solar + batteris

[Slownsy]

Hi all.
I am in proses of installing solar on my FW I planed on installing 2
/150W panels but made mistake when ordering and ordered 2 lots of 2 so have got 4/150W panels, also got 30' of 8AVG cable to split to my trimetric sc 2030 controller and 2030 monitor. cable is rated for 600v so is this a little to small or will it be ok. Al panels max 36A at 16' to controller .7219v drop or 4.0108% drop.2 260A 6V Crown Batteries what are your thoughts.
Frank.

[time2roll]

#8 is fine

[BFL13]

Slownsy wrote:
Where is Florida to Alaska, controler to batteries will be one cable 2' one 5' as plased end for end and allowing for 2 more later if we want them. Do I instal all 4 panels or leave it at 3.
Frank

Good question! 🙂 Ok, IMO, leave two panels on your 2030 and get a second controller for the other two and run both controllers in parallel on the same battery bank. Needs a bit of extra wire, but so what. ( I recommend the Solar30 controller for its built in read-out display of amps and volts for about $35 on eBay)

I have run two controllers with the same voltages on the same bank, and they add their amps no problem.

[pianotuna]

Hi Frank,

You need some overhead on the controller. 450 watts is really pushing the envelope on a 30 amp controller.

Good design for a 30 amp suggests a maximum of 24 amps of input. With 450 watts, under ideal conditions you may be approaching 35 amps.

I would upgrade to a 45 amp controller, or else just use 2 panels.

[Slownsy]

Where is Florida to Alaska, controler to batteries will be one cable 2' one 5' as plased end for end and allowing for 2 more later if we want them. Do I instal all 4 panels or leave it at 3.
Frank

[BFL13]

Slownsy wrote:
I have got what I have which is a great controler and monitor with temp censer, I do not intend to change controler, the question was about the cable 8AVG if it wood be ok or not, if panels sitting flat won't achive ther full capasety of 9A each and som Loss in cable will stil supply the controler with 30a and then larger cable 2AVG or larger from controler to batteries. Thanks.
Frank.

A panel will do its Isc (ignore the lower amp Imp for MPPT) at STC when the panel is aimed at the sun. So how much less you get when the panel is flat depends on how high the sun gets where you are at what time of year.

You can be far enough South in the summer that your flat panel will hit its full Isc rating. So "it depends". Provide some info on where and when before anybody can answer that question.

[westend]

OP states he has two 6V Crown batteries @260 AH. The length of the run from modules to controller is 16'. He does not say what length of run is from the controller to batteries.
If it was me, I'd use #10 MCA cable from the modules to a combiner box on the roof and then run AWG 4 from the box to the controller (interrupting it with a circuit breaker mounted close to the controller). For the controller to batteries, I'd use the same AWG 4, depending on the length of run to the batteries. I tend to use larger wire than most but I reasoning is that I'd rather pay a few dollars more for wire, initially, than give up solar harvest eternally.

[NinerBikes]

How many amp hours of battery do you have?

Very important information before a better answer for amount of amps and # of panels and combined charging amps necessary.

How many amp/hrs do you use in a normal day?

[Slownsy]

I have got what I have which is a great controler and monitor with temp censer, I do not intend to change controler, the question was about the cable 8AVG if it wood be ok or not, if panels sitting flat won't achive ther full capasety of 9A each and som Loss in cable will stil supply the controler with 30a and then larger cable 2AVG or larger from controler to batteries. Thanks.
Frank.

[Almot]

smkettner wrote:
The beauty of the Trimetric 2030 is that it ties into the battery monitor to better control the charge rate.

I don't understand about this being tied into monitor for better control. If there is a sun, any decent controller will do a good job of controlling the charge rate without being tied into battery monitor. When there is no sun, you may try hypnotizing the monitor all you want, but controller won't do a squat.

A PWM controller like Xantrex 40 or Morningstar 45 should be adequate with 4 panels. With battery monitor, yes - mostly to control the consumption side, because this is the only thing that you have any real control over.

One thing I hate more than running a generator, is killing a battery because of insufficient solar wattage. The OP plans to flat-mount them, so with 2 panels there won't be too much juice.
Only people that got their panels 10-12 years ago - and paid 10 times more than it costs today - carry mere 300W on a 5-er of that size. Today most installs are few 24V panels and MPPT controller for total 700-800W - I think I know one such guy and I think he is quite satisfied ;). Simple series wiring with MC4 AWG 10.

[Slownsy]

Ok tanks all yes I ment 4/150Watt panels, only planed on getting 2 but as I now have the 4 and the room for them, someone mentinned that the trimatik wood handle the extre load ok as they will be mounted flat and properly newer reach ther full potential, they are Renogy 150 W mono crystalline.
I can go to larger wier and stay with 3 panels if this what most recommend and try to sell last panel.
Frank.

[time2roll]

The beauty of the Trimetric 2030 is that it ties into the battery monitor to better control the charge rate. Unless Trimetric makes a larger controller I would stick with what you have and use fewer panels.

[Almot]

He mixed up volts and watts, I think.

Panels with PWM controller need parallel wiring, yes.

A 5-er - if FW means 5-er - has enough space on the roof for all 4 panels. You may keep all 4, and get a controller with higher capacity, around 40A. Shouldn't cost more than $120, for a good one. With 4 panels you should probably get AWG 6 cable, do you math.

[time2roll]

Don't connect more than 30 amps (Isc rating) to that controller. Probably just 2 or 3 panels only. Connect panels in parallel not series.

[2oldman]

I think you're getting your watts and volts mixed up. Got a link?

[jrnymn7]

X2 on a minimum of a 45a controller, IF running all 4 panels together.

30' of 8ga /2 = 15' run. In parallel, at 36a, that's a voltage drop of 0.7v, almost 6%... nasty. You will need at least 4ga, and 2ga would be better. But that's all with a pwm controller.

If you wire them in series/parallel, and go 45-60a mppt, 15' at 18a will result in a voltage drop of 0.35v (almost 3%) using your 8ga wire... 6ga would be better.

Another option is to go with two separate systems... either two 30a pwm's with panels in parallel, (resulting in the same numbers as directly above)... or two 30a mppt's with panels in series, (resulting in half the voltage drop). Provided the two controllers are set to the same voltage, they will combine their amperages equally.

How many 6v batteries do you have, and what is their combined total Ah capacity?