Product idea: asymmetric backup power switch

Hi,

These days many ESCs are providing a powerful BEC output which is usually very reliable.
But still people are interested in having a plan B in case of a BEC failure (or a loss of the main battery).
There are some devices available like the OptiPower Ultra Guard but still using this system with modern RC-systems is a bit tricky to me.
I still dream of a asymmetric Power switch with backup as shown on the picture below:


Battery 1 one could be a HV BEC (I guess it makes no sense to waste any thought on old LV systems) with approx 7.4 to 8.4 V supply.
Battery 2 is just a small backup battery. I think a LiFePo is most useful as they are not as "dangerous" like others and can remain in the model while Battery 1 will be charged after use.
The Switch will turn on and off the unit similar to the CB200. The standby power supply is done through battery 2. Power consumption and voltages can be monitored through Telemetry similar to the CB200.
In regular operation Battery1 is actively switched to the output and acts as the main supply. In addition it will charge battery 2 to keep it at approx. 90% charge level.

There are 2 cases when the backup battery will be switched to the output. In case of a massive BEC failure with the complete main battery voltage present at the BEC output and in case of a permanent BEC undervoltage. In general when the Battery 1 Voltage is higher than 9V and lower than 7V (or may be selectable by parameters).

This device would give perfect security with all BEC based power supplies.

Best regards
Onki

+1

+1, perfect.
Or / and integrate the logic above in the new mezon Controllers.

Best regards
Jochen

+1

Ich hoffe nicht, dass hier nur in Englisch geschrieben wird?

Aber eine "asymetrische Backup-Weiche" mit BEC-Versorgung und kleinem Pufferakku ist nicht das Problem.
Ich verwende z. B. eine Schaltung mit dem Low Loss PowerPath Controller LTC4412 + P-MOSFET's. Der Vorteil ist hierbei, dass fast kein Spannungsabfall entsteht.
Ein Ein/Aus Schalter o. ä. habe ich zwar nicht eingebaut, stellt aber auch keine Hürde da.
Will man allerdings den Akku im Betrieb laden, sollte dieser eine kleinere Spannungslage haben als das BEC und wenigstens eine Strombegrenzung vorhanden sein. Besser wäre hier eine einigermaßen intelligente Ladeschaltung bzw. Überwachung.
Das klingt aber interessant. Muss ich mir mal genauer ansehen.

Gruß
Peter