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Dort steht 10mA Ruhestrom (Alpha 21). Bei Dir sind es aber 69,5mA. Da scheint tatsächlich der Booster 59,5mA zu verbraten. Theoretisch müssten 5.000mA für ca. 450 Stunden Standby reichen. Die Kombination 5V-Powerbank und Booster ist auch keine gute Lösung, da geht viel Energie verloren.

It says 10mA quiescent current (alpha 21). With you it is 69.5mA. The booster actually seems to be wasting 59.5mA. Theoretically, 5,000mA should be enough for around 450 hours of standby. The combination of 5V power bank and booster is not a good solution either, as a lot of energy is lost.

SRB22 hat geschrieben: ↑Sa Aug 27, 2022 7:30 pm Could you give more details about your setup? AFAIK even the alpha22 user manual doesn't mention this...

Anbei der angepasste Schaltplan. Beschreibung nur auf Deutsch verfügbar. Mit freundlicher Genehmigung von Velorian.
Attached is the modified circuit diagram. Description only available in German. With kind approval of Velorian.

mumpel hat geschrieben: ↑Sa Aug 27, 2022 8:53 pm viewtopic.php?t=35

It says 10mA quiescent current (alpha 21). With you it is 69.5mA. The booster actually seems to be wasting 59.5mA. Theoretically, 5,000mA should be enough for around 450 hours of standby. The combination of 5V power bank and booster is not a good solution either, as a lot of energy is lost.

Thanks for the link! I was quite sure I had seen this information somewhere but was unable to find it again!

I'm in no way a specialist, but I think your calculation isn't right. AFAIK the mAh mentioned on a powerbank refer to the internal voltage of the cells, which is around 3.5V. So 5'000mAh * 3.5V = 17'500mWh. That would correspond to only 1'450mAh at 12V with an ideal booster, so around 145h of standby. Now throw in a 75% efficiency (?) for the booster, and the fact that you don't want the battery to go under 10%, that's around 92h of standby, so slightly less than 4 days.

That's not too far away from what I experimented.

So the powerbank + booster is definitely inefficient, but not nearly as bad as you describe. It's also a very cheap solution, so it might still be a reasonable one if I solve the standby problem.

mumpel hat geschrieben: ↑So Aug 28, 2022 12:13 am Attached is the modified circuit diagram. Description only available in German. With kind approval of Velorian.

Thanks! After a quick look, I'm not sure there's anything alpha22-specific in it, I think it might work with the alpha21 too. But I'd need to have a closer look to be sure I didn't miss anything.

What hardware do you use for the "Kombi-Blinker"? I was not aware it even existed!

Combination indicators (3in1) do not work on the Alpha 21.

What hardware do you use for the "Kombi-Blinker"? I was not aware it even existed!

The Velorian Alpha 22 and combination indicators from the motorcycle trade (https://www.toxx-motorsport.de/blinker/ ... toent?c=63). For the brake light I use reed switches (https://windmeile.com/shop/e-bike-teile ... nsor-2-stk ) and magnets (https://www.mtsmagnete.de/neodym-scheib ... 5mm/a-2504). The magnets are glued to the brake levers at the required distance from the magnetic sensors, the magnetic sensors are glued to a suitable place on the brake handle (https://www.pedelecforum.de/forum/index ... st-1391932).

Nice hardware, thanks for the links!

SRB22 hat geschrieben: ↑So Aug 28, 2022 5:59 pm
I'm in no way a specialist, but I think your calculation isn't right. AFAIK the mAh mentioned on a powerbank refer to the internal voltage of the cells, which is around 3.5V. So 5'000mAh * 3.5V = 17'500mWh.

As far as I know, the decisive factor is the ampere hours. My Bosch e-bike battery delivers 16.7 ampere hours. This means that the battery can deliver 1A (1000mA) for 16.7 hours per hour. The indicator box only requires 10mA (0,12 Watts by 12V), i.e. 1/100 of 1000. This results in a calculated runtime of 1670 hours with quiescent current. Power loss, end-of-discharge voltage and consumption of the control unit and voltage converter are not taken into account (the DC-DC converter converts the 48 volts of the battery into 12 volts).

