theoldwizard1 wrote:
mchero wrote:
Cole Hersee link looks interesting. Continuous duty indeed but how many amps? I'm looking for 300 amp plus.
Why so much ?
If its purpose is to isolate the house batteries from the starting batteries during cranking and when the engine is OFF, it will only be ON when the engine is running and you are trying to charge the house batteries from the engine. I am certain that your engine alternator can not generate anything near 300A !
Personally, I would rather have a DC-DC charger. It will not allow reverse flow of current AND it will properly apply a multi-step charge on your house batteries.
Let's say my chassis batteries are low. Remember that Aux Start switch on panel next to driver. If you push that switch and crank her up you can EASILY surpass 200 amps.
I know, one day we where at Salisbury state beach MA. Spanking new 2019 Discovery backed into site across from us. Two guys plugged her in and shortly afterwards were walking around power pedastal with puzzled look on their faces. I walked over and asked what was up? "No lights inside, nothing!" Opened up battery bay and found 300 amp protecting house batteries blown! I asked them if they had a starting issue earlier? They responded yes! I asked them if they used the Aux. start switch to get the rig started, they responded yes.
So chassis batteries low, they pressed Aux start switch while they cranked it over. Started BUT blew 300 amp fuse.
That solenoid does indeed charge house batteries while driving down the road BUT will ALSO pass current from house batteries to main engine starter
Thus the reason I'm looking for 300 plus amps.
What the Discovery owner SHOULD have done, and others in like situations is hold down Aux. start switch for a couple of minutes BEFORE starting rig. Just like jump starting a car with flat battery. You need to wait a couple minutes before starting.
