PieterH's remote battery Charger

[Fanie]

Thsi is about as easy as it gets.

You need a Normally Open Push button switch, a relay, 1k resistor, and an LED.

The relay should have more than one set of cantacts as the one set will be used to latch the relay when the ignition is on and the PB is pressed.  The momentary power to the relay coil will switch the relay on and the relay will remain powered through the extra contact until the ignition is switched off to disconnect the two batteries.

The LED is ON when the charging has not been activated by pushig the button.  So when you started the vehicle and the LED is ON, the remote battery is not charging.  When you press the button, the LED goes off and the remote battery charge.  The LED is thus your reminder that you did not activate the charging yet.

I would recommend you use an industrial relay, you get some with a 10A contact rating and 4 sets of contacts, one set is then the extra contact while the other sets serve as the main contacts.

 

 

[Fanie]

You can also use more than one relay.  The 12V relay coils are connected together so if one relay gets power, they all get power.  The one relay contacts serve as the latch, the other relay's switch the power to the remote battery.

On the main contacts wiring.  If the remote battery is flat it is going to demand a lot of current for a while.  The wiring should be a fine multi-stranded wire and at least 4mm dia  or thicker.  Keep in mind that the wire will also serve as the drop resistor between the two batteries to limit the current.  If you can get, get wire with a silicone insulation and sleeve it where it passes through any body work.  The longer the wire, the more voltage drop you will get and the less current is initially charged to the remote battery.  Thumb suck, I would say 4m to 5m at least.

The circuit just shows how more than one relay is connected, it's exactly the same as above otherwise.

 

[Fanie]

The relay(s)that switch the power to the remote battery should have at least 30A contacts.

 

[pieterh]

Dankie Fanie.
Dit maak die saak somer baie maklik

 

[Fanie]

Jy's welkom Piet.

Persoonlik dink ek daar is heelwat merite in 'n solar paneel, jy hoef dan nie kort-kort die voertuig te laat loop om die battery weer lewe te gee nie. Die stroombaantjie bo is goed vir as jy ry.

Die nadeel van 'n solar paneel is diefstal, en as jy hom op jou voertuig sit dan moet die' in die son staan. 'n Moontlike oplossing is dalk om die solar paneel op 'n sleepwaentjie te sit waar daar dan ook 'n alarm ingebou kan word wat sal waarsku as iemand daar peuter.