Solar, lighting and more.

[Vanada]

Panels, MPPT, batteries, fuse box and fan are hooked up! Photos will go on my build thread soon but before I get too excited I want to make sure that the numbers are checking out because I'm a bit worried about the refurb batteries.

I made sure the panels were all working individually by covering two of the three at a time. Seemed decent and I was getting 2 amps off of all 300w in overcast conditions. I don't know if that is good or not. The batteries had been sitting around for a while but connected together they put out 12.7v. When charging in the day the controller read 13.6v. I was away for over a day and just got back at night to find it reading 12.7v again with no draw in that time. Is that normal? I had been putting off learning about batteries properly but now it's all setup I should probably start getting my eye in!

Cheers,
Tom

 

[Vanada]

I'm a bit uncertain about hooking up the battery isolator so I'll outline my plan and perhaps someone can tell me if any of it sounds a bit, y'know... Deathy.

Starter Battery > short 4 gauge wire > Isolator under hood (chassis grounded and piggybacking the ignition somehow) > 8 gauge wire running under the length of vehicle > 50A breaker > more 8 gauge wire > House batteries

My conundrums are these:
- Where should the 50A breaker go? Close to the starter or close to the house battery?
- Do I need any more breakers adding anywhere in there?

Tom

 

[SternWake]

If you take power from engine starter battery for isolator, then a breaker/fuse needs to go on both ends, close to each battery.

if you instead take power from alternator(+) stud, then only one fuse is required close to house/Aux battery, and more alternator amps will also get to house battery. Win Win.

How hard is it to reach back of alternator and stack another ring terminal on output stud(+)? If easy, then do it.

 

[Vanada]

If you take power from engine starter battery for isolator, then a breaker/fuse needs to go on both ends, close to each battery.

if you instead take power from alternator(+) stud, then only one fuse is required close to house/Aux battery, and more alternator amps will also get to house battery.  Win Win.

How hard is it to reach back of alternator and stack another ring terminal on output stud(+)?  If easy, then do it.

Sweet, I'll check it out when I get the chance. Are the wire gauges are okay though? I don't understand what's driving the number of amps passing through / from the isolator in order to calculate them. Also, if powering directly off the alternator would I still need to tap into the ignition as a switch?

 

[Vanada]

Couple quick things worth noting: The isolator is a 200A solenoid type. I am currently using cheap thermal breakers from Amazon so if those are not suitable / potentially dangerous for this application it would be good to know now

 

[Vanada]

If you take power from engine starter battery for isolator, then a breaker/fuse needs to go on both ends, close to each battery.

if you instead take power from alternator(+) stud, then only one fuse is required close to house/Aux battery, and more alternator amps will also get to house battery.  Win Win.

How hard is it to reach back of alternator and stack another ring terminal on output stud(+)?  If easy, then do it.

Took a look and the alternator seemed pretty buried until I watched a video on doing a replacement and it's actually not too bad. Just have to move the airbox and coolant reservoir out the way then unbolt the alternator.

I was just trying to research the battery isolator stuff again and some part of it just isn't clicking. Either I have it right in my head and all is well or I have it very wrong and am about to rig some total nonsense.

I want to wire directly to the alternator as you mentioned. Could you please describe that in a little more detail? I'm envisaging one cable from alternator to solenoid, to house battery via a breaker. Isolator grounded and connected to a true ignition source off the two smaller studs... Right? I guess I'm just struggling to understand the flow of energy and the purpose of the isolator in that scenario.

Thanks again by the way SternWake. Your posts have been invaluable!

 

[SternWake]

I want to wire directly to the alternator as you mentioned. Could you please describe that in a little more detail? I'm envisaging one cable from alternator to solenoid, to house battery via a breaker. Isolator grounded and connected to a true ignition source off the two smaller studs... Right? I guess I'm just struggling to understand the flow of energy and the purpose of the isolator in that scenario.

