Powering FT897 in the field

[KD8LWX]

I like the FT897, but don't like options for powering it in the field.

The internal batteries are expensive and don't last very long and recharging them requires taking the unit apart and couldn't be done in the field very easily. And to top it off, it is limited to 20W output. Although I have been told that 20W is good enough, I don't like being limited.

I am looking for alternatives. I am not an electronics guru.

I have come up with a couple ideas that I will run past the group.
Could I/should I, try to wire 4 RCR123A together get my power? Maybe multiple packs to get more mah?
4 Pack RCR123A 3V 900mAh Rechargeable Li-Ion Battery with Smart Charger
I like the idea. I use 123 batteries in other devices so...., but I am not sure I have the skills to pull it off.


OR
Wagan Tech Self Charge Auto Jumper 2045
Wagan Tech Self Charge Auto Jumper 2045
Wagan AC to DC 12V Cell Phone/PDA Traveler's Adapter - USB 2435
Wagan AC to DC 12V Cell Phone/PDA Traveler's Adapter - USB 2435
It would be nice if I had one of these on hand in case I need a power jump.

 

[SR385]

Get a deep cycle marine battery 80+ Ah or so, AGM or gel type. A marine battery box with a nice carry handle on it and a trickle charger made for AGM or gel batteries.

It will last a lot longer and will take the full discharge cycles. If you really want to squeeze it, get one of the 'battery booster' voltage regulators. Will keep the output at 13.8 until there's nothing left of the battery. Otherwise you'll need to keep it down around 50W or so so the radio isn't having a hard time drawing the current/voltage it needs.

I've had bad results with the battery jumper/boost setups. They work o.k. for VHF/UHF radios with lower draw, but they really don't hold up well that I've seen.

Also generally speaking, the difference between 25W and 100W is pretty small effectively and the battery will last quite a lot longer at 25W. If propagation is good enough for 100W, generally speaking 25W will do the job too. For portable you want a processed and punchy audio anyway for SSB contacts so that will help alot. This way you have the reserve for 100W if you need it but can run at 25W otherwise.

 

[Moleculo]

If you use the internal batteries, there's not anything you can do about the 20 watt max output. However, there are some aftermarket batteries available for less and also a rapid charger available. Check One Plug Power OPP-897 for more info.

I also use a marine/rv deep cycle battery to do what you're describing. You can operate for quite a long time and the batteries also charge pretty quickly. It's a better solution than the built in battery packs, IMO.

 

[Captain Kilowatt]

You won't want to use those 123 batteries if they are only rated at 900mA/hr. Most decent HT batteries are at least. Don't discount what 20watts will do;it's only about one S-unit down from 100 watts. The best bet is an external battery like a deep cycle type and some sort of charging method or a combination of methods such as solar as well as wind powered or even hooking up to the car battery/alternator system to recharge.As for being limited when using the internal batteries I am sure there is a way to defeat that but I am not sure if it is a good idea or not. I believe the power harness from the internal batteries has a brown (?) wire connected to the battery which is what tells the radio to limit power to 20 watts. Disconnect the brown (?) wire from the harness and that should defeat the power limiting.

 

[KD8LWX]

Get a deep cycle marine battery 80+ Ah or so, AGM or gel type. A marine battery box with a nice carry handle on it and a trickle charger made for AGM or gel batteries.

I was at Cabelas today looking at those. I like the idea. It I was planning on operating all day in field conditions and then take the setup home or to a generator (e.g. Field days or in the aftermath of Katrina) I think that would be the ticket. But right now I am thinking more man portable (lighter weight and size), less talk time. (I still might do the marine battery in the future.)

I've had bad results with the battery jumper/boost setups. They work o.k. for VHF/UHF radios with lower draw, but they really don't hold up well that I've seen.

Talk to me about why they don't work well.
This one is Ni-Cad, so it is not as good as say NiMH. I will have to make sure I charge it the day before I go out because I have been told that Ni-Cad will slowly loose power on the shelf. I will have to make sure I don't create a battery memory where it will not totally charge/discharge.
But overall I don't see a "draw" issue? What am I missing? What don't I understand?

 

[KD8LWX]

You won't want to use those 123 batteries if they are only rated at 900mA/hr.

I am not very good at this so check my logic.
I can run 4 batteries in serial to get my voltage, but I only get 900mAh. Lets call this one pack.
If I run say 4 pack in parallel, I will get my voltage and 2800mAh. This still isn't much, but I could rig up 8 or 12 or 24 packs.
Right?

 

[Captain Kilowatt]

I am not very good at this so check my logic.
I can run 4 batteries in serial to get my voltage, but I only get 900mAh. Lets call this one pack.
If I run say 4 pack in parallel, I will get my voltage and 2800mAh. This still isn't much, but I could rig up 8 or 12 or 24 packs.
Right?

Four packs in series gives you 12 volts and four packs in parallel gives you 3600mAh so therefore it takes 16 packs to give you 12 volts at 3.2 AMP/hrs.That's a lot of weight and money for such a small return. A sealed gel cell will give you 12 volts and 7 AMP/hrs or more for the same size and less cost and only be a bit heavier.About the only rig I would run on those 900mAh batteries is the FT-817 QRP rig. Face it, running battery powered portable is neither cheap nor easy unless you go with a single large size battery such as a marine deep cycle or a gel cell type. Something to be aware of as well is that some radios do NOT like to operate,in fact will NOT operate, when the voltage hits anything below 12.0 volts.

 

[SR385]

Talk to me about why they don't work well.
This one is Ni-Cad, so it is not as good as say NiMH.

Poor quality batteries...most of them are Chinese junk and that is why they seem so much cheaper than just a 'regular' deep cycle battery and charger.

The batteries have died on me on two different ones now, a no-name and a Black and Decker...garbage batteries. They just won't take and hold a charge shortly after buying them. The B&D, the charge circuit died I think, the other, the battery itself was bad.

Some friends have had o.k. luck with them, but a deep cycle full sized battery in a battery box will last much longer.

 

[SR385]

Poor quality batteries...most of them are Chinese junk and that is why they seem so much cheaper than just a 'regular' deep cycle battery and charger.

The batteries have died on me on two different ones now, a no-name and a Black and Decker...garbage batteries. They just won't take and hold a charge shortly after buying them. The B&D, the charge circuit died I think, the other, the battery itself was bad.

Some friends have had o.k. luck with them, but a deep cycle full sized battery in a battery box will last much longer.

This thread actually pushed me to finally get a battery backup for the shack wired up. Debating between a 100Ah and 200Ah AGM , but all the cabling is in place and the charger/isolator is in the mail.

 

[Luke_C]

These are an excellent solution.

http://http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200343105_200343105

This gives you an independant power source, requiring no outside source other than light. 110v or 12v power and good battery power. The soloar panel will charge larger batt's for you too, albeit a bit slowly.

A good friend of mine has one as part of his emergency gear, and I was real impressed with it. It's quiet, durable, and will give you plenty of power. No need for up keep on it, but you can charge it externally if you want. I like it, and when funds permit, I'll pick one up for back up power.

 

[Happy_Hamer]

I had the 897D, I like it BUT,,,,when you load that thing up with 2 batteries it gets heavy.

Taking that out for portable operation is not very easy because of its size and weight.

I sold mine and bought the 817ND instead, much lighter and easier to go portable.

I have made just as many contacts using the 817 at 5 watts as I did with the 897 at 20 watts.

If you already have the 897D, keep it and enjoy.

Buy the internal batteries for it and have fun. Just one thing you have to remember with 20 watts just like you do for 100 watts

ANTENNA ANTENNA ANTENNA