Please, need help setting up a solar system with batteries and inverter, etc.

[magentawave]

I was in construction for years and know a few things but I am severely electrically challenged (i.e. tarded) when it comes to anything electrical. So to avoid frying myself and my vehicle and/or wasting money on stuff I don't need, I'm hoping some nice people can please help me with how much solar I'm going to need, battery storage, possible inverter, etc., etc. for the 18' Toyota Sunrader that I'm rebuilding now and will be traveling and surfing my way through the US, Mexico, Central America and South America in.

Tt would also be cool if someone could please make me a wiring diagram after I post all the stuff I'll be using for my setup (solar panels, controller, batteries, wires, etc., etc.).

I've read through "Handy Bob's" blog post here on solar stuff. I figure he must know his stuff because he's lived totally off the grid in an RV for the last 8 years...with NO generator!

Here are some details...

-SOLAR PANELS: If the typical 250 watt panel is 3' x 5' then I have lots of room on top for at least two of them.

-BATTERY STORAGE: I might have to rethink everything because batteries are sooo freaking heavy. "Handy Bob" now recommends Crown 6 volt golf cart batteries over Trojan T105's and the Crown 6 volt batteries weigh from 66 to 75 pounds each...aaargh. I'm thinking of storing the batteries in a metal rack that will be right behind the differential and accessible from a trap door in the center of the floor of the Sunrader.

-HIGH CAPACITY ALTERNATOR: I'm thinking of replacing the little stock Toyota alternator (1982 22R) with a high capacity 150 to 250 watt alternator.

-WORK: I have to work along the way which is why I need my laptop and maybe an external LED monitor.

-OFF THE GRID: I don't plan on doing hotels or campgrounds so won't be plugging into AC anywhere.


Here is the energy I think I'll be using in order of energy hogness...

- 12 Volt Fridge/Freezer: 24 watts = 2 amps x 24 hours per day = 48 amp hours. www.TruckFridge.com says "average consumption" is 24 watts an hour for the TF130. I'm going to add an extra 2" of insulation to the top, back, sides, and bottom (excluding around the compressor) to reduce energy consumption.

- MacBook Pro 17: 51 watts = 4.25 amps x 1 to 8 hours per day = 4.25 amp hours to 34 amps. I might replace this LCD laptop for one with an LED display. At 51 watts with an LCD display, can anyone tell me if it would be worth buying one with an LED display?

- *Sceptre 19" LED External Monitor (AC 110 volt): 28 watts = 2.33 amps = x 1 to 8 hours per day = 2.33 amp hours to 18.6 amp hours

- *Electric Razor Charger (AC 110 volt): 8 watts = .67 amps x 8 hours = 5.36 amp hours (Use only twice a month)

- *Apple Airport Time Capsule: 14 watts = 1.17 amps x 1 to 4 hours per day = 1.17 amp hours to 4.7 amp hours

- Fantastic Vent Fan: 3 watts = .25 amps x 1 to 14 hours per day = .25 amp hours to 3.5 amp hours

- Android Phone Charger: 2 watts = 1.7 amps x 2 hours = 3.4 amp hour

- *Juicer (AC 110 volt): 150 watts = 12.5 amps x 10 minutes per day (.2 hours) = 2.5 amp hours

- iPad Charger: 8 watts = .67 amps x 2.5 hours per day = 1.7 amp hours

- iPod Charger: 2 watts = .17 amps x 2 hours per day = .34 amp hours

- Waring 12 volt Blender: 200 watts = 16.7 amps x 1 minute per day (.02 hours) = .334 amp hours

- **LED Lights: I don't know how much these use but I never leave lights on when not needed. Anyone know how much warm white LED dome lights consume?

- *Inverter: I don't know how many watts an inverter uses or what to get but the inverter is for the stuff with a single *asterisk (External monitor, Electric razor recharge, Juicer, Apple Airport Time Capsule).


Minimum amp hours per day: 14 amp hours + 48 amp hours (12 volt TruckFridge) = 62 amp hours per day. **Does not include LED lights yet.

Maximum amp hours per day: 74 amp hours + 60 amp hours (12 volt TruckFridge) = 134 amp hours per day. **Does not include LED lights yet. Why did I put 60 amp hours for the fridge? I dunno but I'm just trying to cover my ******** here for worst case scenario stuff.


The theme throughout the rebuild of the Sunrader is to keep things SIMPLE. Examples of simple are that the bathroom is a simple "wet room" where I can take a "shower" with a 2 gallon black garden sprayer with a shower nozzle, hang wet wetsuits to dry, and the former toilet with black water tank was replaced with a sawdust/compost toilet I built. The water to the faucet in the galley gets there using a manual foot pump like you'd find in a cruising sailboat.

