Charging Dual Batteries with Single Alternator: Rectifier Diodes or Electronic Circuit Solution

Question

Hello Will such a solution work? The point is that after the charging process is completed, the current between the batteries does not wander. What is it for? 1 car battery, 2nd for use on the plot, sometimes a 12>230 inverter is connected to it. I would not like to lead to a situation where...

marqqv · Accepted Answer

Additional battery charging module - SLA Separator and everything works

marqqv · Accepted Answer

Additional battery charging system - separator - not only for cars, trailers and motorhomes

The device is designed to charge the additional battery while the car engine is running and prevent the main battery from discharging when the car is parked. The device monitors the voltage of the main battery - if it detects its increase above 13.5V, which only happens when the alternator is running, it will short its contacts, causing the current to flow to the additional battery. At the same time, the indicator informing the user about this will turn on. After immobilizing the engine, the system will open its contacts to prevent the main battery from discharging. A discharged battery would prevent the engine from starting later.

This way of working ensures:

- The primary battery is always charged with priority. When the engine is started, the primary battery will charge first, and only after it is fully charged will the secondary battery begin charging.

- If the alternator is unable to charge the batteries while the engine is running (e.g. temporary high current consumption), charging of the auxiliary battery will be interrupted.

- It will enable, using the control panel (which is an accessory), to support the power supply of devices with particularly high power consumption (e.g. winches) or engine start-up.

Battery isolator is used in:
- power supply system for caravans, motorhomes,
- powering all devices in the car from an additional battery: audio equipment, tourist refrigerators, winches in off-road vehicles, CB radio, etc.
- isolating batteries in other systems.

nuszek · Answer

Type in Google The battery in the motorhome and everything is lit.

cmepro · Answer

I will definitely review as advised, but I think the comments and opinions of a few colleagues will be just as useful, if not more so Thanks

cmepro · Answer

Oh looks very interesting ;)

And when using such a module, connecting the battery. car to the alternator remains the same?

And by expanding this system, it is possible to connect photovoltaic cells to it, mounted on the roof of the car, so that when you are on the plot for the weekend or longer, you can recharge the batteries. of the above-mentioned cells?

cmepro · Answer

A great working system

that was exactly what I was after

I have always believed in the knowledge of forum members here ;)

Just for the future, think about how to connect a set of photovoltaic panels to it to be able to charge the battery. camping, spending time somewhere by the water or in other natural circumstances, without having to start the car to recharge the battery. by the alternator.
> Any idea?

marqqv · Answer

Such a set can be connected separately to the second battery at a standstill and the separator will continue to protect in the event of not being recharged by the panels.

cmepro · Answer

What do you think about this connection? Any chance this will work?
The premise is quite simple.

The ON engine charges the battery. car and battery motorhomes and cuts off the charging from the solar panels thanks to the relay, so that there is no double charging of the battery during the day. motorhomes with an alternator and solar panels.

Engine OFF charging the battery. motorhomes with solar panels, accum. the car is disconnected from the motorhome system.

I wonder if the panels on a clear day will not give more than 12V, especially connected in this way, which can cause the relay to be damaged.

cmepro · Answer

I found such an electromagnetic relay and the question is whether it will work better. than the one in the previous picture?

manufacturer's links:
- http://www.fif.com.pl/produkt/916/918
- http://www.fif.com.pl/pub/File/download/INSTR...0elementy%20pomocnicze/PK-xP%20instrukcje.pdf

The point is that it's hard to predict what VDC will flow from the panels, because it depends on the weather. Theoretically 12VDC (under optimal conditions it can jump above 12VDC) but if I give 4 panels, I will connect them + to +, in which case the voltage will not rise to ~ 48VDC (or even higher).

Will the contacts [10, 11, 12] in this relay be able to pass such a current? I admit that I do not fully understand the whole description of the manufacturer, where did my question come from.

WRadek · Answer

I do not understand your layout a bit, but I will answer about the voltage on the panels. Unloaded panels, which takes place when the "solar" battery is charged, have a voltage even above 20V. But you probably shouldn't worry about it, because the battery is charged by the charge controller, and you have a relay between one battery and the other. Thus, the voltage on the relay will not be greater than on the charged battery.
The relay should be - in my mind - between the batteries, but it's probably better to use this separator for motorhomes? Proven by many...

cmepro · Answer

WRadek this SLC separator is for battery charging. camp. while driving, and the relay that wants to be mounted on the +xxVDC cable from the solar panels is to be used so that they are automatically disconnected when the voltage from the SLC is applied to the battery. camp. What is it for? I would not like to allow the situation that during the day while driving the battery. kemp are charged from 2 sources: 1st alternator by SLC 2nd from pan. elephant. by the charge controller.

WRadek · Answer

Would that be a bother? You're not overcharging.
Logic: from solar panels you charge through the controller. You don't overcharge. While driving, you charge the alternator first. You don't overcharge.
Why do you want to disconnect the panels from the controller? I don't understand.

cmepro · Answer

Well, I meant that I wouldn't charge while driving on a sunny day from 2 sources, panels and an alternator, so I wanted to disconnect it.
Not on the principle, because it will reload only on the principle because it can be loaded from 2 sources.

kafel123 · Answer

What exactly is such a beauty called and, for example, where can I buy something like this? You've got me very interested in this because it's exactly what I need. Thanks in advance for the info.

nuszek · Answer

Everything has to be served on a platter! And there are thousands of them, look for a model and ask if anyone has one and how it works.

kafel123 · Answer

I asked because I thought you had something specific in mind, and besides, I'm green in this topic, so I also considered you a competent person to give me such an answer. There is no laziness in this. How are you going to break a deal?

nuszek · Answer

This beauty is called a separator, a battery isolator or a charging module. Depending on the value of the voltage and the allowed current, there are different types. For example, when building his motorhome, Mr. Klimek spent about PLN 6,000 on electricity. /is on YouTube you can watch/.

kafel123 · Answer

Thank you for your answer. Now I know what I need to learn to choose well for my project 👍🏻 Greetings 👋🏻

Charging Dual Batteries with Single Alternator: Rectifier Diodes or Electronic Circuit Solution

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