Maestro scare

Bob G W1GLV

This AM I was operating the Maestro when all of a sudden lights and display on the Maestro started flashing randomly. All I could think of was a trip back to FRS. The culprit was the battery was going dead but the the battery indicator showed a full charge. I thought that was kind of weird since the Maestro was on battery power for about 6 hours. Plugging the unit into the supplied wall wart got it back to normal operation.

K6OZY

The battery icon is not a "fuel gauge" battery indicator. It simply shows you that Maestro detects a USB battery. Remember, these batteries always present a constant voltage of ~5-5.2V, so there is no way for Maestro to know the charge state of that USB battery.

KD3VK Ken

Ok, so how do our cell phones and all things like that that use these Li batteries (including the backup/recharge aftermarket cells) show us level of charge?

Tim - W4TME

These devices have specialized batteries manufactured specifically for the devices which contains the proper monitoring circuitry for reading charge level.  

Bob - W7KWS -

The cell phone batteries are just that, a battery & a charge control circuit. My USB battery for Maestro has a boost regulator which maintains a constant voltage output until the thing is exausted. That's why Maestro is unable to detect the state of charge. Comparing two completely different products to draw an answer is a trap one should avoid.

KD3VK Ken

Makes sense, thanks Tim.

Eric-KE5DTO

I have noted that when the battery dies, sometimes the battery indicator stays up for some time.  I have added an issue (#3625) to address this to help give a quicker indication that the battery has lost voltage.  Thanks for the report.

Unfortunately, I have to agree with the others that the output of these power packs is regulated such that you have no direct visibility into the remaining battery life until it simply quits supplying voltage.  This is likely why most of these products have external indicators to show how much charge is left.

Eric-KE5DTO

I think it is all about where the voltage regulators are relative to the monitoring.  If you can monitor prior to the regulator, this gives you visibility into the actual battery voltage and this would be a good indicator of remaining charge.  This is the case with things like your cell phone and these power packs.  The output is past this point in the circuit though, so we simply don't have that kind of visibility.

Jay -- N0FB

Bob,

What you describe looks to be what happened to Gerald when demonstrating the Maestro at the Greater Houston Hamfest.   If you watch the below, at the 1:31point in the video, you will see the battery likely give up the ghost and the buttons start flashing erratically.  Gerald does a great job and simply moves on to demonstrating the 1500.  He doesn't get shaken up at all.  This is obviously not his first rodeo. ;-)


https://www.youtube.com/watch?v=wQFgRzji4nA

Ken - NM9P

I noticed that as well when this video was first released...skillfully done.

Bob G W1GLV

Jay, that's exactly what happened to me. Now we know.

tartanlatte

This should at a very minimum be documented in the battery section. I had the same issue tonight and was freaked out after using mine for 3 hours. I likewise assumed that the battery indicator was a charge level indicator. A simple paragraph in the battery section and/or the troubleshooting section would help customers.

G8ZPX

Hm, a battery powered device with no way to monitor the battery state. Way to go!

Steve K9ZW

@Steven - there is probably a patent or two and a good income for someone who can measure battery state through the voltage regulating circuitry (with all sort of variations) in these LiPO booster battery packs.

The circuitry is specifically designed to present a constant state to the powered device, which completely masks the battery's actual state until drop off as the last stages of discharge.

Some have LEDs on the packs, some other schemes, but even those are considered rough indicators and not monitors.

Since you have a reasonable hot-swap time the impact is not horrible.

Another alternative is to use a completely external pack with enough capacity to outlast your entire planned operating time.

But to be clear the shortfall is one FRS has no way of resolving effectively if LiPOs are to be used.

73

Steve K9ZW