Solar Controller for 2 Isolated Battery Banks (1 Viewer)

[JCruse]

OHMs law. The reserve capacity of your battery. How long you run the stereo, if you are running a sub woofer. If you like to listen to rap. Different variables. Also, what are you using to measure your voltage?

First things first.... I don't listen to RAP.

Now that we've got that settled.... I use a dash mounted volt meter that also does Ah, Wh, and a couple other things. I've also used a cheap DMM, a Fluke DMM, and all agree. Was running a sub but not now.

Anyhoo, I was just very surprised to hear that a cloudy day was so unproductive. What controller are you using?

 

[Dave 2000]

I use a Blue Seas VSR. If you choose 'dual sense' then a solar panel can be connected to either battery via a typical charge controller.

Very straightforward and ultra reliable, fitted mine circa 5 or 6 years ago and still perfect, you can find my setup in My LC 80 thread.

Regards

Dave

 

[Rwhat]

First things first.... I don't listen to RAP.

Now that we've got that settled.... I use a dash mounted volt meter that also does Ah, Wh, and a couple other things. I've also used a cheap DMM, a Fluke DMM, and all agree. Was running a sub but not now.

Anyhoo, I was just very surprised to hear that a cloudy day was so unproductive. What controller are you using?

I'm running renogy viewstar. Not sure how accurate the readout is, but mine will show .5-.75 amps cloudy. Looks like you got the right measuring equipment.
When I mention cloudy, I'm talking about no sun.

People should also double check thier charge controllers before they install. My first cheapie renogy controller didn't regulate and was out putting 22 volts.

 

[Dissent]

Looks like the Blue Sea ACR may be an option but I just read a post with a guy who's Blue Sea ACR failed and drained both batteries. Having both batteries connected at all makes me concerned as the potential for failure exists, even with the Morningstar Duo. The failure rate on a Blue Sea ACR is understandably rare but the potential still exists.

 

[Cruiserdrew]

Looks like the Blue Sea ACR may be an option but I just read a post with a guy who's Blue Sea ACR failed and drained both batteries. Having both batteries connected at all makes me concerned as the potential for failure exists, even with the Morningstar Duo. The failure rate on a Blue Sea ACR is understandably rare but the potential still exists.

No doubt anything can fail, but you also don't know how the install was done, how hot the environment was etc. Plus, the failure mechanism would be unlikely to "drain" both batteries. More likely a combined load drained both batteries. So take that story with a grain of salt. In my experience of 3 years and 3 ACRs they have been perfect. BlueSea's warranty is "as long as you own it". Hard to fault that. The combo of a solar panel powering your aux battery and when charged, automatically combining to top your main battery, is hard to beat.

You might check out the thread on the Victron MPPT controller-it's a nice device and will increase your power harvest 10-20%.

 

[Dave 2000]

Looks like the Blue Sea ACR may be an option but I just read a post with a guy who's Blue Sea ACR failed and drained both batteries. Having both batteries connected at all makes me concerned as the potential for failure exists, even with the Morningstar Duo. The failure rate on a Blue Sea ACR is understandably rare but the potential still exists.

Marine gear is designed for use in the middle of nowhere and may potentially save lives, so quality is top notch. Having two batteries drained would almost certainly need human intervention for example, the manual switch left in the 'ON' position, and then the lights left on for a couple of days, in other words self inflicted problems.

I mentioned my install because:

I Installed it myself, and I am no super tech.
It has an 'AUTO' function so fit and forget until needed.
You can plug a charging source (battery charger, solar panel, alternator) to any one of the two batteries and both get charged.
And finally it has been in there for years and ZERO problems, being used on and off road, so you have a real life recommendation as opposed to "my best mates brother in law's sister said blah blah".

I would not hesitate to use Blue Seas equipment, no affiliation yada yada.

Regards

Dave

 

[LandCruiserPhil]

The problem discussed above is exactly why I run parallel dual battery wire together and never separate. No controls to fail, solar charges both batteries given a simple set it and forget set up. The set up provides 80AH of usable power more than enough needed over nite power for 99% of the travels.

 

[Dissent]

Parallel config was actually the first option on the list and how I ended up looking at the Duo in the first place! LOL.

 

[Cruiserdrew]

The problem discussed above is exactly why I run parallel dual battery wire together and never separate. No controls to fail, solar charges both batteries given a simple set it and forget set up. The set up provides 80AH of usable power more than enough needed over nite power for 99% of the travels.

The problem is, with this approach, is that a dead cell in 1 battery takes down all of your electrical. And batteries are more likely to fail than a BlueSea ACR.

