Solar > Charger > Start Battery. OK?

[kwon-offroad]

Fairly new to solar power for personal use. I don’t require massive power with complex wiring (i.e., dual batteries, etc.). The most we generally camp is 3-4days and between a Jackery 500 & EF Delta, we have plenty of power to keep us happy. We generally only run a fridge, shower(pump), lights, fan(summer), personal devices, etc. Sometimes an appliance or similar but not big draw.

Got into solar to keep things topped off now that our trips are getting longer and my job is ok with working from home (aka anywhere). So power consumption will rise but not tremendously.

Right now I have a Renogy 100w on the roof of the 100 into a Victron MPPT 75/15 straight to the start battery(flooded) with temp sensor bc of ambient difference (MPPT is incab DS kick panel). Then a 6awg lead direct from the start battery going to rear to a fuse block with an accessory panel with USB and 12v socket for fridge. 50a breaker at battery. All Blue Sea. The fridge has a low voltage cutoff and the accessory panel shows voltage for monitoring. Will add other direct leads to the fuse block but most likely not something with big draw.

My thought process is run everything off the accessory panel coming directly off the start battery when underway. At camp, run off the start battery fed by solar until it shows low voltage then flip over to Jackery/EF to allow the start battery to recharge and keep everything powered. Also have a 100w suitcase so I can charge the power banks off solar if it isn’t getting to the rooftop panel (lots of canopy in my area).

Anyone see issues with this system? Is sending solar charge direct to the start battery ok with the proper settings in the charger? What about charging and pulling load simultaneously from that same battery?

My last line of defense is a jump pack if I drain power completely.

 

[e9999]

I'm unclear as to what you meant exactly by "running off the direct panel", "remote power", etc.

 

[kwon-offroad]

I'm unclear as to what you meant exactly by "running off the direct panel", "remote power", etc.

Updated some language to clarify.

 

[e9999]

Sounds like you are saying that you have the solar battery controller and the alternator connected simultaneously to the starting battery and therefore possibly charging at the same time. That should be fine AFAIK if both alternator and controller are properly regulated/programmed (barring weird smart alternator shenanigans). Charging and having a load at the same time is also fine, that's what your truck is doing all the time, of course. It does not get any simpler than that sort of wiring, but of course there are practical limitations. The main one is that you only have one built-in battery, and your starting battery could be depleted and you won't be able to start your truck with it. So having some sort of automatic isolator to disconnect the battery from the load to avoid that may be one desirable addition. Of course, if you have a jump pack you may be able to still start the engine. But your starting battery -if not dual purpose- may be damaged if overly discharged too often. Now, your fridge having a low voltage disconnect may be OK battery wise (if not steakwise - get a high temperature alarm) as far as that is concerned, but lights etc could still bring the main battery down. Having said that, in principle I think with the portable batteries and portable solar panel, you can likely do it all manually and be OK if you have a total of 200W and a moderate load. I think of 100W as being about sufficient (but not very generous) to run a typical fridge in typical southern US climates. But you will have to keep on eye on the voltage of the truck battery, and especially so at night and early morning if you keep it connected to the loads. And having to get up in the middle of the night because your fridge has stopped is not great.
Then again, you do have some more batteries already: those in your powerbanks. Have you considered connecting those to the starting battery or solar system as effectively house batteries and keep those charged with the solar system(s) and/or alternator? You then basically increase your storage capacity and you don't have to connect and disconnect manually all the time. You may then want to look at isolators etc, though.

added: one thing came to mind. If you have the Victron connected to the starting battery, you may want to check its voltage settings and possibly match them to the alternator specs, because the alternator will likely bring the voltage up to around 14.4V very quickly and then the Victron may well shut down if set too low and then you get nothing from the solar system. OTOH, you don't want to set the Victron absorption voltage too high to avoid battery overcharge and possible issues with the alternator. Hopefully, the default settings are already there. But basically, I'm thinking that your solar system won't do much at all when the engine is running if the battery is not very low. Which is not surprising if the alternator is producing 1000W and the solar likely quite a bit less than 100. But short of something getting fried somewhere, that is not a problem besides wasting potential energy you could use to charge another battery. Anyways, fun stuff!

