What damages the Voltage Reg?

[f4phantomii]

There have been several recent postings, along with numerous others in the past, warning switching batteries AND/OR turning them off with a 1/2/All/Off switch will damage your voltage reg.

Clearly turning the switch to "Off" with the engine running is bad...even all the switches have warnings proclaiming the danger. This assumes you do NOT have a switch with built-in load shedding capability.

But is this also true of switching between batteries? The only harm I can see is the very momentary break in the circuit when you switch from one battery to the other. In fact, isn't this why the switches are set up to force you to switch go to "All" if you are switching from one to the other, thus truly minimizing any interruption in current flowing to at least one battery or the other.

Seems like if this were a problem, that the battery switch manufacturers would be warning against switching at all when the engine is running.

Has anyone verified if this is truly a concern or not? Or for that matter if the switches are engineered to keep that from being a problem?

-Michael

[Mumblerone]

This says it all! No problem switching when started to #1 or #2, just don't run on 'ALL'. Also, as you say, donot shut motors "OFF' with switch. I have no problem runnig both motors on battery #1 or #2, or for that matter starting both motors on #1 or #2.

Boston Whaler, "MUMBLER", 24' Outrage, twin 175 HP Evinrude Ocean Pros. Snowball, the cat...

[WildeOne]

You need a "make before break" type of switch to protect the charging circuit against a momnentary open circuit.

___________________________
a bad day fishing is always better than a day at work
___________________________
Jim

[f4phantomii]

Hmm.....not running the engines switched to "All" is an interesting twist....I've never seen that before.

It must be unique to your motor's electrical system for this to be the case, and thus the reason for the very obvious placarding to prevent damage. Very nice looking setup, by the way.

My OEM manual for my 1987 Evinrude 225HP specifically says it can charge up to three batteries connected in parallel. In fact, I routinely run with my switch set to "all" in order to charge both batteries while I'm running.

I'm guessing most other motors are set up this way as well...but I could be wrong. I guess the point being to check your manual first.

But as another poster suggested, in this thread an in others past, just spend the extra $10 and get the switch which prevents the problem in the first place....accidents will happen.

-Michael

[mbb]

I chose my switch after trying out several. I was amazed that some were so hard to get started to turn, that when it switched, you would accidentally go past the desired setting. It was possible to accidentally turn to OFF by overshooting the desired position.

Mine turns nice easy and smooth.

I did know a guy once that fried all the electronics on one of his motors by switching to both. It was cheaper to replace the powerhead with one from an identical motor with a boad LU than to buy all the new electrical parts and wiring harness.

[AGULHAS]

from my limited understanding of the electrics in a boat and their good friend and life line of electrolyte and lead i was under the understanding that the only harm of running in parallel is that (assuming you don't have some sort of one way valve thingie) if your one battery is lower then the others it may loose charge to the others- i guess equalize if you will. cause all you are really doing is charging two batteries.

[AGULHAS]

i meant to say if one battery has more charge than the others- not lower. sorry

[f4phantomii]

I agree that with both batteries ("all" position) powering electronics and without the engine running, that the weaker battery will tend to drain the stronger battery.

But in the case where the engine is running, you should have current flowing to both batteries from the engine. I would think that if the weaker battery was already drawing current, it shouldn't pull any from the other battery. It might however, draw more amps from the engine than the stronger battery, thereby slowing the charge rate of the other battery. But it definitely shouldn't draw down the stronger battery, unless you are seriously overtaxing your engines electrical system. There should be plenty of current to charge batteries with the engine running.

I think the reason the charging and running with the switch set in the "all" position is the fact that most people aren't diligent enough to switch to one battery or the other when they stop the engine. As I said before, with no engine running, the weaker battery will pull down the stronger one.

But I still haven't seen anyone say that switching between 1/All/2 (not to "OFF") is dangerous to your alternator, and if so, why.

-Michael

[Reel-Rascals]

quote:Originally posted by f4phantomii:
... I routinely run with my switch set to "All" in order to charge both batteries while I'm running ...

Mike:
Sounds good in theory, but it won't work that way. Say one battery is at 12.6 and the other is at 12.0 (for example purposes only!). Your charging system sees this as the average of the 2 readings when set to "All". So it senses 12.3.

It will try to charge both batteries based on that value. You run the risk of overcharging the higher volt battery, cooking off the electrolyte which could cause a plate to sulfate and cook/kill it.

Your other battery won't get a full charge. I also think I've heard that the rectifier/regulator unit could be damaged in a case of severe overcharging, but I'm not sure of that.

The school of thought is that you start on "All" only when needed and switch to a running position of "1" or "2".

Personally, I start & run the #1 battery on odd days of the week and do the same for the #2 on even days. Some go out on #1 and back in on #2 ... many choices there, but note the "All" position is not used. Hope this helps

"Life's too short to own an ugly boat ..."

[dry doc]

reel.... i have that situation all the time,
and simply charge the 12.0 only, as the other
is obviously full...dan