If I connected a 24v battery to a 5v buck converter and I connected a 12v battery to a 5v buck converter. Then I connected the two 5v outputs together in parallel, Would this damage the batteries?
Thanks!
If I connected a 24v battery to a 5v buck converter and I connected a 12v battery to a 5v buck converter. Then I connected the two 5v outputs together in parallel, Would this damage the batteries?
Thanks!
Why are you wanting to do this ?
You could feed the power supplies to anodes of two diodes, cathodes connected together then to the buck converter.
That may be a long winded answer. I have two battery banks (a 12v and a 24v bank) that I want to try and keep charged with one solar panel system. To do this I am thinking it may be possible if I use a couple of ssr relays or a dpdt contactor to turn on one source (12v) and the other source off (24v) and the other on when the voltage of one gets below a threshold. However to keep the arduino powered constantly, I want to connect it to the 5v outputs that the solar controllers have. So, they would both be capable of keeping the arduino powered at all times to turn on/off relay and detect voltages. This may not be a good enough explanation for you to answer.
Thanks!
The two diodes will give you redundancy.
You should probably add a disconnect switch and fuse for both supplies too.
So, you are saying its possible? I am not sure I understand the diodes. I guess I didn't really give you the correct information to begin with. The 5v from each source are coming from the solar chargers. The solar chargers have 5v usb plugs built in. So, not a buck converter, I don't guess. I'm assuming the solar charge has one built in to it.
The diodes you are referring to would be connected to the 12v +line and the 24v + line? Or, to the two +5v outputs?
This is to prevent the 5v from traveling back in to the source that is not being used?
Thanks!
Referring to your post #1, draw a simple schematic of what you mean.
This is what I think you are saying with the diodes. A relay (controlled by the arduino) will keep one source on and one source off from the output of the batteries.
Thanks!
Is the above correct ?
What are the relays for ?
sorry. I think I’ve confused myself. Let me try to redraw what I’m doing. I’m not even sure what I’m really trying to do is coming from 2 different sources. I think I was all kind of backwards. Sorry.
Ok. I still don’t know that I’m going to make any sense, but it is definitely not like what I originally asked. I only have one solar panel system. I am going to charge the 12v battery. Have a 12 to 24v dc converter(maybe higher voltage for charging purposes) step up the voltage. Run it through another solar charger to charge my 24v battery. From both batteries, I want to be able to control the same outputs but only with one of them at a time. That’s where the relays come in. One relay will turn on/off the 12v output of the voltage drops below a certain voltage and the other will do the same for the 24v. The 12v battery will be permanently mounted and never be removed. However, the 24v may be removed some times from the system. This would obviously mean the 12v would need to run the outputs.
I don’t think The 5v coming out of each charger controller is even necessary in this setup?
Trying to wrap my head around it. Is this possible?
Let's start with this circuit and make changes to it.
Describe what you think you want using this image.
Both the 12v and 24v solar chargers have 5v usb ports built in. Like this:
100A Solar Charge Controller,Solar Panel Battery Intelligent Regulator 12V 24V,Multi-Function Adjustable LCD Display Street Light Controller,PWM Auto Paremeter Solar Panel Charger Controller (Blue) https://a.co/d/1Vn0AFy
The usb ports are what I am wanting to power the arduino with. Not planning to use a step down converter as in diagram because they are built in to the “battery chargers” of the diagram.
The battery chargers will obviously connect to the batteries. The batteries both 12v and 24v will then feed a panel that consist of the same exact outputs (I will need 5v, 12v and 24v outputs). Some times it will be the 12v battery feeding the outputs and other times it will be the 24v battery feeding the outputs.
Inside that panel the outputs will need be configured individually so that the 12v battery can step down to 5v and step up to 24v when the relay has the 12v battery as the source. If the 24v pack needs to be the source the relay will disconnect the 12v battery and connect the 24v battery. It will then need to be stepped down inside the panel to the same 5v, 12v, and 24v outputs.
The Arduino has to be powered all the time to be able to switch between the 12 and 24v battery banks. If I am thinking correctly, I will only need to power the Arduino from the solar charger that is charging the 12v battery. As it should always have power assuming the battery does not die.
Am I still making no sense? I am basically wanting to be able to use the solar panels to charge both the 12v battery and the 24v battery. Plus be able to run the same outputs (12v lights, 5v Wi-Fi router, 24v Poe device) from both.
Thanks!
No sense to use 2 batteries instead of 1.
Thanks, I know I only need one battery pack but here is my reason for using both. This runs a boat dock. The system is setup now where only a 12v battery is used for my outputs. The boat is parked under the dock 99 percent of the time and has a 24v battery pack for trolling. I want to be able to keep the 24v charged so when it is used for trolling, batteries will be charged. Plus, be able to use their storage AH to help run my outputs at night if needed.
Thanks!
In the description I gave, is it possible that could work? How could I make sure there was never a case where something went wrong and the 24v became parallel with the 12v overcharging the 12v battery? Would a fuse on the positive lines blow to prevent this?
Thanks!
I tried to draw a bit of a better diagram of what I am attempting to do. One thing I have considered is only using one I/O pin to switch between the two relays. Only one relay should ever be activated at a time. I am unsure what will happen if by some fault or accident both relays were ever activated. This would be like wiring the 12v battery and 24v battery in parallel. I know this isn't good.
By using one I/O pin to activate both relays (One relay activates on HIGH and other on LOW), shouldn't that eliminate the possibility of both becoming activated at the same time? Should I add in any other protection for this?
Solar Schem.pdf (41.1 KB)
Thanks!
This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.