Period battery switch blues

[partingclouds]

Lately the battery selector won't always activate the #1 position battery. I've cleaned all terminals and cables thinking that might help restore the function, but it didn't solve the problem. The switch is a sealed unit, and feels alright when the selector is turned, but I am wondering if it's corroded inside. Any ideas would be greatly appreciated.

[S/V Illusion]

a simple voltmeter set to conductivity will show whether it is defective or some other problem has manifested itself.

[partingclouds]

Lately the battery selector won't always activate the #1 position battery. I've cleaned all terminals and cables thinking that might help restore the function, but it didn't solve the problem. The switch is a sealed unit, and feels alright when the selector is turned, but I am wondering if it's corroded inside. Any ideas would be greatly appreciated.

[tkeithlu]

You have two choices. Toss it, or open it. Before you toss it, open it, and see if you can repair it inside. Or, just toss it, but you have nothing to lose, and at the minimum you will learn how they work inside and will be able to post your understanding the next time someone on the forum has your problem. I'd like to know what you find. Maybe some pictures?

[Jammer]

Battery switches are wear items that require periodic replacement.


Knife switches are available that will last "forever" but they are big and expensive.

[Jammer]

I replied in your other thread.

[antoha]

are you sure it's the switch? at some point I was having an intermittent connection for my house battery, turned out the cable (from battery to negative bus, in my case) corroded out. this was happening as the cable was flexing, so the problem was less visible in nicer sailing conditions.

can you isolate the problem?

[MarkSF]

One of the Blue Sea Systems switches should slot right in.

[stormalong]

Battery switches are not expensive. Just replace it.

IIRC you original is a Guest. I am not a fan of Guest. As someone else said - get a Blue Sea Systems switch and be done with it. Life is too short to be wasting time on taking apart and trying to fix an old switch.

[Chuck Hawley]

Battery switches are generally designed to conduct high currents, but they are not so good at switching high currents. In other words, let's say you had a giant incandescent light that would illuminate as soon as you turned the switch to ON. Let's say this light draws 200A @ 12V. If your battery switch was the only way to turn it on and off, the contacts inside the switch would be subject to arcing and would eventually fail.

On the other hand, if the only function for the switch is to select one or more batteries to be available, and something ELSE does the switching, the battery switch only has to deal with the heat caused by some resistance on the contacts. Then it's more of a surface area/friction/cleanliness issue.

It's my understanding that when Blue Sea Systems got into the battery switch market, they helped UL to rewrite the standards so that it was clearer as to whether the standards applied for switching or conducting, and I think they also clarified the time over which the switches were supposed to conduct their rated current. Under what circumstances would a battery switch be expected to conduct 350A for 30 minutes? A giant inverter? A DC propulsion motor? What's the application?

This may be documented somewhere on the Blue Sea Systems pages. Great company that takes whatever there is in the industry and generally makes it much better.

Chuck

[Chuck Hawley]

Battery switches are generally designed to conduct high currents, but they are not so good at switching high currents. In other words, let's say you had a giant incandescent light that would illuminate as soon as you turned the switch to ON. Let's say this light draws 200A @ 12V. If your battery switch was the only way to turn it on and off, the contacts inside the switch would be subject to arcing and would eventually fail.

On the other hand, if the only function for the switch is to select one or more batteries to be available, and something ELSE does the switching, the battery switch only has to deal with the heat caused by some resistance on the contacts. Then it's more of a surface area/friction/cleanliness issue.

It's my understanding that when Blue Sea Systems got into the battery switch market, they helped UL to rewrite the standards so that it was clearer as to whether the standards applied for switching or conducting, and I think they also clarified the time over which the switches were supposed to conduct their rated current. Under what circumstances would a battery switch be expected to conduct 350A for 30 minutes? A giant inverter? A DC propulsion motor? What's the application?

This may be documented somewhere on the Blue Sea Systems pages. Great company that takes whatever there is in the industry and generally makes it much better.

Chuck