10-24-2022, 11:48 AM
@arcticdude - that is awesome! I hope you post photos as you go through the stages.
There is some confusion about the alternator. I'm not suggesting that they run at 24v. That was my entire point -- that they are running at 12v, HOWEVER, they are intended to run at 24v. Therefore, at the same gauge wire, running at 12v as Newell does, you're effectively increasing resistance and reducing the effective current, which is a substantial help on the alternator's load.
Keep in mind that the 50DN which Joe has -- it's rated for 75% output at *idle*, according to their specs. That's a very high-end alternator.
I'm seeing comments made about traditional alternators as if they are similar to one that outputs 75% at idle and runs a 9" stator -- those are worlds apart, lol.
--
Joe,
Just to put things in context... You quoted a StackExchange comment re:Open Circuit batteries. Of course an "open circuit" battery would kill just about anything/everything. That's the anomaly that one would become alerted to before doing damage -- much like a reliable engine that will also go bad without oil.
If we're going to look for exceptions-to-the-rule, I could brainstorm dozens of different situations that could kill your alternator.
Of course none of this is (not in any way) related to intelligent VSR's and DC-DC chargers --vs-- isolators. In fact, it's more reason that VSR's and DC-DC chargers are a superior alternative to isolators.
Keep in mind -- in an "open circuit" battery, an isolator will still connect because the voltage will be high enough for an SLA-threshold isolator and therefore, the exception-to-the-rule that you mention is worse in a situation with a simple / non-intelligent isolator versus a more intelligent option, such as programmable voltage cutoff.
Based on your reply, there is substantial confusion on the Blue Sea product. It may be that I linked the wrong product or that there is a miscommunication somewhere.
Yes, they are very popular in Yachts. Yes, Yachts use better quality equipment than RV's in almost every situation that I'm aware (relative to their quality level, of course). No, there is not some reason why using a solution that is popular with yachts is somehow less ideal on an RV. In your case specifically, you have an issue with corrosion; gear that is designed to tolerate a marine environment is ideal in that instance.
For starters, the VSR that I included is a magnetic *latching* unit, meaning that it shouldn't require more than the 40ma current draw, which is substantially less than self-discharge on a 6x8D battery bank (for relative perspective).
Second, every one we've used has a 30-second and 120-second requirement before switching over, they also have BOTH high/low voltage cutoffs, which add additional protection over an isolator. You'd have to review the user manual; however, there is no scenario where they flap/oscillate.
Third, there is no situation where paralleling more batteries should cause the inverter-charger to burn out. Your inverter-charger is set for 24x7 duty-cycle. If it's not, dump it and find another -- I've never had an issue under any amount of load for any amount of time, when properly cooled. Adding more parallel batteries does not require more current in your unique situation; a 6x 8D battery bank is already utilizing the full load, you merely have a longer cycle if for some reason both sets of banks were low SoC (again, that's a very strange situation and in the majority of real-world cases, this is a major feature, not a drawback).
These esoteric scenarios appear to be strange to me. It's a bit like saying that someone doesn't want to use the the best/highest-speed tires, because it will allow you to go faster and if you took advantage of that, it might over-rev the engine or some such secondary/tertiary side-effect of the added feature/capability. The idea that a positive/added-feature allows you to do something impractical that can be viewed as a negative, to me that's a bit counter-intuitive.
Regarding the Blue See offering to connect from either side -- it's just one option, of dozens. If you prefer a one-way model, by all means, there are plenty of others. I was merely recommending one that we had used effectively, one where we have first-hand experience, back before new battery chemistries became affordable.
By all means, for your application -- definitely go with the isolator.
For others that stumble on this post, I think it's doing them a disservice to suggest that VSR's are a sub-par or questionable alternative to isolators. Or far worse -- that somehow isolators will save your alternator but a VSR or DC-DC will not, when the opposite is true.
That's just my opinion/experience. I certainly could be wrong. Good luck to you.
There is some confusion about the alternator. I'm not suggesting that they run at 24v. That was my entire point -- that they are running at 12v, HOWEVER, they are intended to run at 24v. Therefore, at the same gauge wire, running at 12v as Newell does, you're effectively increasing resistance and reducing the effective current, which is a substantial help on the alternator's load.
Keep in mind that the 50DN which Joe has -- it's rated for 75% output at *idle*, according to their specs. That's a very high-end alternator.
I'm seeing comments made about traditional alternators as if they are similar to one that outputs 75% at idle and runs a 9" stator -- those are worlds apart, lol.
--
Joe,
Just to put things in context... You quoted a StackExchange comment re:Open Circuit batteries. Of course an "open circuit" battery would kill just about anything/everything. That's the anomaly that one would become alerted to before doing damage -- much like a reliable engine that will also go bad without oil.
If we're going to look for exceptions-to-the-rule, I could brainstorm dozens of different situations that could kill your alternator.
Of course none of this is (not in any way) related to intelligent VSR's and DC-DC chargers --vs-- isolators. In fact, it's more reason that VSR's and DC-DC chargers are a superior alternative to isolators.
Keep in mind -- in an "open circuit" battery, an isolator will still connect because the voltage will be high enough for an SLA-threshold isolator and therefore, the exception-to-the-rule that you mention is worse in a situation with a simple / non-intelligent isolator versus a more intelligent option, such as programmable voltage cutoff.
Based on your reply, there is substantial confusion on the Blue Sea product. It may be that I linked the wrong product or that there is a miscommunication somewhere.
Yes, they are very popular in Yachts. Yes, Yachts use better quality equipment than RV's in almost every situation that I'm aware (relative to their quality level, of course). No, there is not some reason why using a solution that is popular with yachts is somehow less ideal on an RV. In your case specifically, you have an issue with corrosion; gear that is designed to tolerate a marine environment is ideal in that instance.
For starters, the VSR that I included is a magnetic *latching* unit, meaning that it shouldn't require more than the 40ma current draw, which is substantially less than self-discharge on a 6x8D battery bank (for relative perspective).
Second, every one we've used has a 30-second and 120-second requirement before switching over, they also have BOTH high/low voltage cutoffs, which add additional protection over an isolator. You'd have to review the user manual; however, there is no scenario where they flap/oscillate.
Third, there is no situation where paralleling more batteries should cause the inverter-charger to burn out. Your inverter-charger is set for 24x7 duty-cycle. If it's not, dump it and find another -- I've never had an issue under any amount of load for any amount of time, when properly cooled. Adding more parallel batteries does not require more current in your unique situation; a 6x 8D battery bank is already utilizing the full load, you merely have a longer cycle if for some reason both sets of banks were low SoC (again, that's a very strange situation and in the majority of real-world cases, this is a major feature, not a drawback).
These esoteric scenarios appear to be strange to me. It's a bit like saying that someone doesn't want to use the the best/highest-speed tires, because it will allow you to go faster and if you took advantage of that, it might over-rev the engine or some such secondary/tertiary side-effect of the added feature/capability. The idea that a positive/added-feature allows you to do something impractical that can be viewed as a negative, to me that's a bit counter-intuitive.
Regarding the Blue See offering to connect from either side -- it's just one option, of dozens. If you prefer a one-way model, by all means, there are plenty of others. I was merely recommending one that we had used effectively, one where we have first-hand experience, back before new battery chemistries became affordable.
By all means, for your application -- definitely go with the isolator.
For others that stumble on this post, I think it's doing them a disservice to suggest that VSR's are a sub-par or questionable alternative to isolators. Or far worse -- that somehow isolators will save your alternator but a VSR or DC-DC will not, when the opposite is true.
That's just my opinion/experience. I certainly could be wrong. Good luck to you.