RMG failsafe - why turn it off?

[Rob Guyatt]

Rick, no not drinking or sniffing illicit substances. Just a little hay fever which I'm prone to this time of the year. Poor old me [:)]

Al had you been drinking[;)] You need to change to a different drop. Have a glass or two of "medicinal" Port before bed. Always get a good night sleep that way.[|)]

Don't be concerned about paying for SmartWinch features you're not interested in. It's ALL software based. No extra hardware is used. And software is not factored into product costing. If it was even I couldn't afford a SmartWinch[:D]

The bottom line is that low battery shutdown will only ever occur if either your wiring or batteries are not up to what it should be OR the battery is too low. Rather than turning the feature off for doing its job, fix the fault in your electrical system.

Admittedly in early models it was not as good as it is now. It was a permanent shutdown and a short term voltage drop due to other device pulling current could set it off. But that an other device could set it off is still showing that the system is not up to the current demands of the battery and or wiring.

It is more robust now due to immediate recovery of the winch if it was just a short term voltage drop. And also the voltage sampling is taken over a longer period so that short current spikes are less likely to set it off. But all I am doing by setting it up that way is making it less likely that it will show up the inadequacies of the electrical system.

As I am writing, I just had an idea of a new method of battery testing (in addition to the existing system). I have already mentioned to you that the voltage sampling is not done while the winch motor is running. But if it was, this would be a very good way to test the electrical system. I shouldn't think aloud like this but I am thinking that if low battery monitoring is turned on by the user, it could then, each time the winch is turned on, do a quick self test run out and back and read the battery immediately after the motor is started to capture the maximum voltage drop. How I could get the winch to then report the result is another question. Will think about that.

Now before anyone says "no more complexity please" I did say "if the user turns the system on" remember that low battery monitoring is turned off be default when new winches are shipped. So no need to even think about it if you couldn't be bothered. But for skippers wanting a way to keep track of black wire corrosion or battery health etc. it could be an assistance.

I agree with Al. Let skippers be responsible. But it is not <i>irresponsible</i> to use aids such as multimeters or RMG FLASH Voltage Display to keep track of battery voltage and nor is it to use low battery monitoring. Turning off low battery monitoring because you don't like it telling you there is a problem is like leaving the multimeter home because last time you used it, it showed that you had to change battery. Well quite a strange concept.

Enough on this subject from me. Back to the Port[:p]


Rob

[greerdr]

I have started using a "load-tester" to test my batteries. Unlike a multimeter it also reads out what power is availble under load,which is where I think Rob was going with his battery testing comment.I also have a RMG "flash" in the boat that also gives me a sense of security at a glance without disconnecting the battery.
The "Sentry" is available from Windjammin,a supplier on our EC-12 site.

R.C.Greer

[Rob Guyatt]

Hi Bob,
I had a look at the Sentry. Great little device to have in the kit.

As you have a Flash, you can load test your battery and ALL the wiring in your boat very simply. First I'll explain how the Flash samples voltage. As you can see, it has a display cycle of approximately 2 seconds. But what you can't see is that it is continuously sampling voltage during that cycle. It stores the first sample in the cycle then if it subsequently finds a lower sample that replaces the previous low read. So what you see is the lowest reading during that previous cycle. At the end of the cycle (after display of the previous lowest sample) it resets so that process can start over.

To see how well your power supply system is coping with the load of winch and other servos, just whack the Tx control (one device at a time) back and forth. While there may be no wind load on the winch at the time, you are making the winch (and other servos) demand starting current as you change directions. Starting current is the same as stall current but it is only for a very short time.

The beauty of this is that the test is a real test on your entire system not just the battery itself.




Rob

[greerdr]

Sweet!
The accolades heaped upon on the RMG are never enough.
Thanks for your unending efforts to make a superior product better.


R.C.Greer

[Rob Guyatt]

Knock it off Bob. You're making me blush.[:I]

but thanks anyway. we aims to please [:D]

I must put together a table of voltage drops as seen from the Flash for various battery pack and winches and servos so there's a guide to what should be expected. Still looking for that elusive supply of roundtoits but.

Rob