Power by Li-Po power pack or other high mah supply

Submitted by Stian on Sat, 07/30/2016 - 20:33

Forums:

Hi.

I'm new to electronics and embarking on an ambitious learning project to create a quadcopter or drone. I think connecting the ZeroBorg to a 9V battery will only provide < 15 mins of flight so I am seeking another options. I see some alternative options:

  • Use a 7.4V Li-Po power pack to power everything via the ZeroBorg
  • Use a 5V mobile power bank. I think then the pack would need to power the ZeroBorg and PiZero separately... which consequently means I must modify the 6 pin I2C connector provided with ZeroBorg to not provide power to the PiZero (or I can just use individual jumper cables).

Does anyone have any experience using ZeroBorg in this way?
Are there other power configurations I am not seeing?

Best,
Stian

piborg's picture

piborg

Mon, 08/01/2016 - 10:30

Using a Li-ion / LiPo is an option, but there are some things to be aware of:

  • They require special chargers
  • Be very careful not to drop or pierce them!
  • Make sure you do not overcharge them
  • They do not like being run completely flat

In short you can, but we recommend that you are very careful with them as they are much more dangerous then NiMH and NiCad rechargeables.

What you will care about the most for run-time is the total power the battery holds.
This can be worked out by multiplying the voltage of the battery by it's current capacity: mWh = V × mAh

For a typical "9V" style rechargeable this is typically:
8.4 V × 150 mAh = 1,260 mWh

For a power bank of say 1,000 mAh this looks pretty good:
5 V × 1,000 mAh = 5,000 mWh
The trouble here is the 4× running length comes at the cost of reduced voltage output.
If your motors want more than 5V they may not run fast enough like this.

As an alternative you can get high capacity rechargeables in the 9V package:
https://www.tantronics.co.uk/powerex-300-mah-pp3-nimh-rechargeable-batte...
This will run about twice as long if that is enough for your needs.

Finally you can connect two or more of the 9V style batteries in parallel to increase the running time.
The simplest way to do this is fit one battery directly to the board and a second via a 9V clip to the V+ and GND screw terminals.

spacedementia87

Fri, 11/08/2019 - 14:12

I have bought some 9.6V powerex pp3 batteries, however they don't seem to be detected when i plug them into my nimh charger.

Can you recommend a decent, working charger?

piborg's picture

piborg

Fri, 11/08/2019 - 20:20

We use a Powerex MH-C1090F charger which has worked reliably for us. It takes about 3-4 hours to charge a 300 mAh battery.

From memory there is a smaller version of the charger which takes 4 batteries instead of 10 :)

spacedementia87

Fri, 11/08/2019 - 21:47

Yes, I saw that one, but I don't seem to be able to find a UK supplier!

piborg's picture

piborg

Sat, 11/09/2019 - 20:49

This looks like a UK distributor for the chargers: https://www.mahaenergy.co.uk/products/battery-chargers/008-maha-c490f-4-...

Stian

Thu, 08/11/2016 - 00:16

Thanks for that really helpful answer!

The power bank option did sound too good to be true. I should probably build this in stage and complete an initial build with a single 300mah 9V battery. Adding a second battery via a clip sounds like a straight forward enhancement, thanks for pointing that out!

Best,
Stian

Stian

Sun, 10/09/2016 - 15:28

Curious if the ZeroBorg would handle a 3S LiPo battery?
i.e. 11.1V, not 10.8V as the per the ZeroBorg spec.

piborg's picture

piborg

Tue, 10/11/2016 - 13:20

Unfortunately I cannot guarantee that the ZeroBorg will be fine with this.

Put simply the chips we have used will be able to cope with at least 10.8 V.
They may or may not cope with a slightly higher voltage.

You can either:

  1. Play it safe and stick within the 10.8 V margin
  2. Take a risk and see if your ZeroBorg works with the higher voltage

I would say there is a 50/50 chance of the ZeroBorg being perfectly fine.
The problem is that if it is not it will probably cause permanent damage to the ZeroBorg and possibly anything connected.

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