Power bank for ASIAIR

tants

Hi,

Like to know more about ASIAIR Plus.
1) Any suggestion for the lithium-ion powerbank for the running the unit? I am thinking of those that can bring up to plane in the hand-carry luggage.
2) Will the ASIAIR Plus work without the antenna?

Regards.

w7ay

tants Will the ASIAIR Plus work without the antenna?

Yes, just connect the LAN connector of the ASIAIR directly to a router's LAN port with an Ethernet cable (or to an iPad using an Ethernet adapter).

Be sure to terminate the ASIAIR's antenna port with a proper 50 ohm termination after removing the antenna. Like this one:

https://www.amazon.com/gp/product/B0719C1T99

I am thinking of those that can bring up to plane in the hand-carry luggage.

Keep in mind that if you are using Lithium batteries, the FAA limits you to no more than 100 Wh on a passenger aircraft. That is why many Lithium power banks are rated for no more than 99 Wh. Budget your power accordingly.

Chen

WalterT

w7ay Be sure to terminate the ASIAIR's antenna port

Hi Chen, off topic but curious, what are the negative effects if you don’t do this. Also, would the same apply to my Mobi router that I’m using at the telescope if I don’t screw in its 4G antennas, should I terminate the 4G ports?

w7ay

WalterT what are the negative effects if you don’t do this.

If you don't terminate the antenna port while the radio's transmitter is active, the transmitter will see an infinite voltage standing wave ratio. That is the equivalent of shorting the port, which is something you should also never do.

https://en.wikipedia.org/wiki/Standing_wave_ratio

100% of the transmitted power will be reflected back into the power amplifier.

Chen

tants

Thanks for the advices.

I am wondering, with the current Power Bank that has PD3.0, how long will it last when it is rated at 10000mAH, and the ASIAIR is the only device connected to the powerbank?

Regards.

w7ay

tants how long will it last when it is rated at 10000mAH

Specs that use mAh are useless since they often refer to the power of the battery. Without knowing the voltage of the battery used, you have zero idea of how much energy you have available. (An internal LiPo battery can have 3.7 volts for example, and these are boosted to 12V.)

You want the mWh (milliwatt-hour) rating of the power bank. You can then add all the power used (in Watts), divide that into the rating, and get the maximum number of hours the power bank will last.

PD means "Power-Delivery," that uses the USB C connector to pass power, and requires the device end to be PD compliant to set the actual voltage (which can be 5V, 9V, 15V or 20V -- defaults to 5V). The PD compliant device (can be a smart phone, tablet, laptop, etc) handshakes with the PD power source to determine the voltage it needs. To use for anything that is not PD compliant, you need to use what is called a Power Delivery "decoy" or "trigger" to get the correct voltage out of the power bank. I.e., unless the power bank has either PowerPole or 5.5mm axial jacks, such a power bank is not usable by an ASIAIR unless you also buy a decoy with the proper voltage.

Chen

tants

Thanks, w7ay ,

1 more question, what is the impact if I am using a power bank with 12V output but max is 3A output?

I am looking for portability; the 12V 5A model size is having a lead acid battery size, just that it is not that heavy.

w7ay

tants impact if I am using a power bank with 12V output but max is 3A output?

That means it may barely work. That's just 36 watts of power. And that assumes the specifications is honest.

A slewing mount could eat 12 watts, your dew heaters are probably 8 or 10 watts each. Since we are in the ASIAIR thread, the ASIAIR's processor (not including I/O) will need some 10 to 20 watts.

Many small Lithium power banks are rated for energy limited to 99 Wh because of the US' FAA regulations (probably similar rules worldwide) has a limit of 100 Wh of energy. Above that, you can't ship by air, and can't take it on an airline with you (comes by ground transport when you order from Amazon).

Checked-in baggage (unattended in the cargo hold) has an even stricter regulation -- you can't check in stand-alone (not part of a device like a smart phone) Lithium batteries, period; power banks and spare batteries need to be in carry-on baggage.

With Lithium, be sure to pick reputable companies. When the Lithium batteries explode, they explode in a spectacular fashion, and hard to extinguish (look at the exploding Tesla cars that takes days for firemen to tame). If you can, pick LiFePO4 variety instead of the Li-Ion variety. The LiFePO4 ones are inherently much more stable.

Sealed Lead Acid are of course the most stable. Be sure to keep them charged so that they don't sulfurate. But you can get small 7A ones (not that heavy), i.e., about 84 Wh. If you run 30 watts of power, they will last more than 2 hours. The SLA power curve is not great (they droop early), so you may also need a boost converter to keep the voltage constant at 12V.

There are pros and cons for everything, especially with safety concerns. That being said, I do own two larger power banks, a Lithium Ion at 320 Wh, and a LiFEPO4 bank at 160 Wh, but I use them extra carefully. I use a 7 Ah SLA battery for the uninterruptible power supply for my mount -- it is constantly trickle charged even when not in use, and I feel completely safe with it even unattended.

Chen

tants

Thanks for the patient and knowledge sharing, Chen.

Basically, I will to get the ASIAIR, and it will be mainly used for polar alignment. My residential place is very near to the equator and always cloudy/have a thin layer of mist. Hence, it is of not much use.

When I travel, I will need to adhere to carry-on luggage restriction, which is usually 10kg. With my lens and camera, it is already closed to 10kg. Be it SLA or Lithium-ion, they can only be in the carry-on luggage. Therefore, I am looking at smaller version of the Lithium-ion battery which is lighter.

I guess I will have to do further hunting/research for the right battery so that I can proceed with the astrophotography shooting.

w7ay

tants Be it SLA or Lithium-ion, they can only be in the carry-on luggage.

By the way, in the US, although the FAA regulation stupilates that you can only bring Lithium as carry-on (no cargo hold), and that the battery can only be no more tha 100 Wh, you are allow two packs; considered power banks to recharge your devices. (Probably because of long international flights -- I guess they never heard of the Apple Silicon that is very power efficient, ha ha.)

So, you can bring 200 Wh worth in the US, just has to be two different 100 Wh ones.

I don't know about other countries, but ICAO tends to follow FAA, and other countries tend to follow ICAO.

When you travel, do you also rent a car? If so, that is your solution.

The 12V outlets of cars tend to be standard -- however, just to make sure none of your equipment blows up (a fully charged SLA is 13.8V and an alternator can put out more than 14 volts, and at the same time, the battery can droop quite low). So equip yourself with a buck/boost regulator. You can find lots at Amazon. Find one that will put out 12V while the input (the car) varies between 11 and 18 volts.

I used to (in the late 1960s and early 1970s) drive a VW Karman Ghia, and it used a 6V battery. And then there were British cars back then that used positive ground (the chassis is positive). But those days are long gone, fortunately. Just don't rent a vintage VW, MG or Austin :-).

connecting as 3S2P, so that it can come up to 12V supply

By the way, you can use buck/boost regulators to boost the 18650 too, if you cannot get close to 12V otherwise. In fact, my LiFEPO4 bank came with a buck/boost regulator that looks like a generic buck/boost regulator from Amazon :-).

But, be careful about DIY batteries which you have to prove to airports that you are within energy limits, and have the proper protection circuits. I think it is safer to buy an off-the-shelf power bank where all the information is printed on the power bank. You don't want to kill your fellow passengers, in any case.

Please be careful playing with Lithium batteries.

Chen

tants

Just to add on, I am thinking of building my own battery pack using 18650 batteries, connecting as 3S2P, so that it can come up to _12V supply and if using higher capacity batterys, _3500mAh, I may be able to achieve 7Ah. Just that I need to ensure that the Battery Management System can support 5A output.