 

[kwon-offroad]

Thanks for the great feedback and you’ve understood my current set up precisely. Yes, the limitations are there. I’m willing to live with them for the time being, but the fridge high temp alarm is a great idea. I even think I have one stashed away somewhere when I was in catering. Charger is set to the dual duty battery specs and seems to react appropriately during bulk, abs, float. For now the solar is there exclusively to support camping recharge so I’m not worried about wasting captured energy. That will most likely change next season though and I may rewire so it feeds the EF Delta with an isolator in place.

 

[toadshade]

What about charging and pulling load simultaneously from that same battery?

This kinda goes with a question I was just trying to research. Could you run your 12V stuff from the output on your solar controller? That way it is basically a DC/DC converter and will give the correct voltage at all times? In my case I have an Epever MPPT solar charger that has an output for load. I am having some issues with some components and I was thinking of routing some of my items like my fridge to the output from the solar controller.

 

[z531519]

i have somewhat a similar setup, a victron and a mounted 100w panel to charge the main/starter battery. I have a line off Victron's Load Output to provide accessory power and charging the Ecoflow 600. I have the fridge, etc connected to the EF.

You can use the custom load output settings to sense when it can turn on/off. If i remember correctly, mine turns off at less than 12.4V which gives me a good margin for keeping the main batt charged overnight. It will start back on when it senses > 13v which is when you start moving.

I have a foldable 100w supplement panel for those times i am staying put (or out on a day hike) and need the extra charging power for the EF. In that case, i hook up the hard mounted and this extra 100w panel directly to the EF.

 

[kwon-offroad]

This kinda goes with a question I was just trying to research. Could you run your 12V stuff from the output on your solar controller? That way it is basically a DC/DC converter and will give the correct voltage at all times? In my case I have an Epever MPPT solar charger that has an output for load. I am having some issues with some components and I was thinking of routing some of my items like my fridge to the output from the solar controller.

That’s an option, yes. Not sure what issues you were having and on what vehicle but if you were using the standard 12v socket there may be too much voltage drop to support the fridge when the compressor kicks on. Another advantage to use the load output is to capture the data from the controller. I went direct from battery to get the most robust voltage feed to the back, to overbuild it. I don’t care to see what my loads are doing as far as they’re being fed with a good current. There are pros/cons to both wiring paths.

i have somewhat a similar setup, a victron and a mounted 100w panel to charge the main/starter battery. I have a line off Victron's Load Output to provide accessory power and charging the Ecoflow 600. I have the fridge, etc connected to the EF.

You can use the custom load output settings to sense when it can turn on/off. If i remember correctly, mine turns off at less than 12.4V which gives me a good margin for keeping the main batt charged overnight. It will start back on when it senses > 13v which is when you start moving.

I have a foldable 100w supplement panel for those times i am staying put (or out on a day hike) and need the extra charging power for the EF. In that case, i hook up the hard mounted and this extra 100w panel directly to the EF.

How’s the EF charging off the load output? My understanding was that function wasn’t designed for charging as it normalizing voltage from what it sees there and the battery posts. And what I could find on Victron’s support BBS was most saying it shouldn’t be used to charge a power bank. Interested to know your real life results.

I do at times put the power bank between the fridge and battery so to charge it while keeping the fridge running. But that’s not my go to setup.

 

[z531519]

How’s the EF charging off the load output? My understanding was that function wasn’t designed for charging as it normalizing voltage from what it sees there and the battery posts. And what I could find on Victron’s support BBS was most saying it shouldn’t be used to charge a power bank. Interested to know your real life results.

i don't see how that can be a problem since the EF will just be like any other load. I can't remember exactly what i have but the load output is rated to 15A output which is within the load of the EF when pulling in car adaptor mode. But yeah if you can point me to a link where it talks about what i am doing wrong, i'd love to learn.

Real life result is it seems to work. My power bank keeps the fridge running overnight while the load output charges it. Once the engine is off, it will keep charging the EF until i hit my low voltage cutoff. In my last trip (2 weeks) to UT/AZ, my fridge run non-stop so the EF just pulled power non-stop and so far i did not fry anything (other than ourselves from the heat wave).

Why do you prefer plugging your fridge straight off the batt? In my case, the reason why i use the power bank is to keep the main batt topped off, and healthy. The power bank has an advantage that i can deplete it plus it will carry the appropriate voltage required by the fridge to keep running.

 

[kwon-offroad]

i don't see how that can be a problem since the EF will just be like any other load. I can't remember exactly what i have but the load output is rated to 15A output which is within the load of the EF when pulling in car adaptor mode. But yeah if you can point me to a link where it talks about what i am doing wrong, i'd love to learn.

