Charging a vhf radio from a lithium power bank

[Nismosteve]

I have a Standard Horizon HX 870 marine radio. It has a mains charging dock for the lithium battery pack. Also a car charging plug is supplied as well, for the dock. It can be powered at 1W by an adapter that takes 5 AA batteries. Okay for recieving but limited for transmitting. I have been considering a lithium power bank and a usb to ciglighter socket, to enable charging on multiday trips. This is a dsc radio so battery life is reasonable for day trips. Anyone ever used a combination like this for charging their radio.?

[Chris Bolton]

I would check the current required by the charging dock, and see if the USB boost converter can supply enough. You may find that the converter is inefficient at higher current. It might be better to find a 12v power bank. There's a recent thread about using car starter packs for a pump, may not be good for that but could be good for charging.

[Nismosteve]

Cheers Chris. I'll look up that thread.

[pathbrae]

A lot of the power-banks (the car-starter types) come with a power to 12v car socket so that should work with the car charger. I've never tried it though so can't comment on how many charges you might get.

[on the rocks]

I bought one of these to charge my radio when on camping trips
http://www.energizerpowerpacks.com/prod ... P0064&l=en

The USB-C socket can provide 12V. I bought a USB C to jack lead which I use to charge my Horizon HX 400 radio in it's cradle. The only problem (more a slight annoyance) is that I have to have something plugged into one of the standard USB sockets at the same time in order to "wake up" the USB-C supply to the radio

I can also charge the powerbank from a cigarette lighter socket

[mcgruff]

Omnicharge make some small powerbanks with 12V DC and even 240AC outputs. Not cheap though.

[Nismosteve]

Thankyou for all the input guys I will look into the recommendations.

[Chris Bolton]

The USB-C socket can provide 12V

I always find useful and interesting things on UKRGB!

Having read that, I have just gone away and educated myself a bit on USB-C, and not only can it provide different voltages if required by the device, the cables are not generally interchangeable. I know devices with mini-USB and micro-USB tend to have instructions that say you should use the cable that came with the device, but I've usually ignored that and regarded cables as interchangeable if they have the same plug. Not true for USB-C, you can damage the host or the device - and the cables I have aren't labelled, either!

[guyak]

Another approach for long trips is to power the radio externally,
which avoids the inefficiencies (and hassle) of battery-to-battery recharging in your tent.

I did this (some years ago) with an HX851e DSC radio by modifying an FBA-38 AA battery adapter
so that a spiral cable entered it through a cable gland and was soldered onto the adapter's AA contacts.
The other end of the cable went through a side-entry cable gland into a doubled-up dry bag
containing a big lipo battery. The radio was clipped onto the BA with the battery in one of the BA pockets.

This setup was watertight and surprisingly reliable going round the UK
- I only needed to change the battery once every week or two.
(Although I kept a spare HX851e in the day hatch just in case).

[Nismosteve]

Thanks for that guyak and chris b. I am an Aeromodellor and have some large Lipo's. Never even thought of using them for that. Brilliant idea.

[andynormancx]

Many VHF radios are limited to lower power transmission when running from the AA adapter. Not sure if that applies to the HX851e.

Possibly not an issue, as from what I can tell, most of the time line of site for a kayaker is a lot more relevant than whether you're transmitting at 5 watts vs 1 watt. But something to be aware of.

[Northern Blue]

Trying to respond to this thread, but I’ve been blacklisted via my usual device.... I’ve never been blacklisted for anything before ?

[Chris Bolton]

I'm guessing it's a phone or a 3/4g modem you've been blacklisted on? The problem is that there are many more devices than IP public addresses, and until IP v6 takes over from v4 that will remain the case. So many of the mobile operators use a system called CG (Carrier Grade) NAT - that means they group together about 250 SIMs and give them one public IP address, with each one getting a private IP. Very much like the way NAT works on your home network, one public IP and each device gets a private IP. So if any one of the 250 users has done something to get blacklisted, that single public IP and all 250 users are blacklisted too. UKRGB uses published blacklists to stop spammers posting.

The simple fix is to turn your phone off for a minute and when it restarts it will have a different IP.

[seawolf856]

My lithium pump battery (Tracer 12v) has a handy plug in lead with a 12v socket on the end so my VHF car charger just plugs straight in. I can also use a standard ‘bullet’ type USB adaptor to charge any of my other devices which has a USB charging lead. Compatibility is the key and using a 12v power source makes everything so much easier.