Well thats it for now. What next? Any and all suggestions explained like you're talking to a ten year old will be greatly appreciated!

Thank you very much.

 

[sgtmike3]

I'm far from an expert on solar but I have been reading a lot recently. I would caution you on trying to use the vehicle alternator to charge the battery bank, you really can't charge the two separate systems from the same alternator.

Another source of information, besides Handy Bob, is http://www.jackdanmayer.com/truck_projects_and_improvements.htm Click on Adding a Separate House Bank

Mike

 

[magentawave]

Thanks for the link. I didn't know you couldn't charge the house batteries and starter batteries together. Then what do people do?

 

[4RunAmok]

Thanks for the link. I didn't know you couldn't charge the house batteries and starter batteries together. Then what do people do?

I dunno where he learned that, but it's incorrect. I do it at work all the time.

So long as the main battery up front and the aux battery are of the same type; i.e. both flooded cell, or both AGM, etc. You never want to mix them.

Battery combining systems do this all the time, and the alternator charges both battery banks simultaneously.



See this link for a well written example of how this is done, with LOTS of commentary on the subject...
http://www.expeditionportal.com/for...ke-a-cheap-isolated-dual-battery-setup-for-50

 

[4x4junkie]

Agreed, you can charge both batts from the alt. What is VERY important though is that you have adequate-size wiring going to the house batteries if they are any appreciable distance away from the alt or your isolator. It may sound like overkill, but #1/0 or even #2/0 AWG wiring will greatly benefit your house batteries if their wiring length totals 20' or more. This is because even a 0.5 volt drop will greatly extend recharge times and given the frequently limited amount the engine is running, you want your charge rate to be as quick as possible.

IOW, be sure to keep the voltage loss in your battery cabling to less than 2% or so @ whatever amp rating your alternator is (1.5% even better).


Given your max estimate of 134Ah (approx 1675Wh), I'd shoot for at least 300Ah for the battery bank, and 350-500W of solar. This should provide a good margin of safety should you often hit that maximum, or if you experience a cloudy day or two. The extra solar will also be able to quickly replenish a deeply-discharged battery bank once the sun returns.

 

[zelatore]

While bigger is generally better when it comes to high-current wiring, no sense in just guessing. Here's a handy chart to help you determine appropriate wire size for a given load and % voltage drop:
http://www.westmarine.com/webapp/wc...toreId=11151&catalogId=10001&page=Marine-Wire
Remember, you need to figure round-trip wiring distances. Though with a truck you will likely use the frame as the ground so that's not so much of an issue as it is in a fiberglass boat with no frame.
I also like that 300 A/H capacity. You could do that with 3 group 31s or a better yet a pair of 6v L16s, though at a slightly higher cost.

 

[magentawave]

1) If you guys were starting over and building a brand new interior in a totally gutted Sunrader motorhome, would you run wire for 12 volt LED light fixtures or would you go wireless by using self-contained LED light fixtures that use rechargeable AAA batteries? And if the consensus is to run wires for 12 volt LED light fixtures, then is 16 AWG wire okay?

2) Is the main rating battery manufacturers use to show the amp hours typically based on the 20 hour rating?




This Sunrader was originally built with both the starter battery and house battery under the hood and I'm guessing there is some kind of isolator or solenoid between the batteries so the alternator knows when to stop charging, right? Anyway, do you think the stock "isolator" or solenoid will work for a larger battery bank in the back of the Sunrader?

I dunno where he learned that, but it's incorrect. I do it at work all the time.

So long as the main battery up front and the aux battery are of the same type; i.e. both flooded cell, or both AGM, etc. You never want to mix them.

Battery combining systems do this all the time, and the alternator charges both battery banks simultaneously.

See this link for a well written example of how this is done, with LOTS of commentary on the subject...
http://www.expeditionportal.com/for...ke-a-cheap-isolated-dual-battery-setup-for-50

Yes, big wire is one of the main things that Handy Bob stresses too. If I go with a 300 amp hour battery bank then realistically I can only tap half of that (150 amp hours), correct? And if that is correct then I'm pretty close to hitting that on the days I might need 134 amp hours.

Agreed, you can charge both batts from the alt. What is VERY important though is that you have adequate-size wiring going to the house batteries if they are any appreciable distance away from the alt or your isolator. It may sound like overkill, but #1/0 or even #2/0 AWG wiring will greatly benefit your house batteries if their wiring length totals 20' or more. This is because even a 0.5 volt drop will greatly extend recharge times and given the frequently limited amount the engine is running, you want your charge rate to be as quick as possible.