It is as you envision, the alternator will already have a thick wire coming off a main stud which is (+) . 
One will stack another ring terminal on this stud, 4 AWG, and this goes to solenoid, then breaker, then house battery (+).

If the Solenoiid has 4 terminals, 2 big, two small, then the solenoid does not heve to be grounded, as one of the smaller studs will be required to be grounded.  the 4 terminal Solenoid does not have to be mounted on firewall, nor close to alternator.  It can be on the outside of your battery box right next to the breaker if you want.  Whatever is easiest and can make for the shorter circuit path.

When the solenoid is not triggered by 12v, then there is no connection between house battery and alternator.  Since the alternator is also directly connected by the existing original factory wiring to engine baqttery, when solenoid is not powered/triggered, then the house battery and engine battery are isolated from each other.

The + is half the circuit, the ground - is the other half, but the ground need not be switched.  The house batteries can be grounded to frame, or grounded to engine battery, or to alternator, or to engine.  My opinion it is best to ground house battery to alternator (-) stud or mounting bolt as this bypasses the frame grounds or existing ground path.  it will increase amps into depleted house batteries and eliminate a possible future issue when the frame grounds inevitably develop more resitance with age and corrosion and heating cycles.

Stacking another ring terminal on the alternator (+) stud is not always so easy.  Some studs are surprisingly small and want to fight a secondary ring terminal stacked on the original ring terminal.

Make sure the additional cable can flex with the engine, and cannot chafe, and does not hang the whole weight of the cable on the alternator (+) stud.

 

[Vanada]

It is as you envision, the alternator will already have a thick wire coming off a main stud which is (+) . 
One will stack another ring terminal on this stud, 4 AWG, and this goes to solenoid, then breaker, then house battery (+).

If the Solenoiid has 4 terminals, 2 big, two small, then the solenoid does not heve to be grounded, as one of the smaller studs will be required to be grounded.  the 4 terminal Solenoid does not have to be mounted on firewall, nor close to alternator.  It can be on the outside of your battery box right next to the breaker if you want.  Whatever is easiest and can make for the shorter circuit path.

When the solenoid is not triggered by 12v, then there is no connection between house battery and alternator.  Since the alternator is also directly connected by the existing original factory wiring to engine baqttery, when solenoid is not powered/triggered, then the house battery and engine battery are isolated from each other.

The + is half the circuit, the ground - is the other half, but the ground need not be switched.  The house batteries can be grounded to frame, or grounded to engine battery, or to alternator, or to engine.  My opinion it is best to ground house battery to alternator (-) stud or mounting bolt as this bypasses the frame grounds or existing ground path.  it will increase amps into depleted house batteries and eliminate a possible future issue when the frame grounds inevitably develop more resitance with age and corrosion and heating cycles.

Stacking another ring terminal on the alternator (+) stud is not always so easy.  Some studs are surprisingly small and want to fight a secondary ring terminal stacked on the original ring terminal.

Make sure the additional cable can flex with the engine, and cannot chafe, and does not hang the whole weight of the cable on the alternator (+) stud.

Cheers! Although each item is only prompting more questions...

- So, solenoid grounds to chassis using smaller gauge wire. Yes?
- If I understand correctly the alternator is acting as a switch of sorts so a 12v true ignition source wire off one of the small terminals is not necessary? Or do I still need that as well?
- I hadn't planned for any way to ground my house batteries. Is this a necessary step I somehow missed? I have a negative cable going to the DC load fuse block but nothing to the chassis in any way. I was going to ground the inverter to chassis as well using 8 AWG having read the manual.
- So I can run a short cable to chassis by the battery box inside the cargo bay or another ~20' 4 AWG negative cable back to the alternator, the latter being more future-proofed and better for charging?

I've been flat out lately and am fully mentally exhausted so apologies if some of that sounds a bit dumb. I feel like a wet sponge in an ocean of knowledge right now but I'll get it eventually!

