Re: Detroit 8.2 alternator
Posted: Fri Jan 07, 2022 12:11 am
Thank you for the kind words but I sure am not a legend, I believe in the pay it forward/helping others concept and try to help when I can, just like many other members here. Over the years people have been very kind and helpful to me, and pretty much all RVers know how much it sucks to be broke down, so we all just try to help each other the best we can (it is the way the world use to function in the old days).
Sorry, but I don't know much about the quality of various brands of isolators out there. Some have used Noco brand, Cole Hersey seems to be rated well, so you will likely be ok. I personally don't care for diode based isolators because of their inefficiency (0.7 volt drop), but more importantly, even though they do seem overall trouble free, when they do fail, and they will eventually, they often can wipe out the alternator. So for this reason I prefer to use a heavy duty solenoid for an isolator. One thing is for sure, the isolator you have now is way too small and wont live long with that strong of an alternator.
To answer you other question, the solenoid shown in the photo below your blue isolator is your boost solenoid. It looks very similar to mine, so it might be a White Rogers continuous duty solenoid, mine is rated for continuous duty. If you decide to make your boost solenoid do dual purpose, I would suggest to buy a spare solenoid, as the one you have is pretty old, but likely didn't see that much use. I could also help guide you through the changeover if you like, but that would have to be next week.
Regarding the isolator, I found this info on one of the boating supply sights that you should be aware of.
Note: Battery isolators also have a "per leg" rating which indicates the maximum current it can deliver to either battery. All Cole Hersee battery isolators have a per leg rating equal to half the alternator rating. Thus the 48162 with a rating of 200A has a per leg rating of 100A per leg.
If your house battery bank is four 6volt batteries, it could easily exceed the 100amp limit if the batteries are pretty discharged or you have a substantion load on the battery bank, while you are driving. So, going to a larger isolator, as a precaution, would not be a bad idea, or just switch to a solenoid based isolator.
The alternator you ordered seems to be correct on all the needed items, lets hope you receive the actual alternator with the described specs.
Sorry, but I don't know much about the quality of various brands of isolators out there. Some have used Noco brand, Cole Hersey seems to be rated well, so you will likely be ok. I personally don't care for diode based isolators because of their inefficiency (0.7 volt drop), but more importantly, even though they do seem overall trouble free, when they do fail, and they will eventually, they often can wipe out the alternator. So for this reason I prefer to use a heavy duty solenoid for an isolator. One thing is for sure, the isolator you have now is way too small and wont live long with that strong of an alternator.
To answer you other question, the solenoid shown in the photo below your blue isolator is your boost solenoid. It looks very similar to mine, so it might be a White Rogers continuous duty solenoid, mine is rated for continuous duty. If you decide to make your boost solenoid do dual purpose, I would suggest to buy a spare solenoid, as the one you have is pretty old, but likely didn't see that much use. I could also help guide you through the changeover if you like, but that would have to be next week.
Regarding the isolator, I found this info on one of the boating supply sights that you should be aware of.
Note: Battery isolators also have a "per leg" rating which indicates the maximum current it can deliver to either battery. All Cole Hersee battery isolators have a per leg rating equal to half the alternator rating. Thus the 48162 with a rating of 200A has a per leg rating of 100A per leg.
If your house battery bank is four 6volt batteries, it could easily exceed the 100amp limit if the batteries are pretty discharged or you have a substantion load on the battery bank, while you are driving. So, going to a larger isolator, as a precaution, would not be a bad idea, or just switch to a solenoid based isolator.
The alternator you ordered seems to be correct on all the needed items, lets hope you receive the actual alternator with the described specs.