I assume you carry a Li jump pack for that specific circumstance.

 

[SWCruiser]

I run the duo. Has been working great for about a year. It's made specifically for rv applications. I have one panel and will be adding a second. My rig sits for months at a time and this helps me keep both batteries topped up when there are small draws. I've had a number of batteries go dead. It's a simple system that should have been offered long ago when it comes to simple controllers.

 

[Dissent]

I run the duo. Has been working great for about a year. It's made specifically for rv applications. I have one panel and will be adding a second. My rig sits for months at a time and this helps me keep both batteries topped up when there are small draws. I've had a number of batteries go dead. It's a simple system that should have been offered long ago when it comes to simple controllers.

Very nice, thanks for your feedback. Are you running the remote meter?

 

[LandCruiserPhil]

The problem is, with this approach, is that a dead cell in 1 battery takes down all of your electrical. And batteries are more likely to fail than a BlueSea ACR.

I assume you carry a Li jump pack for that specific circumstance.

Yes I do carry and recommend a jump box.

Not necessary true I recently lost one of my two batteries and seeing my voltage below the norm clued me to check the status.

 

[ZackR]

I don't have any first hand experience with solar setups on a truck but I have a lot with off grid setups to power FAA lights on communications towers. Some things I would recommend:

1. Use a charge controller with a low voltage disconnect, preferably one you can adjust. This allows the system to drop the load at a pre determined voltage as to protect the battery from full discharge.

2. Use a charge controller with MPPT. These controllers are better at harvesting more energy from a PV panel, especially in cold weather.

3. Size the charge controller correctly (large enough) so that it doesn't turn useful energy into wasteful heat.

4. Look into using two panels wired in series (24v) and see if that will provide more power than two panels in parallel (12v). This may be the case depending on the charge controller.

5. PV panels are very sensitive to shade and dirt. On some panels even a small amount of shade (on one corner of the panel) can drastically reduce the output.

 

[Dave 2000]

Toyota do run a dual battery 12v system in the HDJ100, principal thinking is less strain on an individual battery and hence longer life however, when any single cell fails the whole lot goes down.

In the event of a diode failing in the alternator both batteries get pulled down, a voltage regulator failure means both batteries get under charged or even cooked by excessive voltage, leave the lights on and.....yeh you get it.

Regards

Dave

 

[musthave]

First things first.... I don't listen to RAP.

Now that we've got that settled.... I use a dash mounted volt meter that also does Ah, Wh, and a couple other things. I've also used a cheap DMM, a Fluke DMM, and all agree. Was running a sub but not now.

Anyhoo, I was just very surprised to hear that a cloudy day was so unproductive. What controller are you using?

What dash mount voltmeter do you use?

 

[Dissent]

I've made a few decisions based on this excellent feedback you all provided. Here's the plan on the table:

1. I'm going to integrate a couple of Blue Sea Low Voltage Disconnects, one at the main truck battery on the fuse block lead ONLY. The other in the rear where my accessories are at the end of my 1AWG cable run. I'll exclude the Alpine amplifier and Puma compressor as they are key switched. I'll then be able to run truck circuits pretty much worry free of killing the main battery.

2. I'll buy a set of 80W panels and hinge/clasp them together for an off truck solution when my RTT is deployed. This gives me 260W combined if I'm hammock camping or 160W if I'm tent camping.

3. I'll then build up a portable battery pack, most likely run a LIFEPO4 40-50Ah battery, in a well ventilated plastic box and re-purpose the MorningStar PWM 30 (for use around the shed and backyard with a few additional panels) then bring in a Victron BlueSolar MPPT 75/15 or 100/30 with the Bluetooth dongle installed into the box. This box would then be secured in the truck and plugged into the 100W roof panel or I could remove it and use the folding 160w panel remotely. Either way I have much more flexibility at camp. All camping loads (mattress inflation, lights, phone charging, etc.) will hook to an Anderson 8x panel with standard blade fuses running on the LVD output of the solar controller. I'll monitor solar controller activity on my in-truck Android tablet.

3. Final step would be to integrate a Blue Sea ACR for the main truck battery/alternator and the LIFEPO4/Solar setup.

4. I still have my NOCO 100 jump pack for ultimate backup peace of mind.

That should fix all my issues and expand my flexibility. Thank you all for your input and understanding as I plow through yet another modification adventure!

 

[SWCruiser]

Very nice, thanks for your feedback. Are you running the remote meter?

Sorry. No I don't run the remote meter. It's best to run any electronics inside the cab if possible. Mine is in the chinook camper area and thus I didn't need the meter.