 

[SternWake]

Yes to charge house battery via the alternator, they must be grounded to alternator either directly, or to the frame. I explained earlier the advanages of going directly to alternator mounting bolt with the ground, but one can certainly just ground nearby the battery box to any thick metal.

The solenoid only draws one amp or so to hold the contacts together, the wire for the trigger circuit does not have to be very thick as 1 amp is not much current. One of the smaller terminals on the solenoid is for ground, the other for the (+) hot that is switched by the ignition when engine is on. Does not matter which is which on the trigger circuit.

The alternator is not a switch, the solenoid is. it is a heavy duty switch that uses an electromagent to hold the main contacts together under pressure for good electric flow/minimal heating

 

[Vanada]

Yes to charge house battery via the alternator, they must be grounded to alternator either directly, or  to the frame.  I explained earlier the advanages of going directly to alternator mounting bolt with the ground, but one can certainly just ground nearby the battery box to any thick metal.

The solenoid only draws one amp or so to hold the contacts together, the wire for the trigger circuit does not have to be very thick as 1 amp is not much current.  One of the smaller terminals on the solenoid is for ground, the other for the (+) hot that is switched by the ignition when engine is on.  Does not matter which is which on the trigger circuit.

The alternator is not a switch, the solenoid is. it is a heavy duty switch that uses an electromagent to hold the main contacts together under pressure for good electric flow/minimal heating

Got it! I drew up a real quick diagram (attached) to verify everything. The low-opacity wires are just to indicate their passing through the floor / underneath the vehicle. Let me know if anything is unclear or incorrect

 

[SternWake]

Looks good. with 4 AWG cable you can run a bigger circuit breaker or fuse.

The following chart says 4awg is good for 136 amps inside engine compartment and 160 outside of it:

http://www.genuinedealz.com/voltage-drop-calculator

I have a '140 amp' breaker that recently tripped after less than 5 minutes at 70 to 90 amps. it could have blown the diodes in my alternator, as my original existing parallel charge path wiring was disconnected.

Wish I bought Bussman brand rather than saving 12$ and buying 'Absolute brand' through amazon.

You can run the 12v trigger circuit through an illuminated switch on your dashboard for additional control of when house battery charges.

Fuse taps
Mini fuse:
https://www.amazon.com/WirthCo-30800-Battery-Doctor-Fuses/dp/B000CQDRTI

ATC/ATO

https://www.amazon.com/s/ref=nb_sb_noss_1?url=search-alias=automotive&field-keywords=ato+fuse+tap


Glass fuse:

https://www.amazon.com/Wirthco-3020...qid=1489384347&sr=1-1&keywords=glass+fuse+tap

 

[Vanada]

Great! I have a spare 80A breaker so I can step it up to that for the time being.

 

[SternWake]

What is your alternator rated at?

Your battery bank is 2 6v GC-2s?

There is a possibility that when the batteries are well depleted, and your engine is spinning at 2k rpm+ on the highway, that the 80 amp circuit breaker might trip.  As this is a parallel circuit, the factory wiring will prevent a total load dump which could fry diodes in alternator.  This is another reason to take power, not from engine battery, but from alternator (+) stud.

I was unfortunately and foolishly surprised my bargain '140' amp breaker tripped at much less current than that.

They are thermal breakers, and it appears that lesser amperages applied for longer can heat them enough to break well below their rating.  hopefully a good brand like Bussman would be better than the junk I use, but both operate on same principle and 60 amps for an hour might trip it.

No big deal, flip the switch and charging resumes, but you might find you arrive at a location after a longer drive only to find the breaker tripped and batteries not charged as much as desired.  A dashboard voltmeter whose voltage sense line is on the house battery would make this  obvious, and also be a good tool for learning.

https://www.amazon.com/bayite-wires...d=1489431420&sr=8-1&keywords=3+wire+voltmeter

The voltmeters above can be calibrated, and have a dedicated ( white) voltage sense wire that ideally would run back to house battery.  As it carries very little current it can be 22 to 28 awg wire.  You can have voltmeter powered by same fuse which triggers solenoid so it only comes on when key is on.

