maestro internal battery

Mark Erbaugh

I just got my Maestro back from a trip to Austin to be re-flashed after an unsuccessful attempt to upgrade to 1.8.4.  I was running it using  a USB battery. The indicator on the battery indicated about 60% when the Maestro displayed a message telling me that the internal battery was low and to plug in to DC.

This indicates to me that the internal battery does not recharge when using a USB battery. I purchased two USB batteries and my usage of the Maestro is virtually 100% on USB battery. Since the Maestro does not recharge the USB batteries (I understand the reason why), I saw no reason to ever pug the Maestro into DC, but it appears that this is not the case.

Did any of the alpha testers run the Maestro exclusively on USB batteries to verify that the internal battery is being charged in this scenario?

Also, this is just anecdotal at this time, but it seems that my 5 GHz wireless connection is more reliable when running off of DC than from the USB battery. Granted, I moved a few feet to be closer to a wall outlet, but when I was running of the USB battery, the LAN indicator was constantly fluctuating and there were minor audio drop outs. After getting the low internal battery message and plugging in the Flex AC/DC adapter, the LAN indicator was constantly 5 bars all green. Is there any difference in WiFi operation on DC versus on the USB battery?

Tim - W4TME

So let me address your questions.

I was running it using  a USB battery. The indicator on the battery indicated about 60% when the Maestro displayed a message telling me that the internal battery was low and to plug in to DC.
This indicates to me that the internal battery does not recharge when using a USB battery. 

That is an invalid assumption.  The internal battery is charged if you are running on DC power or by a battery bank that meets certain requirements.  You will get this error message when the internal battery charge drops while operating the Maestro.  There are several ways this can happen.  If the battery power bank is not providing a full 5 VDC output, then the internal battery will not charge and will begin slowly discharging.  I suspect that is happening, particularly if you are using a Polanfo battery, as we have seen many of these batteries produce less than 5 VDC under load.

Did any of the alpha testers run the Maestro exclusively on USB batteries to verify that the internal battery is being charged in this scenario?

This was a well-tested use case.

Granted, I moved a few feet to be closer to a wall outlet, but when I was running of the USB battery, the LAN indicator was constantly fluctuating and there were minor audio drop outs. After getting the low internal battery message and plugging in the Flex AC/DC adapter, the LAN indicator was constantly 5 bars all green. Is there any difference in WiFi operation on DC versus on the USB battery?

No, there is no difference in wifi operation on DC versus on the battery bank.  As with the previous answer, the wifi operation will fluctuate if the supply voltage is below 5 VDC.  With 12 VDC power, a voltage regulator converts the higher source voltage to 5 VDC.  With a battery, there is no headroom available if the source voltage drops below 5 VDC.

Mark Erbaugh

Thank you for the information. I think it explains what I have seen. I am using the Polanfo batteries, as these were recommended on the forum as the Maestro was being released (I ordered my at Dayton on 2015). Is there a new recommendation for a battery that will work properly?

It seems like the USB batteries have been problematic. Flex was unable to come up with a charging circuit and now it seems that at least some of the USB batteries are really not up to the task of powering the Maestro. I've also seen some comments that the power supply inside some of these batteries create RFI.

Maybe hindsight is 20/20, but wouldn't it have been better to design the Maestro around a typical laptop style battery. Those can be recharged in even inexpensive laptops and the remaining capacity can be accurately monitored.

Tim - W4TME

Honestly, it is a bit of a **** shoot.  We see the low voltage issue more pronounced with the Polanfo batteries, but not all of them have an issue.  We have seen this behavior to a lesser degree with the Mogix batteries.  These are mass produced products that may not have the most stringent manufacturing QC processes.