Follow up Solar Question

[Katdaddy]

I bought a 130 watt solar suitcase lase year for our trips to the mountains, where we have no hookups. It came with a cheap PWM charge controller and alligator clips to connect to the batteries. Used it on our Fall trip and it worked great. On a previous question someone recommended upgrading to a better charge controller and mounting it inside the camper, which I am in the process of doing. In researching the install I have watched countless how to videos. With the suitcase as it stands I just hook the alligator clips to the battery and go. All of the how to videos say I need breakers and shut off switches and fuses. So, what is different between the two? I don't have a lot of space in my battery compartment to mount all of the devices that I see recommended. What do I really NEED? As always all help appreciated.

[PerryB67]

A year ago we purchased a Renogy 100 watt suitcase. From talking to other suitcase users the wires will be too short to reach sunlight. We have three 15' 10 gauge Zamp cables with SAE plugs. Renogy provided us the proper SAE adapters for our portable.

I thought I'd never use 45' of cable until two months ago in Chiricahua National Monument. We were there for 7 days in cold weather. The furnace blower is our biggest user, and despite 220 amps (110 useable) we would have killed the batteries without 45' of cable.

When running 45' of 10g cable you want the controller inside the camper, as close to the batteries as possible. 18 volts can get by on a smaller wire than 12 volts.

We installed a Victron 110/20 controller with an SAE port on the outside of the camper leading to the controller. Between the batteries and controller I installed a 20 amp fuse that can also double as a disconnect.

Enjoy,

Perry

[Katdaddy]

BFL13 wrote:
Besides the controller's spec for connection sequence for whatever reason to do with that controller, any "12/24" controller wants you to connect to the battery first so it can "see" whether your system is 12v or 24v before it is connected to the array

Yep! I learned this the hard way. I did it backwards and the controller was reading for 24v. I thought I had torn it up right off the bat.

[BFL13]

Besides the controller's spec for connection sequence for whatever reason to do with that controller, any "12/24" controller wants you to connect to the battery first so it can "see" whether your system is 12v or 24v before it is connected to the array

[Almot]

jaycocreek wrote:
I have two 100 watt portable panels without a controller connected...I installed a Renogy 30 amp controller in my camper and did the wiring so when I set the panels out all I have to do is connect them via an Anderson connector..i don't keep the controller hooked to the battery 24/7,only when I'm going to use it.

Renogy MPPT specifically warns: Connect battery terminals to the charge controller BEFORE connecting the solar panel(s) to the charge controller. NEVER connect solar panels to charge controller until the battery is connected. (caps are theirs).

Renogy PWM has no such warning but the connecting procedure goes #1) Connect controller to battery, and then #2) Connect panels to controller.

Leaving controller permanently connected to battery is the safest as this excludes the user's error. Except for (maybe) when you have it in longterm storage with no sun and are concerned about tiny idle draw on the battery.

[Johnny_G1]

jaycocreek wrote:
I have two 100 watt portable panels without a controller connected...I installed a Renogy 30 amp controller in my camper and did the wiring so when I set the panels out all I have to do is connect them via an Anderson connector..i don't keep the controller hooked to the battery 24/7,only when I'm going to use it.

Don't hurt to leave controller hook to battery all the time, had the one in the MH hooked up for 18 yrs, never hurt it untill one battery went out.

[pianotuna]

Katdaddy wrote:

pianotuna wrote:
Katdaddy,

Permanently connect the charge controller to the battery bank with a fuse close to the battery. The rest is unnecessary at 130 watts.

I've read some conflicting information on that. What size fuse should I use.

The first consideration is wire size. Size the fuse to the capacity of the wire.

[jaycocreek]

I have two 100 watt portable panels without a controller connected...I installed a Renogy 30 amp controller in my camper and did the wiring so when I set the panels out all I have to do is connect them via an Anderson connector..i don't keep the controller hooked to the battery 24/7,only when I'm going to use it.

[red31]

I'd fuse a 20A CC with a 20A fuse! or a 40A CC with a 40A fuse.
wires sized bigger than the fuse.

[Katdaddy]

pianotuna wrote:
Katdaddy,

Permanently connect the charge controller to the battery bank with a fuse close to the battery. The rest is unnecessary at 130 watts.

I've read some conflicting information on that. What size fuse should I use.

[Katdaddy]

BFL13 wrote:
Some controllers don't mind and others do (eg Morningstar minds) when you disconnect from battery you are supposed to disconnect the panel from the controller first. You can't do that with the controller on the back of the panel, so it must be one of those that does not mind.

The new controller might mind, don't know. In case it does, you should have a switch in the panel to controller wiring so you can do it all in the right sequence.

I am also installing an SAE plug to bring the solar into the camper.

[BFL13]

Some controllers don't mind and others do (eg Morningstar minds) when you disconnect from battery you are supposed to disconnect the panel from the controller first. You can't do that with the controller on the back of the panel, so it must be one of those that does not mind.

The new controller might mind, don't know. In case it does, you should have a switch in the panel to controller wiring so you can do it all in the right sequence.

[pianotuna]

Katdaddy,

Permanently connect the charge controller to the battery bank with a fuse close to the battery. The rest is unnecessary at 130 watts.

[Katdaddy]

Thanks for the replies. I have purchased a Rich Solar MPPT charge controller and plan to mount it close to the batteries. I was wondering if all of the recommended disconnects and fuses or breakers were really needed, as I have none with the current setup and it worked just fine.

[Sandia_Man]

We have a solar suitcase we implement from time to time to supplement the solar panels we have on the roof, particularly when camping in forests or on cloudy days. Nothing wrong with trying to eek out an extra .25A/.50A, but as you have stated it may be more work than it's worth.

We have a Renogy solar suitcase and use the rear mounted solar charger until it went through one heck of a monsoon storm, ordered a slightly better water resistant solar charger from Renogy. We did go with a heavier gauge wire mounted directly to battery, simply deploy and connect.