[Northern Blue]

I'm guessing it's a phone or a 3/4g modem you've been blacklisted on? The problem is that there are many more devices than IP public addresses, and until IP v6 takes over from v4 that will remain the case. So many of the mobile operators use a system called CG (Carrier Grade) NAT - that means they group together about 250 SIMs and give them one public IP address, with each one getting a private IP. Very much like the way NAT works on your home network, one public IP and each device gets a private IP. So if any one of the 250 users has done something to get blacklisted, that single public IP and all 250 users are blacklisted too. UKRGB uses published blacklists to stop spammers posting.

The simple fix is to turn your phone off for a minute and when it restarts it will have a different IP.

Thanks Chris,

I am tethering my iPad to my iPhone’s 4G until my new broadband goes live tomorrow. Strangely though, using the phone directly got the previous message through and hopefully this one too.

I’ll try again tomorrow after installation.

[Northern Blue]

May help in the meantime....

[PlymouthDamo]

Trying to respond to this thread, but I’ve been blacklisted via my usual device.... I’ve never been blacklisted for anything before ?

I'm pretty much permanently blacklisted from this site as I've gone over to using my phone's mobile hotspot for all my internet use. There's an easy way round it: use a VPN. The 'Opera' internet browser (for Windows or Android, and probably on iOS and Safari too) incorporates a free VPN, so you just have to click on a button and your IP address is changed.

[mcgruff]

It should also be possible to DIY a 12V power supply with a bunch of 18650 batteries connected to a ready-made step up converter like this.

That's more or less what you'll find inside a standard powerbank: a bunch of 18650's and a circuit board.

[andynormancx]

It isn't clear* that that buck converter has any battery protection in it. A standard powerbank doesn't just have a buck converter in it, it also has battery protection circuitry in it to turn off the output when the charge in the batteries gets too low.

Without this protection circuitry you will damage your cells if you let them discharge too much.

* it is possible that setting the input voltage on that converter sets acts as battery protection, if so, make absolutely sure that it is set to a sensible voltage for the cells connected to it...

[Nismosteve]

Cheers Northern Blue. That is very interesting.

[Chris Bolton]

I would be cautious about a DiY power supply with multiple batteries. Apart from protection against excessive discharge (mentioned above) the batteries would need individual charging circuits that detect when charging is complete, as they wouldn't all reach full charge at exactly the same time and overcharging can cause them to explode.

[andynormancx]

I know it is the done thing in model aircraft, but you’ll find USB battery packs don’t generally charge the cells separately.

[andynormancx]

I’ve also run into the mobile deny listing today, for the first time. I’ve been using mobile internet for our home internet for over a year. First time I’ve seen the deny list kick in, I guess there must have been some updates to the list on UK mobile IPs recently.

[mcgruff]

It isn't clear* that that buck converter has any battery protection in it.

AFAIK some batteries have protection built-in but no doubt it wouldn't do any harm to have a second layer of protection. Protection circuits can be picked up pretty cheaply too.

One of the challenges would be making a robust & waterproof unit. Smothering the circuits in epoxy should help with that.

[mcgruff]

Apart from protection against excessive discharge (mentioned above) the batteries would need individual charging circuits that detect when charging is complete, as they wouldn't all reach full charge at exactly the same time and overcharging can cause them to explode.

Good point. If I was experimenting with this, I'd use removable batteries for a variety of reasons. Then you can charge them up with a standard charger.

It also means you can rob your VHF battery pack if lighting is a higher priority (assuming you have a 18650 head torch, of course).

[andynormancx]

18650 cells rarely have protection circuitry

[mcgruff]

They shouldn't be hard to find. I've got a high-quality, high-current battery in my headtorch with built-in overcharge/discharge protection. I've also got some unprotected cells which I use as a portable powerbank (with a Nitecore F1).

Protected are probably the best choice for demanding applications. For example, if water gets into a battery holder external protection circuitry won't stop it shorting out but internal protection might (unless the water gets right inside the battery casing).

I'd think the 18650 cells used in most powerbanks probably aren't protected so in this respect at least you might be able to build something better.

[mcgruff]

EDIT: "I'd think the 18650 cells used in most powerbanks probably aren't protected"

--> I mean they probably don't use batteries with extra internal protection. The powerbank circuitry itself will almost certainly have charge protection.

[andynormancx]

I wasn't saying that they were hard to find, they aren't, RS Components carry them for example.

https://uk.rs-online.com/web/p/speciali ... s/8801558/

(they are twice around the price of quality unprotected cells of the same capacity, though still not expensive in the grand scheme of things)

However unless someone has deliberately gone out to buy 18650s with built in protection then they are very unlikely to have ended up with some, as the vast, vast majority of them are just bare cells.