Just an option, not a necessity, but if you have not run the cabling yet, you could tape some Zip wire to the 4awg and run both at same time as it would be a lot less effort and come out cleaner, than running it later, should you desire.

https://www.amazon.com/20ga-Red-Bla...=UTF8&qid=1489431612&sr=1-2&keywords=zip+wire

it would be even more accurate if voltmeter's ground was run through the 2 wire zipwire along with voltage sense, then the red power on wire could goto the trigger circuit's fuse tap.

Hope this does not confuse.

 

[Vanada]

What is your alternator rated at?

Your battery bank is 2 6v GC-2s?

There is a possibility that when the batteries are well depleted, and your engine is spinning at 2k rpm+ on the highway, that the 80 amp circuit breaker might trip.  As this is a parallel circuit, the factory wiring will prevent a total load dump which could fry diodes in alternator.  This is another reason to take power, not from engine battery, but from alternator (+) stud.

I was unfortunately and foolishly surprised my bargain '140' amp breaker tripped at much less current than that.

They are thermal breakers, and it appears that lesser amperages applied for longer can heat them enough to break well below their rating.  hopefully a good brand like Bussman would be better than the junk I use, but both operate on same principle and 60 amps for an hour might trip it.

No big deal, flip the switch and charging resumes, but you might find you arrive at a location after a longer drive only to find the breaker tripped and batteries not charged as much as desired.  A dashboard voltmeter whose voltage sense line is on the house battery would make this  obvious, and also be a good tool for learning.

https://www.amazon.com/bayite-wires...d=1489431420&sr=8-1&keywords=3+wire+voltmeter

The voltmeters above can be calibrated, and have a dedicated ( white) voltage sense wire that ideally would run back to house battery.  As it carries very little current it can be 22 to 28 awg wire.  You can have voltmeter powered by same fuse which triggers solenoid so it only comes on when key is on.

Just an option, not a necessity, but if you have not run the cabling yet, you could tape some Zip wire to the 4awg and run both at same time as it would be a lot less effort and come out cleaner, than running it later, should you desire.

https://www.amazon.com/20ga-Red-Bla...=UTF8&qid=1489431612&sr=1-2&keywords=zip+wire

it would be even more accurate if voltmeter's ground was run through the 2 wire zipwire along with voltage sense, then the red power on wire could goto the trigger circuit's fuse tap.

Hope this does not confuse.

Sorry for not responding sooner. Yes, two Trojan T-105's (Or so I'm told. They're the non-branded black ones but in every other sense they are cosmetically the same). Will have to find out the alternator output.

I think I'll consider setting up a voltmeter at some point but I did lose you a bit at the end there... I think I have a rough idea though: 
Battery pos and neg connect to the zip wire which runs to the front of the vehicle, the black and white wires on the voltmeter connect to the zip wire (or the aux DC fuse block for that matter) and the red wire on the voltmeter can go on a t-connector or similar to the trigger wire which is being used by the solenoid so that it is powered when the vehicle is running. I've been trying to keep the cab and cargo bay free of excess wires, hence wanting to run these ones beneath the vehicle. I did however just find out that running wires from the engine bay into the cab might not be as hard as I'd imagined.

The mini fuse tap I bought is 16AWG for 10A so I guess that will be enough for the trigger wire. I have a trailer harness I'm willing to cannibalize for the ground wire but I'm not sure on the gauges (it's at home, I'm not. Will check later). What's the smallest sensible gauge for the solenoid ground? I could even use some spare 8 gauge if needed.

 

[Vanada]

Update: The alternator is 105A (Glad I had a picture of the RPO code plate!)