Real life result is it seems to work. My power bank keeps the fridge running overnight while the load output charges it. Once the engine is off, it will keep charging the EF until i hit my low voltage cutoff. In my last trip (2 weeks) to UT/AZ, my fridge run non-stop so the EF just pulled power non-stop and so far i did not fry anything (other than ourselves from the heat wave).

Why do you prefer plugging your fridge straight off the batt? In my case, the reason why i use the power bank is to keep the main batt topped off, and healthy. The power bank has an advantage that i can deplete it plus it will carry the appropriate voltage required by the fridge to keep running.

I may have misunderstood the posts I found mistaking the term “battery”. The caution is not to use it to charge another aux battery but seems a power bank is ok, because the output can’t determine when to bulk, abs, or float effectively. So in my case looks like I can connect it and run to the rear as well. That’s great news.

The reason it’s connected straight off the battery is solely due to how my system evolved and was built out over time. The solar charger was added to an existing circuit.

 

[e9999]

I'm assuming that the Victron's load output voltage will match that of the main charged battery, so that voltage will reflect the load cycle phases. If the 12V charging input of your portable device accepts the normal range of voltages it should be fine. As for connecting directly another battery, there may perhaps be funny things going on if they were at very different charge levels but might still work in general after the batteries are "synchronized". You may want to ask Victron directly, they have been very responsive to questions in the past.
The Victrons are highly programmable and modular, you can do a lot of things, there are even communication ports that can control various devices with PWM signals and the like. And being able (IIRC) to program the cut-off and cut-in voltages for the load output is very helpful. I think there may even be some sort of delay built in for those to avoid being erroneously tripped by high inrush currents leading to temporary low voltages. There is also a "streetlight" function to control external lights based on time of night. It's pretty well done overall. And of course they have various battery disconnect etc devices that you can mix and match.
If you're going to connect the fridge directly to the load output, you may want to check first the inrush current because I think the load output is protected at 15A. I don't know what would happen but it may trip or blow a fuse maybe. Your typical fridge uses 5A or a bit under normally, but a compressor motor will draw a lot when starting. I would not be surprised it that were to exceed 15A. I've blown an inverter before because of that.
I think that if you can use your power banks as house batteries while still keeping them "portable for other uses" you will greatly improve your system's usability and versatility. I am inordinately fond of Anderson PowerPoles connectors for 12V wiring admittedly, so I can't help but recommend those to make the system as modular as possible. You can then add, remove, replace devices, and reroute the wiring very easily. I'd even look at using a PP instead of the OEM fridge input connection if yours is not fully reliable (some are known to disconnect at inopportune times). Another advantage of having the fridge close to a powerbank is that this will reduce the chance of the fridge turning itself off because of otherwise voltage drops in the line from the main battery.

added: another potential issue came to mind: if you use the load output be sure to check the settings carefully. In particular, IIRC there is a "Battery life" (or something like that) algorithm that may change the voltage cutoffs after some time based on the history of battery charging/voltage. So it may work for some time just fine, you're happy and then after a while the Victron will decide it needs to protect your battery and will suddenly cut off the load. Which is not great if it's a fridge with all your desert trip food...

 

[LandLocked93]

Right now I have a Renogy 100w on the roof of the 100 into a Victron MPPT 75/15 straight to the start battery(flooded) with temp sensor bc of ambient difference (MPPT is incab DS kick panel).

Anyone see issues with this system? Is sending solar charge direct to the start battery ok with the proper settings in the charger? What about charging and pulling load simultaneously from that same battery?

So... @ the Victron, the solar panel connects to the PV pair connectors and your start batt is connected to...the 'Battery' or 'Load' pair connectors?
In either case, the Victron sees both the start battery load and the loads on the other end of 6ga run to the back as a single load. (but really curious which ones you're using for start batt)
It's output on the 'Load' pair connectors is split between the two actual load paths by 'least resistance' - start batt most definitely winning.
Unless it is fully charged, then the Victron output will lean toward the loads on the 6ga line, if any. If none there, it should turn off seeing a shutoff trigger has been reached. (soak/normalize/etc)

Keeping mind 100W@12v is only 1.2Adc nominal and disregarding the voltage drop, it's barely enough to run the average fridge much less start it.
How do you control manual, functional power cutoff to the controller? Guessing it's always on otherwise?
The setup sounds solid as you've had no issue relative to your initial concerm?

 

[gxblade1]

OP, I'm in the area. Sent PM.