R2 Power consumption

[dongle]

Hi,

Anyone interested in running the R2 from a battery pack may like to know these figures:

R2 connected to 5V power supply...7 mA
R2 "ON" .......................................350 mA
R2 "Record".................................. 480 mA

The consumption may vary between units but I doubt it will be very much. I used a 1GB compact flash card for storage and the highest video settings.

Adding a camera and an 8GB card for long recordings makes the power consumption significant for "portable" applications.

Cheers

[bobkart]

Great information dongle.  I just ordered a 56Wh battery pack for my R2, so at 2.5W that's over 20 hours recording time.

[dongle]

Glad to be of service.

You will no doubt be aware that the quoted capacity and actual capacity are rarely equal and is also dependant on operating temperature. However in temperate climates this is not something to worry about. Also the battery voltage will reduce according to the discharge rate and there will come a point when it will fall quite sharply as it becomes exhausted. This is a dangerous time for equipment (such as the R2) that does not have input voltage sensing that shuts off the unit when the input voltage falls below a certain point - probably around 4V.

A good quality battery pack should have this functionality built in. Another thing to consider is what happens to the current recording should the battery discharge.

I guess my point is to keep the battey fully charged when possible and keep an eye on the remaining battery level.

[bobkart]

Good advice of course.  I rounded down from 22+ "theoretical" hours with that 20-hour estimate.  Trying to get all 20+ hours in a row compared to on-and-off usage is another way to me up short.  That's why they will often quote amp-hour ratings based on some some period such as 10 hours.

And I do suspect it is a good quality battery back, if only based on the price I paid:

http://www.tigerdirect.com/applications/searchtools/item-Details.asp?EdpNo=2240427&sku=T120-1026

I may consider monitoring it with a dummy load as it gets low the first time to see how it deals with the "end of charge" situation you describe (if it's not covered in the User Manual).

[dongle]

Looks like a nice device, the indicators on the top for remaining capacity will help and I would be interested to hear how your test goes.

[bobkart]

I'll certainly report my findings here, although that may have to wait until Neuros swaps my R2 out with one that doesn't have hosed audio.

I think the LEDs across the top are for selecting/indicating the output voltage, although they may double as capacity indicators.

[bobkart]

Yes the 8 LEDs acrosss the top double as battery level indicators.  So far I've recorded over an hour's worth of video and have yet to see anything but full power levels from the gauge.  This is with the MP3400 with 56WH specified, compared to the 40WH of the smaller, MP3300 model.  56WH is about 11AH at the 5V level.  It actually puts out about 5.2V, almost exactly what the Neuros-supplied AC adapter puts out.

[dongle]

Thanks for the feedback.

[TeeJay]

A little help/explanations required

I am looking for a more universally useable external power supply
My idea is to use a battery holder that will take 8 x AA batteries each at 2300ah and connect them up in paralel as two sets of four effectively creating a 5v 4.6ah supply, I know the quoted battery ah ratings are going to be over the top and I'm assuming in reality that they are only about a true 1.8ah each which will give 3.6ah at 5v

Any idea how long the unit will last on a 3.6ah supply ?

The reason I am looking at this way is that I intend to retail the R2 and I don't want to bundle expensive PSUs or force customers to have to buy them, AA batteries and chargers are universally available and most people already have them

[dongle]

Connecting batteries in parallel is fine so long as they are in the same state of charge. You would need to ensure that either both sets are charged one after the other, simultaneously in a charger capable of taking 8 cells or using two chargers.  I would look at using C cells instead. 4xC is the same volume as 8xAA - ish... C cell capacity can be up to 4.5Ah or perhaps greater, check the market. Of course you could always use D cells... Charging time for larger cells may be an issue.

Under load:
Fresh alkalines will give a terminal voltage of around 1.5V so 4x = 6.0V.
Charged NIMH cells give a terminal voltage of 1.2V so 4x = 4.8V

Both types will do the job but the discharge curves will be different. The NIMH cell has a "flatter " discharge curve so will provide the correct voltage for longer (perhaps...) but the alkaline cell starts with a higher voltage.

We know that the R2 regulator will not be happy at 4.4V so you have to ensure that customers only use freshly charged cells and that they keep an eye on the battery voltage. Naturally this will not be popular which is why you need to consider a battery pack with a integrated 5V regulator. There are a few on the market and several have been mentioned in this forum.

To calculate the length of time a battery will provide sufficient voltage requires the use of discharge curves and a knowledge of the current required. Unfortunately you cannot just divide the capacity by the load requirement however if you are prepared to assume a worst case of 50% capacity then this will give a starting point.

So (eventually...) 3.6Ah = 3600 mAh divide by 500mA (R2 recording) = 7.2 hours

[TeeJay]

Many thanks for that Dongle
Given your information the idea I had should be OK as the marktplace I'm aiming at is enduro/off road motorcycling
It's very rare that anyone rides in that enviroment for more than 2 hours continuously, I may still look at the power pack options though but I'd really like a 12v for the camera and 5v for the Neuros, damned shame they don't both run off the same voltage as it'd be far less hassle for the end user to have one single power supply with two outlets, far less wiring and only one unit to charge up

[bobkart]

Any idea how long the unit will last on a 3.6ah supply ?

I measured the current draw on my R2 with a SanDisk Ultra II 1.0GB Flash Card inserted:

Off: 0.02-0.03A
On: 0.32-0.33A
Rec: 0.44-0.45A

So a simple division yields (using the higher numbers):

Off: 3.6AH / 0.03A = 120 Hours
On: 3.6AH / 0.33A = 10.9 Hours
Rec: 3.6AH / 0.45A = 8 Hours

[dongle]

Let us know how the system performs in real world tests.

I doubt that Neuros expected the Rx to be quite so popular in applications away from the mains socket. This is a real shame because they made decisions that have hindered many projects. There is a way of getting round the problems but it is all extra hassle and people start looking round for a simple solution.

I would have liked to see:

Power indicator
Mechanical power switch
Mainstream remote control instead of the little used NEC protocol.
LANC or similar for wired control
Wide supply voltage regulator up to about 18V

Ironic that there was a USB connector on the R1 - perfect for serial control from an external unit. This has reappeared in the OSD but the unit is physically larger.

Can't win !