receiver battery

[ashley needhamParticipant @ashleyneedham69188]

Our man Trevor is a clever fellow, and to power his latest aquisition, a smallish sailing vessel, he has used a power pack, of the sort used to provide additional power for a mobile phone etc.

These things are quite compact, are USB chargeable, have a USB outlet (or a mini USB socket.

The thing is, they dish out 5V, perfect for our application, and can come is anything from 1000 to 3000 mAh, and have an output of 1A or so. Trevor only needs Receiver and two small servos to be powered, and his power bank cost a fiver.

You need to simply connect the two power pins on the USB to a servo plug, an easy if a bit fiddly job, and there we are. Saves messing about with a 4xAA pack.???

Ashley

[ashley needhamParticipant @ashleyneedham69188]

[Chris EParticipant @chrise]

Great idea.

I am not sure where you can buy one that I would trust for £5 however.

[Dave ReedParticipant @davereed72029]

At the more basic end of the scale is the single call 18650 version. Pictured below dressed, undressed and 18650 cell

The clever bit is the tiny PCB that provides charging for the cell and 5v output for your device. Now if you can follow my strange thought pattern for a while…..

Similar PCB's (without charging regulator) are available in a wide range from the likes of ebay and amazon very cheaply. They're often referred to as Buck-Boost or DC to DC converters. If we stick with 5v output to supply receiver and servo's, and you have a spare battery pack from about 1v to 24v you should be able to find one of these PCB's to suit your pack. In effect, it's a dedicated BEC.

Then again, it's going to be easier to just use a complete power pack (or a 4 AA pack). I might be over-thinking this one a bit but I do like looking for alternative solutions.

Dave

PS – In fact I seem to be taking something simple and making it complicated, too much coffee this afternoon.

[Colin BishopModerator @colinbishop34627]

As Chris says, £5 seems a bit on the low side price wise. Currys have a 5000MAh cut price one on sale for £7.99.

Personally I like to stick with AA cells, especially the low self discharge variety which hold their charge for a long time such as these:

**LINK**

Tried and tested!

Colin

[Chris EParticipant @chrise]

The big advantage of a 18650 powered pack has to be the lack of weight. A 3000mah 18650 pack should not weigh more than 50g whilst Colins AA pack weighs 118gms. The difference clearly doesn't matter for most purposes but could be critical for others.

[Dave ReedParticipant @davereed72029]

As Chris mentions weight:

The 18650 pack pictured above weighs 49g when removed from the metal cylinder. With the cylinder it's 70g. Its quoted capacity is 2200mAh.

Edited By Dave Reed on 05/03/2023 22:16:40

[ashley needhamParticipant @ashleyneedham69188]

I mentioned it for the convenience really. In-car charging, charging off the laptop/computer all easy. Make a couple of USB/Rx plug leads and jobs a good’un. Light and compact.

Poundland used to do them, 1300mAhr. A cheap one may not have a supposed 2600 capacity, but surely it will have at least half that, more than enough.

I looked at the 18650 batteries as for possible lower power boat usage but the extra faff did not seem to offer any advantage over Lipos or whatever, given the ready connectors and chargers. As I understand it, these batteries are very common in a lot of usb powered devices, and make up battery packs for laptops and stuff.

For very small or plastic magic conversions, just the job as the voltage should stay high even under load and there is the compactness of a single unit.

Ashley

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