anyone have any info on charging an aux battery off my charging system on my 2015 Indian chieftain. want to use it for camping and such
Thank You so much forthe input Im giving it a try this weekendHi Jack,
Welcome to the forum!
If your batteries are well matched in age and capacity rating, you can expect them to be reasonably happy being charged in parallel. In that case, you can get by with a simple "Battery Isolator" which is designed to place the aux. battery in parallel with the starting battery when the charging system is working, and isolate it (for camping use) when no power is being generated. Isolating your aux. battery automatically means your system can't compromise your starting battery by mistake. This can be as simple as a relay.
If you want to use batteries that are NOT reasonably well matched in capacity, charging them in simple parallel will likely lead to overcharging the weaker battery.
I've heard of folks using solutions as simple as a selection switch (make before break is important here, in my opinion) that lets you switch either/or between the starting battery and the aux. battery, but this only works as well as your ability to monitor the state of your batteries and remember to switch between them.
If you are handy, there are are DIY circuits and various gadgets available online.
It I wanted to do something like this, I'd be tempted to buy less than $10 in parts and make myself a gadget that when I pushed a button, the starting battery got dropped from the charging circuit, and the aux battery got cut in, for a predefined period, like two hours, after which it they were swapped back. They would also default back to starting battery if the circuit was powered down. At any point I would be able to verify the voltage of the aux. battery, with a 2nd pushbutton, whether it was charging, or isolated. Reading the aux battery's voltage is how I would know to keep pushing the "charge aux" button. I prefer gadgets that keep me in the decision loop.
I think I'd need:
A 2P 2T relay or a pair of 1P 2T BL_ GX- Car Automotive DC 12V 30A 4/5 Pin Relay Automotive Relays Sweet | eBay
A Chinaman's 12V timer DC 12V NE555 Adjustable Delay Relay Shield Timer Time Relay Switch Module 0~10s | eBay
A mini voltmeter Mini Red LED Panel Voltage Meter 3-Digital Adjustment Voltmeter RED | eBay
A couple of pushbuttons pushbutton | eBay
If I'm reading this correctly then the bike would never be running off a battery alone and one of the batteries would always be working with the charging system while riding the bike.I pushed a button, the starting battery got dropped from the charging circuit, and the aux battery got cut in, for a predefined period, like two hours, after which it they were swapped back.