I'm looking for some help I'm building a battery isolator using a DC solid state relay. I need to protect the SSR from fly back as there is a starter solenoid and starter motor so I was going to use a TVS diode but then I thought I need to allow for charging from the stator via a regulator rectifier so would a rectifier diode be a better option?
TIA steve
Please make and post schematics.
What is the actual device and it's specifications? A DC SSR is a mosfet with a transistor to invert the logic. People have been using a single diode as a battery isolator for generations without a problem. Why use a SSR?
The problem:
I have a motorcycle that I use for multi day trips, it has a parasitic drain on the ECU and drains the battery around 2 weeks this is not good for the battery as it is lead acid. I don't want to physically disconnect the battery as it is a pain to get to nor do I want to put it on a trickle charger.( I have a thing about charging batteries unattended)
The Solution:
To use a SSR-100-DD (3-32 vdc input, 5-220 vdc output) with a transistor timer (for the control) on the power line from the battery so it can disconnect the battery after 16 hours of inactivity. 16 hour because on a multi day trip I would not have to put any input day to day to reset the timer circuit then after the trip I can park the bike up, the timer runs out and disconnects the battery.
Options that I have considered are
A traditional relay but after 16 hours of inactivity and the relay energised would put the lead acid battery below 50% (where damage will occur).
A latching relay is way too expensive to buy with a 30 amp ratting plus makes the control circuit a bit more complicated and real estate is a premium.
So I opted for a SSR because the power consumption is really low 0.00425 amps @ 12v for the whole circuit which is great as it wouldn't discharge the battery to a damaging level, however I need the lead acid battery to be able to charge from the running engine and running the charging current backwards through the SSR would destroy it. I'm no electronics engineer, I'm just a guy with Google but I can't work out what type of diode would protect the SSR and allow charging, or is there a better option I haven't considered?
Seriously, if you have room for all this stuff, you have room to mount a proper switch to totally remove the battery from it's circuit.
it is 6 components that fits on a board 15mm by 20mm a battery isolator key takes up more space
Since this is an Arduino forum, where doe the Arduino fit?
ok I'm using a uno R3 to control the SSR I still have the same problem about protecting the SSR
Will do if I can get it to work
I'll wait.
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