Another example:
A 2600mAh battery and a 20mA LED.
2600mAh/20mA = 130 hours

The consumption (in mA) always refers to one hour.

Your examples are correct *if* the voltage is the same everywhere. But mAh don't tell much if you don't know the voltage.

If mAh where all that counts, I could replace my 20Ah @ 52V battery (5kg+) with an USB powerbank of 20Ah @ 3.7V (less than 400g). I wish I could, but unfortunately it wouldn't work.

20Ah @ 3.7V is only 1.4Ah @ 52V (supposing a transformation without loss) so I would only ride a few kilometers.

But I guess we are drifting away from the thread initial subject

With e-bikes, you usually have 12V for accessories. If you connect 6V accessories, and these can sensibly convert the 12V, you theoretically have twice the runtime. But simply exchange your Alpha 21 for the Alpha 22, which probably only needs 7mA. Your bike shop may be able to help you.

SRB22 hat geschrieben: ↑Fr Aug 26, 2022 6:42 pm - What would be the gain of switching from an alpha21 to an alpha22? what are the standby power of each system? would that be a significant improvement?

The quiescent current of the alpha22 is only 0.8 mA compared to the 10 mA of the alpha 21.
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Der Ruhestrom der Alpha22 beträgt nur noch 0,8 mA im Vergleich zu den 10 mA der alpha 21.

SRB22 hat geschrieben: ↑Fr Aug 26, 2022 6:42 pm - Routing and soldering cables took time, I'm not very enthusiastic at the thought of doing it all over again. Would it be feasible to just replace the box, leaving all cables in place? how hard would that be to open the boxes and replace all the cables?

The indicator box can be opened with a T6 Torx bit and the electronic board can be changed. The 3 cables are identical to those of the alpha21.

When disconnecting the cables, make sure that all plugs are inserted with a lock. If you press on the upper end of the plug, the lock opens and the plug simply slips out. This is a little tricky with the 2-wire plug, but can be done with a little patience and sensitivity. You should hear a soft click when you plug it in.

When inserting the circuit board, pay attention to the sealing rubber around the sound generator and the correct insertion of the cables!
First push the sound generator into the sealing ring and then insert the circuit board.

The box has a built-in strain relief, but it only works if the cables are inserted far enough (approx. 5mm).
The cables tend to get caught in the screw domes or in the edges. That is why it is important to do a final check when closing the box before inserting and tightening the screws.

When inserting the other two cables, make sure that the 2-wire cable of the power supply is on the outside and the 4-wire cable is on the inside (towards the sound generator).

Do not tighten the screws too much, otherwise the plastic will give way and the thread will be gone. If this happens, a new housing is needed.

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Die Blinkerbox kann mit einen T6 Torx Bit geöffnet und die Elektronik-Platine gewechselt werden. Die 3 Kabel sind identisch mit denen der alpha21.

Beim Lösen der Kabel darauf achten, dass alle Stecker mit einer Verriegelung eingesteckt sind. Wenn man auf das obere Ende des Steckers drückt, wird die Verriegelung geöffnet und der Stecker rutscht einfach heraus. Das ist beim 2adrigen Stecker etwas haklig, aber mit etwas Geduld und Feingefühl machbar. Beim Einstecken sollte ein leises Klick zu hören sein.

Beim Einsetzen der Platine ist der Dichtungsgummi um den Tongeber und das korrekte Einlegen der Kabel zu beachten!
Zuerst den Tongeber in den Dichtungsring schieben und dann die Platine einsetzen.

Die Box hat eine eingebaute Zugentlastung, die greift aber nur, wenn die Kabel weit genug (ca. 5mm) eingelegt werden.
Die Kabel legen sich gern in die Schraubdome oder in die Ränder. Darum ist der letzte Check beim Schließen wichtig, bevor man die Schrauben einsetzt und festschraubt.

Beim Einlegen der beiden anderen Kabel darauf achten, dass das 2adrige Kabel der Stromversorgung außen liegt und das 4adrige Kabel innen (zum Tongeber hin).

Die Schrauben nicht zu fest anziehen, sonst gibt das Plastik nach und das Gewinde ist dahin. Falls das doch passiert, muss ein neues Gehäuse her.

Viele Grüße
Eckehard