternator, then you have no use for solar. The vehicle alternator can generate more power in 30 minutes than that 100 watt panel can generate in a week.

Just buy an old junk panel and put it on the roof - a couple of wires can disappear inside to nowhere. The all sides are covered - solar installed and by using the alternator you have the power you need.

[solarninja]

Too many variables, and only you will be able to actually measure the power draw of your devices.

What we DO know is that you don't want to take a battery past 50% DOD, so that means about half the rated capacity. Ie, with a 100ah battery, you only have 50ah to play with daily.

Ignoring your actual power draw, just to recharge a 100ah agm with a 100ah solar panel means you need:

50ah needed to be restored / 5.5 charge current * 1.78 compensation factor = 16 hours or thereabouts.

Nobody has 16 hours of solar insolation. These are NOT sunrise-to-sunset hours but can be looked up online.

If you lived in Los Angeles, that would be it would take about 3 days to recharge in the summer.
If you lived in Pennsylvania, that would take about 6.5 days to recharge in the winter.

You gotta' get a handle on how much power you actually draw, and for how long. This will determine the size of the battery. Then, according to your solar-insolation hours, you figure out how much panel power you need to support that daily in the winter.

If you wing-it, you'll just be throwing money at the dartboard.

Texas summer should provide a decent ammount of light, thanks for the info all, I don't reall plan on a constant draw, just want to be able to play my sterio all night and still be able to start my car in the am, isolated battery will take care of that, but I also want to be able to charge my power tools or run an air compressor anywhere, any time, I think the system will handle my needs fine thanks again

[SunEagle]

Texas summer should provide a decent ammount of light, thanks for the info all, I don't reall plan on a constant draw, just want to be able to play my sterio all night and still be able to start my car in the am, isolated battery will take care of that, but I also want to be able to charge my power tools or run an air compressor anywhere, any time, I think the system will handle my needs fine thanks again

Because you do not have enough pv panel wattage and "useful" sunlight to fully charge that battery in one day it will eventually get below 50% and slowly die. Then you won't be able to run that stereo at night let alone power an air compressor.

[solarninja]

Because you do not have enough pv panel wattage and "useful" sunlight to fully charge that battery in one day it will eventually get below 50% and slowly die. Then you won't be able to run that stereo at night let alone power an air compressor.

I still drive it every day, my 200 amp alternator will charge those batteries in afew blocks, I was thinking a pv module would be useful for camping or if I get stuck in the boonies for a night, I agree though I need to have enough power to charge the bank in a day.

[Sunking]

I still drive it every day, my 200 amp alternator will charge those batteries in a few blocks

Then you have absolutely no need for solar dude. All solar will do is cost money you do not have to spend, never be used, and will only look cool. Your alternator will do more in 15 minutes than a 100 watt panel can do in a week.

What part do you not understand?

[solarninja]

Then you have absolutely no need for solar dude. All solar will do is cost money you do not have to spend, never be used, and will only look cool. Your alternator will do more in 15 minutes than a 100 watt panel can do in a week.

What part do you not understand?

The part I don't understand is why you wanna be rude. I did nothing but ask a question, and I appreciate all members responses save this one

[solarninja]

The part I don't understand is why you wanna be rude. I did nothing but ask a question, and I appreciate all members responses save this one

The point was to have mobile power without having to use petrol. I understand now that one panel ain't gonna cut it, and I probably can't fit enough on my truck for it to work the way I was hopping, thanks for the input

[SunEagle]

The part I don't understand is why you wanna be rude. I did nothing but ask a question, and I appreciate all members responses save this one

Well you can take Sunking's input as rude or you can take it that he is trying to save you some money by telling you not to purchase a solar panel which will not do what you want it to.

I agree with him. Better to put that cash toward something that you really need.

[inetdog]

One thing that has come up in other threads is that current energy and emissions laws are prohibiting an over the road truck from being parked more than a small period of time with the engine left running.
This leads to severe hardship for the driver who is in his sleeping cab wanting to have air conditioning and entertainment.
The best proposed solution has been a small quiet inverter type generator or even a PV and battery system in some cases.

The folks who argue for just using the alternator are making the assumption that the truck will be moved often enough to keep the battery bank charged. We all know the meaning of "assume", right?

[Sunking]

The part I don't understand is why you wanna be rude. I did nothing but ask a question, and I appreciate all members responses save this one

Not being rude, just getting your attention. You were not getting it. You drive every day, have an over sized alternator, and a battery isolator. It does not get better than that. A 100 watt panel is just a waste of money.

[SunEagle]

One thing that has come up in other threads is that current energy and emissions laws are prohibiting an over the road truck from being parked more than a small period of time with the engine left running.
This leads to severe hardship for the driver who is in his sleeping cab wanting to have air conditioning and entertainment.
The best proposed solution has been a small quiet inverter type generator or even a PV and battery system in some cases.

The folks who argue for just using the alternator are making the assumption that the truck will be moved often enough to keep the battery bank charged. We all know the meaning of "assume", right?

Good points. Still for the OP's case the pv panel is too small to help him. Better to spend the money on more batteries charge by his alternator or that very quite gen set.

Funny I have to run my RV engine for about 30 minutes every few weeks to get both the starting and coach batteries back up to full. I hate running that big 12 cylinder engine but the cost of storing it where I can plug in is very hard to find and very expensive. So far no one has complained about me running it while it is sitting at the storage yard.

[Mike90250]

......Funny I have to run my RV engine for about 30 minutes every few weeks to get both the starting and coach batteries back up to full. I hate running that big 12 cylinder engine .......

Dude ! They have these things called PV panels, that keep vehicle batteries topped off while in storage