Which batteries do I REALLY need?

[electricalidiot]

Hi-
I'm new here and despite years of being around it, I am just stupid with the details of solar energy. I run a small off-grid field station in Northwest Mexico. I inherited a system that has 200 watts of solarex panels, a Trace c12 charge controller, a tri-metric, and a prowatt 1500 inverter. The batteries have always been an issue. I think we started with 4 6v in series and parallel. They usually last about 3 seasons. We have to shut everything down for 6 months during the summer is the reason why. We bought 4 12v here in mexico last year (4th set of batteries for the system), and I could find absolutely zero info on amp hours or anything (no there aren't any reputable dealers here). I am thinking of getting some good batteries by going up to Tucson. My question is What should I get to get he most power out of our 200 watts? I need to be spoken down to here, I'm really slow. I just need to know what I need and how to wire them. I don't do well with hypotheticals.

At night we run about 4-5 lights (all AC) mostly LED. only at night. in the day we charge tools, laptops, phones etc.

Thanks for your help!

[russ]

Hi electrical (or would you prefer idiot) Welcome to Solar Panel Talk!

Russ

[Sunny Solar]

Electrical person . why you running AC .LEDs ? you better off staying on DC for the lights and charging your devices. Much simpler solution... Dont use an inverter unless you really have no DC option.

[Wy_White_Wolf]

Hi-
I'm new here and despite years of being around it, I am just stupid with the details of solar energy. I run a small off-grid field station in Northwest Mexico. I inherited a system that has 200 watts of solarex panels, a Trace c12 charge controller, a tri-metric, and a prowatt 1500 inverter. The batteries have always been an issue. I think we started with 4 6v in series and parallel. They usually last about 3 seasons. We have to shut everything down for 6 months during the summer is the reason why. We bought 4 12v here in mexico last year (4th set of batteries for the system), and I could find absolutely zero info on amp hours or anything (no there aren't any reputable dealers here). I am thinking of getting some good batteries by going up to Tucson. My question is What should I get to get he most power out of our 200 watts? I need to be spoken down to here, I'm really slow. I just need to know what I need and how to wire them. I don't do well with hypotheticals.

At night we run about 4-5 lights (all AC) mostly LED. only at night. in the day we charge tools, laptops, phones etc.

Thanks for your help!

Well you system is way out of balance.

You have 200w array, 4 - 12v batteries would be 300 to 400Ah at 12v, and a 1500W inverter.

Your array is to small to properly charge the batteries and the batteries are too small for the inverter.

The array can only support 2 of those batteries with the PWM charge controller and the 2 batteries then could only support about a 200w inverter.

You really need to start over with doing a full evaluation of your loads to see what you need. As suggested by the loads you listed you should beable to run a full dc system and not need an inverter.

It would help if you could find a way to keep the batteries on a float charge when the system is shut down for the summer.

WWW

[Sunking]

Ditto with only 200 watt panel and a PWM controller you can barely support a small 12 volt battery and a 200 watt inverter.

[Sunny Solar]

Electrical person your 1500 w inverter is probably self consuming 1a. thats 24ahr or 288whr .. You are wasting about 1 and a half hrs of sunlight on your 200w panel every day just to feed your inverters self needs..

[Mike90250]

1) you need more solar PV, your loads are too much, and you are most likely deficit charging the batteries, which die soon.

2) Are you stuck on 12V ? Can you go 24v and use a nice small sine wave inverter ?

3) Do you have a generator to charge the batteries on cloudy days, or do you let them sit and sulfate

4) Perform a load analysis as to what you NEED, opposed to what you think you use.

5) design your next battery bank, with 6v, 4v or 2v cells, to get the capacity you need, not by paralleling cells that are too small. If 6v, 200ah golf cart batteries are too small, then go with 4v,350ah. Just one series string.

6) The morningstar SureSine 300 is a good, sturdy and efficient 12V inverter, if you insist on using 120VAC LEDS instead of nice directional 8-30V LEDs
https://www.wiredco.com/10_LED_SMT_S...rmwhiteled.htm

[electricalidiot]

Thanks!

THANK YOU!!
I must say based on previous experience on this type and other message boards, you are all wonderfully nice and understanding. It reaffirms my hope in the internets. I am very grateful, it can be hard to get straight answers at times, and no one called me names or told me how stupid I am. Seriously, you all should win some sort of internet award.
Here is a (possibly fun) >two parter for you: What would you EXACTLY do in this case? assuming (without exact load info) we would want to keep up the loads we have (5 lights at night, charging a lot during the day) and add a little, what should we do? Keep some of this system or start over? I can give a detailed list of probable loads/usage if you think it necessary.
The 5-7 months with nothing happening and packing everything up is a bugger. If the panels are out there is a high possibility of vandalism or theft. last summer we left an old 80 watt panel bolted to the roof (not at an angle) and that helped a little, but there is no draw.

Thanks so much! beers for all if you get to southern Sonora Mexico.

Anyone know about those all inclusive kits on amazon?

thanks

-Adam

[Mike90250]

If it was my system to restore, I'd add matching panels in parallel (for 400w of PV) (30A @ 12 V)

I'd get a Morningstar SureSine 300 watt inverter (12v)

I'd use 4, 6v - 200ah golf cart batteries wired series/parallel on the diagonal

I'd use the little disc LED lights @ 12Vdc and use the inverter to power up an outlet strip for the AC chargers for the gizmos.

You are deficit charging the batteries, which is why they die in a year, so you need more PV. 400w is about the minimum you can get by with. Golf cart batteries should last you 2 years in this application, if you don't pull them down too much.

It's a small system, it can't do a whole lot.