IOW, be sure to keep the voltage loss in your battery cabling to less than 2% or so @ whatever amp rating your alternator is (1.5% even better).

Given your max estimate of 134Ah (approx 1675Wh), I'd shoot for at least 300Ah for the battery bank, and 350-500W of solar. This should provide a good margin of safety should you often hit that maximum, or if you experience a cloudy day or two. The extra solar will also be able to quickly replenish a deeply-discharged battery bank once the sun returns.

Thanks for the link.

While bigger is generally better when it comes to high-current wiring, no sense in just guessing. Here's a handy chart to help you determine appropriate wire size for a given load and % voltage drop:
http://www.westmarine.com/webapp/wc...toreId=11151&catalogId=10001&page=Marine-Wire
Remember, you need to figure round-trip wiring distances. Though with a truck you will likely use the frame as the ground so that's not so much of an issue as it is in a fiberglass boat with no frame.
I also like that 300 A/H capacity. You could do that with 3 group 31s or a better yet a pair of 6v L16s, though at a slightly higher cost.

 

[java]

Yes do the biggest reserve you can fit/afford. maybe make the battery tray able to take another battery on down the road if neede, or when you can afford it. Your going to be pushing the limits of the batteries @ 300AH. none of those calculations are prefect either, Id suggest giving a margin of safety for cloudy days.

FWIW, I have 170 AH (only because im working with a factory tiny battery box) and I completely discharge them, running the fridge (4.0amps) and lights (18W) for a couple hours and the heater (bigger RV unit, just the blower from 12V) overnight. I have 200W of solar, and it will charge them back up in a hlaf day of good sun.


And IMO id run the lights off the 12V house battery. AAA's just sound like a pain in the ********, I can imagine they would be dead exactly when you need them.

 

[4x4junkie]

1) If you guys were starting over and building a brand new interior in a totally gutted Sunrader motorhome, would you run wire for 12 volt LED light fixtures or would you go wireless by using self-contained LED light fixtures that use rechargeable AAA batteries? And if the consensus is to run wires for 12 volt LED light fixtures, then is 16 AWG wire okay?

Definitely wire it up for lights. AAAs suck, both for available power (brightnes) and longevity.
For lights, go to Home Depot (or other hardware/home improvement center) and pick up some small low-voltage MR-16 style tracklighting lamps and LED MR16 bulbs. I've found these work well on 12VDC and usually put out a much more pleasant light color than the cold bluish light typical of LEDs sold for camping/RV use (look for ones around 3000°K color temp). Note that some of these lights may emit wide-band radio interference (Philips 10W ones are particularly bad), so if you have 2-way radios operating in the 10-200MHz region (CB/10M, 6M, 2M, MURS, etc.), there's some possibility you may need to do some RFI suppression work on them (installing ferrite chokes, etc.).
16 AWG wire should be fine unless you want to run like 3 or more lamps off the same circuit, then use 14 AWG.

2) Is the main rating battery manufacturers use to show the amp hours typically based on the 20 hour rating?

Yes.

...

Yes, big wire is one of the main things that Handy Bob stresses too. If I go with a 300 amp hour battery bank then realistically I can only tap half of that (150 amp hours), correct? And if that is correct then I'm pretty close to hitting that on the days I might need 134 amp hours.

Like java said, go as big as you can fit/afford. A ~450AH bank can be easily assembled from 4 of the GC batteries you mentioned (two strings of two in parallel). For a 450Ah system you should also have about 550-750W of solar to go with it. This will provide roughly 10% of your AH capacity in charging current (or about 40-50 amps) which is the typical recommendation.

 

[magentawave]

Okay, three people, including you guys, have advised me to blow off AAA powered LED's for wired LED's so thats what I will do and I'll use 14 gauge when I have 3 or more lights on the same circuit.

Like I said previously, to save interior space and get the weight of the batteries even lower, I might build a steel battery rack for underneath that will attach to the frame and sit aft of the differential with a trap door in the Sunraders floor so I can access them. Have you guys seen anything like that on this forum? This is for an 82 Toyota.

I hope to have a list of all the stuff I'm going to need for this done this weekend (solar panels, controller, wires, batteries, etc.) and I was wondering if you guys know anyone that could draw a wiring diagram for me please?


What kind of DC fridge do you have and how many amp hours does your heater blower use?

Yes do the biggest reserve you can fit/afford. maybe make the battery tray able to take another battery on down the road if neede, or when you can afford it. Your going to be pushing the limits of the batteries @ 300AH. none of those calculations are prefect either, Id suggest giving a margin of safety for cloudy days.