 

[SternWake]

The solenoid trigger wire only needs to pass about 1 amp.  to hold solenoid contacts closed, so 18 AWG is fine.  8awg for the solenoid ground would be a waste and extreme overkill.  No alternator charging current goes through solenoid ground.  


The Zipwire recommendation, is only for the optional 3 wire voltmeter.  The voltmeter's red wire is the power on wire, and this can be powered by same circuit as trigger circuit, or another circuit of your choice.

The Zipwire would mate with black and white voltmeter wires and  goto house battery + and -.  This voltmeter would then be much more accurate as to house battery voltage than if the Voltmeter took voltage sense reading from nearby wiring.

Again, the 3 wire voltmeter with Zipwire voltage sense lines to house battery is optional, not necessary.  Seeing house battery voltage slowly climb when driving is enlightening as to house battery state of charge, and also for seeing when the vehicle's voltage regulator declares that 13.7v is fine and dandy and charging slows by at least 1/3, compared to higher voltages.

Many people use the dashboard Ciggy plug and plug a voltmeter into that, but the reading there can be quite different than voltage at the house battery terminals.  The Zipwire for voltmeter sense, would be easiest to run at the same time you run the (+) cable for the alternator charge path to house battery, which is why I brought it up.  It could always be done later, if desired, or not at all.

 

[Vanada]

Great! If I can get hold of a voltmeter soon enough I'll do that.

If 8AWG for solenoid ground is overkill, would 16AWG be fine? I suppose the smarter thing for me to do is comprehend the ground so that I know what current might actually flow through it and I can calculate that myself.

 

[SternWake]

16 AWG should be fine for the solenoid trigger ground, as they rarely draw more than 1 amp.  If mounting solenoid  on vehicle firewall most simply run a short length from Smaller solenoid terminal to the mounting bolt.

The only time I envision too small of wire gauge triggering a solenoid is if the wire distance is huge.

I'd likely use 12 or 10AWG as I Don't generally purchase thinner wire.  16 or 18AWG I salvage for powercords on failed AC devices.

The 3 wire voltmeter is desirable, as the voltage sensing at battery terminals is desirable.  Just any old  2 wire voltmeter should then be attached right to battery terminals rather than tapped into a nearby convenient circuit.  This 2 wire voltmeter right to battery terminals, would then need to be switched, or it would always be illuminated.  The 3 wire can have its ground and voltage sense lines run to battery terminals then be turned on and off with ignition key, like the solenoid is.

The 3 wire voltmeter, 5 for 10$ I linked previously, can be calibrated too.  They are quite small.  I recommend red as the green is hideously bright.  i used 3 layers of 35% window tint to tame the green ones  down, and one on the red.

The bigger green 0.00 display on top is My Ammeter.  it is also a voltmeter, but I have mine displaying only Amperage.  It has a toggle button on back to choose amps, volts, or both.

https://www.amazon.com/bayite-Digit...490216845&sr=8-1&keywords=hall+effect+ammeter

This ammeter however has no dedicated voltage sense line and would read voltage at my fuse I tapped to power it, the other 2 voltmeters, and my aftermarket tachometer.  Turning the blower motor on high would likely reduce its reading by 0.5 volts, but actual battery voltage would not change 0.05v.

 

[Vanada]

Hey all! Things have come a long way for my build as I've been working flat out (update to my conversion thread coming soon!)

I do however have one concern to air. A few months ago I did a mediocre job of securing the cables underneath the solar panels before installing them, during which I was somewhat up against the clock. Now I have three panels secured to the roof using VHB, the brackets are covered in Sikaflex and the mounting bolts between the brackets and the panels are inaccessible. It's safe to say they're not going anywhere for a while, but some of the cabling and MC4 connectors are in contact with the roof underneath. I just want to know what my concerns should be and how big a deal this actually is.

Cheers!
Tom

 

[highdesertranger]

first it will rub the paint off then after a unknown number of years it will rub through the insulation on the wires. highdesertranger