Jump to content

Narrowband

Dew Heaters And Batteries


Recommended Posts

I’m trying to power a couple of 5v USB dew heaters. Obviously the amp draw is too much to power through a standard USB hub and I’d rather not use a wall adapter because I don’t want a birds nest a cables to deal with. If I power them through a Power Bank would I be able to get away with one or would I need one for each heater?  I’ve seen plenty advertised as putting out 2.4amps but it’s never really clear if that’s per device or in total split between devices. Also how much charge time could I expect from a 20,000 mah battery? Will I be able to get a full night out of it?

Link to comment
Share on other sites

Powerbanks are at best economical with the truth.

If they quote 20Ah (20000mAh sounds more to folks who don't understand) they mean the cell capacity.
There is a 3.7V(ish) cell that is 20Ah. This equates to 20 x 3.7 = 74Watt hours (Wh).

You then have a circuit to step up to 5V, which is never 100% efficient. Lets assume 80% efficiency.
So your 74Wh becomes 74 x 0.8 = 59Wh.

This can be expressed as 5V, approximately 12Ah.

In other  words, a 1 amp dew heater for 12 hours, 2 amps for 6 hours, 3 amps for 4 hours, etc.

Now you need to look at the rating of each dew heater to establish total run time.

HTH, David.

Link to comment
Share on other sites

That’s the sort of thing I need. As long as it doesn’t use QC3.0 it would probably be ideal. Also after a bit of searching I see Pegasus Astro do a USB hub with 6 ports providing 2.5 amps each. It’s £168 though. But it would solve a lot of potential headaches. 

Link to comment
Share on other sites

Would something like this do the job - it does at our home for phone and iPad charging. Claims 12 Amps overall if using multiple ports.

https://www.amazon.co.uk/Anker-PowerPort-Family-Sized-Technology-Smartphones-Black/dp/B00PK1IIJY/ref=sr_1_1?crid=3PLEGLR33V605&keywords=anker%2B6%2Bport%2Busb%2Bcharger&qid=1666437082&qu=eyJxc2MiOiIyLjIzIiwicXNhIjoiMS41MCIsInFzcCI6IjEuNTcifQ%3D%3D&sprefix=anker%2B6-port%2Busb%2Caps%2C92&sr=8-1&th=1

Or if you own Makita LXT 18V power tools then this might work also.

https://www.amazon.co.uk/Makita-DEBADPP05-14-4-Li-Ion-Adapter/dp/B019WI5XXO

 

 

 

Edited by Jules Tohpipi
Link to comment
Share on other sites

23 minutes ago, Jules Tohpipi said:

Might order one and give it a try. It’s the whole quick charge thing that could cause a problem though. They use Chips from Qualcomm that negotiate with the device plugged into it to establish how much power to deliver. The controllers on the dew straps are just dumb devices so the charger might fall back to the basic USB spec which is 0.5 amps. But at least with Amazon it’s easy to return it. Worth a try. 
 

i did think about knocking up a couple of 12v controllers with some 555 chips I got. But I’m guessing the wires in the straps would have a different resistance to those used in 12v straps?

Link to comment
Share on other sites

19 minutes ago, Vallantho said:

Might order one and give it a try. It’s the whole quick charge thing that could cause a problem though. They use Chips from Qualcomm that negotiate with the device plugged into it to establish how much power to deliver. The controllers on the dew straps are just dumb devices so the charger might fall back to the basic USB spec which is 0.5 amps. But at least with Amazon it’s easy to return it. Worth a try. 
 

i did think about knocking up a couple of 12v controllers with some 555 chips I got. But I’m guessing the wires in the straps would have a different resistance to those used in 12v straps?

Should be fine in that regard - if I've understood the technicalities correctly (possibly not). We have two of this exact model running at home - charging some ancient devices ocassionally - and certainly they charge much faster than default 0.5A.

Link to comment
Share on other sites

3 minutes ago, Jules Tohpipi said:

Should be fine in that regard - if I've understood the technicalities correctly (possibly not). We have two of this exact model running at home - charging some ancient devices ocassionally - and certainly they charge much faster than default 0.5A.


Yeah I’m just gonna order one and see how it goes and there’s more than enough sockets for dew straps, raspberry pi and anything else. Should help keep the spaghetti under control. Thanks for the heads up 👍👍

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.