FWIW, I have 170 AH (only because im working with a factory tiny battery box) and I completely discharge them, running the fridge (4.0amps) and lights (18W) for a couple hours and the heater (bigger RV unit, just the blower from 12V) overnight. I have 200W of solar, and it will charge them back up in a hlaf day of good sun.

And IMO id run the lights off the 12V house battery. AAA's just sound like a pain in the ********, I can imagine they would be dead exactly when you need them.

The problem I foresee with track lighting is that I'll probably bump my dome into it! I'll check Amazon and eBay for low profile warm light LED fixtures.

Definitely wire it up for lights. AAAs suck, both for available power (brightnes) and longevity.
For lights, go to Home Depot (or other hardware/home improvement center) and pick up some small low-voltage MR-16 style tracklighting lamps and LED MR16 bulbs. I've found these work well on 12VDC and usually put out a much more pleasant light color than the cold bluish light typical of LEDs sold for camping/RV use (look for ones around 3000°K color temp). Note that some of these lights may emit wide-band radio interference (Philips 10W ones are particularly bad), so if you have 2-way radios operating in the 10-200MHz region (CB/10M, 6M, 2M, MURS, etc.), there's some possibility you may need to do some RFI suppression work on them (installing ferrite chokes, etc.).
16 AWG wire should be fine unless you want to run like 3 or more lamps off the same circuit, then use 14 AWG.



Yes.

...


Like java said, go as big as you can fit/afford. A ~450AH bank can be easily assembled from 4 of the GC batteries you mentioned (two strings of two in parallel). For a 450Ah system you should also have about 550-750W of solar to go with it. This will provide roughly 10% of your AH capacity in charging current (or about 40-50 amps) which is the typical recommendation.

 

[4x4junkie]

The problem I foresee with track lighting is that I'll probably bump my dome into it! I'll check Amazon and eBay for low profile warm light LED fixtures.

(that is strange, your reply from 2-20 wasn't showing here yesterday... it still showed I had the last post in the thread )

Anyway, I was thinking just use the fixtures themselves without actually mounting them on a track (modifying them as appropriate, mounting them in a corner, under your cabinets, etc.). They aren't real big. If you can find quality WW LED dome lighting though, then by all means go with that.

I have the batteries in my BII mounted similar to how you describe:


Big thing with mounting them like that is watch so you don't compromise your floor's integrity when you cut the hole in it (I had to frame around mine and also add a 1x1" square tube underneath as an additional crossmember to restore the floor's rigidity, partly because the hole on mine wraps down over the side of a hump). I imagine the floor on your MH is made of plywood or something similar so it'll probably be a little easier to work with.

 

[magentawave]

Hey thanks for posting the photos of your battery storage rack! Since the Sunrader floor is plywood I decided that if I hit something weird it would be too risky to lose my batteries. I'm thinking of building a metal rack like you did but instead of it attaching to the underside of the plywood RV floor I'll connect the front of the rack to this round cross member of the frame thats forward of the axle and the rear of the rack to larger square cross member thats aft of the differential but forward of the spare tire. Not sure how the heck I'm going to do that yet though. Once I decide on the batteries and the number, I was thinking of building a full scale plywood mockup that the welder could use as a model to make one out of steel.

(that is strange, your reply from 2-20 wasn't showing here yesterday... it still showed I had the last post in the thread )

Anyway, I was thinking just use the fixtures themselves without actually mounting them on a track (modifying them as appropriate, mounting them in a corner, under your cabinets, etc.). They aren't real big. If you can find quality WW LED dome lighting though, then by all means go with that.

I have the batteries in my BII mounted similar to how you describe:


Big thing with mounting them like that is watch so you don't compromise your floor's integrity when you cut the hole in it (I had to frame around mine and also add a 1x1" square tube underneath as an additional crossmember to restore the floor's rigidity, partly because the hole on mine wraps down over the side of a hump). I imagine the floor on your MH is made of plywood or something similar so it'll probably be a little easier to work with.

 

[magentawave]

Here is a preliminary wiring diagram for my solar system. I've never done this before so don't doubt its seriously F-ed up, but hey, I have to start somewhere so I don't blow myself up later, right? Right. Those are Crown 6 volt batteries.

 

[4RunAmok]

I don't know if that is your diagram or one you found, so here is a diagram showing how to correctly draw from, or charge into, a parallel battery bank.

This way, you are drawing power from, or sending power to, each battery equally. Drawing power from the leads of just one of the batteries, this battery will experience much more drain than the second battery in the bank, third, and so on, and will require much longer periods to recharge the bank.

 

[magentawave]

I did the diagram myself but I don't know much at all about this stuff which is why I need help. So the way you show the two batteries will work for two 6 volt batteries too?