Prius Battery Pack as a power source and storage for HAM Shack

Hi HOPMAH,

Go talk with Bob Bruninga, WB4APR (yea, the guy who invetned APRS). He can fill you in on all sorts of that stuff.

30 amps is not too much for the 12 V power converter (presumably you mean 30 amps at 12V). But many people tap across the traction battery, with a much bigger UPS inverter. Then run the shack off 110 Volts. Its been done, people just leave the car in ready, and when the traction battery gets low, the engine comes on and recharges it, all automatically. Many people have use the Prius this way to run the furnace during an extended power outage due to ice storms.

Oops, reread your post. Well, you will need a BMS (battery management system) to be sure the battery gets recharged and discharged evenly. Otherwise you will kill a cell, and as they are all in series, that will require rebuilding the pack. Bob is another guy you can talk to about screwing up Prius packs too, hi.

On third thought, why not buy a 2004 or 5 Prius with body damage, drive or trailer it up to your shack location. Park it , and put it on blocks. Then proceed with what I was talking about in paragraph two. You could probably get one cheap somewhere.

 

There must be any number of sites and books describing this in complete detail using one or a few 12V lead-acid batteries. Using a Prius high-voltage battery instead would be very much the hard way.

 

Welcome aboard!

Careful, or you'll find yourself on a Toyota lot kicking tires...

I think a lead-acid battery bank would be more cost-effective for your shack (we use them in telecommunications.) Granted, I'm not a power tech, but even if you have a Prius battery pack lying around, you'll be better off selling it on eBay and getting other batteries.

Good Luck!

 

Well it depends:

• 14,400 watts = 4 (radios) x 30 (amps) x 120 (V)
• 3,600 watts = 1 (radio) x 30 (amps) x 120 (V)
• 1,440 watts = 4 (radios) x 30 (amps) x 12 (V)
• 360 watts = 1 (radio) x 30 (amps) x 12 (V)
• ?? watts = 2 (computers), ? (lights) and ?? (rotator)

Could you clarify a few things:

1. Do you transmit all four radios at the same time?
2. Your receivers draw 30 amps?
3. Is this a 12 V or 120 VAC setup?
4. Do you have a 'Kill-a-watt' load monitor for the 120 VAC loads?
5. Do these loads require a sine wave source or can modified sine wave work?
6. How long is the expected disaster?

This is what I use for emergency house power:
Prius - UPS Project

Bob Wilson

 

The Prius battery is a 200V unit, consisting of 168 NiMH 6.5 A-Hr cells in series. Not my first choice for a backup system for 12V radios.

As stated above, you'd be better off with stationary lead-acid, AGM, or lead-calcium cells, a 12V solar system, and charge controller.

Bob, the HF tranceivers run 30 Amp on Tx (they put out 100W typically or 200W PEP). On Rx they typically draw less than 5 Amps. All the ones I'm aware of run 12V DC. Some do have built in 115V AC power supplies, but most use external supplies. The VHF and UHF tranceivers typically Rx at 1 Amp and draw 7 Amps for Tx with 30-50 Watts output.

 

Thanks David,

I was hoping the OP would post a more descriptive load description. In particular, I was wondering if some of his units were repeaters or if he was planning to operate a gang of four radio transmitters at one time (improbable and I thought against FCC rules.) I was also hoping for a better description of his 12 V vs 120 VAC loads.

The simple answer is the Prius can easily provide 1 kW of 12 V power until the tank run dry. Depending upon inverter efficiency, easily 900+ W. If one buffers with a deep discharge battery, higher peak power could be provided but there would need to be a current limiter, 75-80 A at 13 V.

Others have gotten 3 kW of 120 VAC by tapping the traction battery. However, they tend to use some fairly large, UPS inverter boxes.

Bob Wilson