hackableFM
New Member
I've done a bit of searching and can't come up with what I need.
I have a microwave, Kettle & Toaster in the back of my van.... (You Can Laugh now!) all three running from a 2KW Inverter. I have a second battery running the inverter. (Actually there's two 'second' batteries in parallel).
I have built a voltage sensing circuit which monitors the Main Van Battery and activates a relay (A 'Glow plug' relay ripped out of an old Land Rover from a scrap yard) in order to 'Split Charge' my second battery.
The circuit actually monitored the Main Van battery and switched on the relay when it saw the voltage rise to a level above approx 13.2V which only happens obviously when the alternator is charging the main battery.... I was as Proud as punch when it activated but then it failed. My problem was when the battery voltage dropped below 13.2V and the relay de-energised, The back EMF seemed to be sensed by the circuit although I had a diode across the relay to kill it, This seems to cause the circuit to reset and activate the relay again. This led to a vicious circle of the relay switching on & off every half second.
After various attempts at solving this problem over the space of a week I got annoyed and needed the Microwave to heat my lunch so I ripped out the circuit and reverted to twisting the Relay 'activate' wire to a 12Volt feed in order to manually charge the secondary battery.
My next problem arose when I left the Relay switched on for a couple of hours by accident and the relay gave up and died in a cloud of smoke. Clearly the relay wasn't designed to be left switched on for any length of time since it was a 12V relay and being run on a 12V battery.
Anyway, I'll cut to the chase.... I have bought some of these EV200HAANA Relays from E-bay.
Can anyone recommend a decent 'Split Charger' circuit other than the basic link to the Alternator's 'Charging indicator' light on the dashboard, to drive my new relays? I am not scared of using a PIC Microcontroller project, In fact I would just love a link to something which has been built and tested which gives an LCD readout of battery voltages etc etc. I am just starting to learn the basics of Microcontrollers and this is the sort of thing which would put a PIC to good use isn't it lol. Anyway, I've pulled enough hair out and I need a working circuit that I can just build & fit so I can have a nice hot coffee while out at work!
Thanks for reading this, If you didn't get bored half way through and skip to the next thread lol.
Hopefully...
hackableFM.
I have a microwave, Kettle & Toaster in the back of my van.... (You Can Laugh now!) all three running from a 2KW Inverter. I have a second battery running the inverter. (Actually there's two 'second' batteries in parallel).
I have built a voltage sensing circuit which monitors the Main Van Battery and activates a relay (A 'Glow plug' relay ripped out of an old Land Rover from a scrap yard) in order to 'Split Charge' my second battery.
The circuit actually monitored the Main Van battery and switched on the relay when it saw the voltage rise to a level above approx 13.2V which only happens obviously when the alternator is charging the main battery.... I was as Proud as punch when it activated but then it failed. My problem was when the battery voltage dropped below 13.2V and the relay de-energised, The back EMF seemed to be sensed by the circuit although I had a diode across the relay to kill it, This seems to cause the circuit to reset and activate the relay again. This led to a vicious circle of the relay switching on & off every half second.
After various attempts at solving this problem over the space of a week I got annoyed and needed the Microwave to heat my lunch so I ripped out the circuit and reverted to twisting the Relay 'activate' wire to a 12Volt feed in order to manually charge the secondary battery.
My next problem arose when I left the Relay switched on for a couple of hours by accident and the relay gave up and died in a cloud of smoke. Clearly the relay wasn't designed to be left switched on for any length of time since it was a 12V relay and being run on a 12V battery.
Anyway, I'll cut to the chase.... I have bought some of these EV200HAANA Relays from E-bay.
Can anyone recommend a decent 'Split Charger' circuit other than the basic link to the Alternator's 'Charging indicator' light on the dashboard, to drive my new relays? I am not scared of using a PIC Microcontroller project, In fact I would just love a link to something which has been built and tested which gives an LCD readout of battery voltages etc etc. I am just starting to learn the basics of Microcontrollers and this is the sort of thing which would put a PIC to good use isn't it lol. Anyway, I've pulled enough hair out and I need a working circuit that I can just build & fit so I can have a nice hot coffee while out at work!
Thanks for reading this, If you didn't get bored half way through and skip to the next thread lol.
Hopefully...
hackableFM.