controller use

temmons

first off lets get it out there..... I don't know anything about solar. I am now learning to try and make less mistakes on my Freedom 40 Ketch.
I have read quite a bit but have a few questions and hope for a little help... that being said::::

I have two separate (4 each 6v golf cart) banks. until I get to the boat in Maryland I cant tell you if they are flooded, deep cycle or Nickel-cadmium

I understand I will collect all the voltage/amp hrs/watts from all the items on my boat to figure out power needed from my panels and controller.

1. if I use 4 100watt panels can I use One MPPT controller to power both banks or should I use 2 separate systems IE 2panels- 1 controller to each bank?
2. why would you choose a 15v controller over a 30v controller?

WillBkool

Re: controller use

I'm fairly new as well, but I've been studying this stuff for a while now.

1. Yes, you need 2 charge controllers to charge 2 separate battery banks.
2. Controllers usually come in 12v, 24v or 48v. It will depend on the voltage of your battery bank. If you have your 4 6v batteries in series, that would be 24 volts, and would be better than paralleling them, which would give more current, but can add some additional problems.

Depending on the amp-hours of your battery banks, I don't think dividing up your 4 100w panels into 2 panels to each bank will give you enough charge amperage.

You really need to specify how your batteries are set-up, series for 24v, or paralleled for 12v, and the amp hours per battery.

Hopefully one of the big dawgs will come and answer your questions better than me.

temmons

Re: controller use

thanks, i'll check on a few things and re-post

ggunn

Re: controller use

WillBkool wrote: »

I'm fairly new as well, but I've been studying this stuff for a while now.

1. Yes, you need 2 charge controllers to charge 2 separate battery banks.

Not if they are connected in parallel servicing the same loads. But then they wouldn't be separate, would they?

Cariboocoot

Re: controller use

temmons wrote: »

first off lets get it out there..... I don't know anything about solar. I am now learning to try and make less mistakes on my Freedom 40 Ketch.
I have read quite a bit but have a few questions and hope for a little help... that being said::::

I have two separate (4 each 6v golf cart) banks. until I get to the boat in Maryland I cant tell you if they are flooded, deep cycle or Nickel-cadmium

I understand I will collect all the voltage/amp hrs/watts from all the items on my boat to figure out power needed from my panels and controller.

1. if I use 4 100watt panels can I use One MPPT controller to power both banks or should I use 2 separate systems IE 2panels- 1 controller to each bank?
2. why would you choose a 15v controller over a 30v controller?

Welcome to the forum.

Golf cart batteries tend to be deep cycle flooded cells of 220 Amp hours @ 6 Volts. It is highly unlikely they will be NiCads. If these are two separate banks you can use either two separate controllers or one dual controller like this: http://www.solar-electric.com/modubachco25.html Note that it requires they have common negative.

Four 100 Watt panels will produce approximately 22 Amps, which is sufficient for charging one set of those batteries but not two together under typical usage. Although the aforementioned controller would be able to maintain both fairly easily. If you have an alternate charge source such as engine, generator, or shore power it will be simple. Also consider what the consequences are if either bank should not be charged.

There's no such thing as a "15v" or "30v" charge controller. In electrical terms "v" or "V" stands for Volts, and controllers are rated by their Amperage. So you would have 15 Amp or 30 Amp. The size has to be able to handle the expected current, as in the above example being 25 Amp and the current from the panels expected to be 22 Amps.

The first thing you should sort out is whether or not you have/need two separate banks and what capacity there is. After that it will not be difficult to ascertain how much panel and what controller you require.

Panamretiree

Re: controller use

A good manual on boat electrics is: Boatowner's Mechanical and Electrical Manual: How to Maintain, Repair, and Improve Your Boat's Essential Systems by Nigel Calder. Goes through all issues that you can be confronted with, including solar, wind and hydro power. Has considerable information on grounding and bonding in a boat. Approximately $36.00 on Amazon.com.

Cheers