prius dual auxillary battery

[lurgetaxa]

I was wondering if anyone has put another battery on a prius auxillary unit. I hvae the original gel prius battery, but I would also like to add an deep cycle battery in a series mode with the original unit, so the
hybrid battery wont have to charge it to much. I was also thinking about adding two electric regenerative
motors somehow on both the rear wheels and having it charge the auxillary batteries as the car drives.

If anyone has put an extra battery unit on there prius please comment back on how the prius works with it.

[tochatihu]

I hope that you are kidding about connecting it in series, and realize that parallel would be correct.

Just in case of a weak 12 volt in a remote place, I have a 7 amp hour "helper battery" which is always trickle charged when the Prius in in ready mode, but can only be used for booting up when an added dash button is pressed. The circuit is quite simple.

No comment on adding regen motors to the rear wheels.

[David Beale]

If you're serious about this, use a "battery isolator". It will ensure you do not overcharge one battery while undercharging the other.

You will also want to use another sealed battery, either another gel cell type or a glass mat type, such as an Optima. They are available in smaller sizes - a #51 is the smallest I've seen in the Optima line.

Both types will not spill electrolyte if broken in an accident. An important consideration.

Not sure exactly why you're doing this, but if it's just to increase the battery capacity, just replacing the stock 12V with a larger battery is the best way to go. I'd go this way with an Optima #51 - but you -WILL- want to manufacture a proper hold-down/battery tray for it and ensure the battery compartment is properly vented. Even sealed batteries can vent from time to time.

[lurgetaxa]

I want to have a charged battery most of the time so the hybrid system wouldnt have to charge the auxillary battery most of the time, and finding a way to fit a electric regenerator on the rear wheels and figuring out how to keep the two batteries charged correctly would help me with some interior hardware I'm
thinking of adding.

[seasalsa]

<div class='quotetop'>QUOTE(lurgetaxa @ Aug 13 2006, 10:51 AM) [snapback]302594[/snapback]</div>

I want to have a charged battery most of the time so the hybrid system wouldnt have to charge the auxillary battery most of the time, and finding a way to fit a electric regenerator on the rear wheels and figuring out how to keep the two batteries charged correctly would help me with some interior hardware I'm
thinking of adding.
[/b]

Sorry, but it is not clear just which battery you are talking about. There is a Traction Battery and an auxillary battery.

[ekpolk]

More fundamentally, don't forget the science involved. There is simply no "free lunch." Assuming you could rig something to the rear wheels to feed charge to the aux battery, the car would have to overcome the added load imposed at the rear wheels to generate that energy. A Prius can add energy only two ways that I can think of: out of the gas tank (some of which gets recovered and "reused" via the traction battery) and from a tailwind (I suppose a tow truck might also suffice, but that would be cheating... ). Even rolling down hill, all you're doing is recovering some of the energy the car took out of the gas tank to get you up the hill in the first place. Yeah, a system such as you mention might result in minor deviations in the flow of energy within the total car, but it would be a wash overall, with the penalty of added weight and complexity. An interesting idea, but IMO, one that needs to remain merely an idea.

[David Beale]

Well, the simplist way to charge an extra battery that you don't want to connect to the system is to add a solar panel and charge from it. If you use a "cargo screen" (horizontal window blind over the hatch area) you can put a small solar panel on top of it, or you can place one on the dash. You would need to securly fasten it to prevent it from decapitating you in the event of an accident though.

You can then connect the battery to the system through a diode so power will only go to the car, not from it to the extra battery.

Note that if the stock 12V battery is fully charged, very little power goes to it from the Hybrid system, just what is being consumed by the vehicle electronics and a tiny bit of "waste".

Just from reading your messages, I think you may need to read some books on how electricity and electronics works. Otherwise you will cause expensive damage to this complex electronic car!

[RexChu]

How about a simple approach.

For the 2006-2007 Prius:

Obtain an identical stock traction battery and integrate with the existing traction battery.

Would this increase capacity as there is now more storage? Theoritically, if wired properly, the computer would notice a small difference in a slower decrease in energy coming from the battery(ies) and slower charge time. I wonder if this would trip an error code?

I surmize that we could place the second traction battery in the black tray under the cargo floor. There will be a cooling issue that would need to be addressed.

If this theory works, there could be secondary "kits" offered commercially (perhaps under the 8-10K price). Of course, only geared for professional installation (like the Prius Plus products).

Benefits would be better capacity and better range in EV mode. This should result in better MPG.

Just an idea...

[qbee42]

<div class='quotetop'>QUOTE(lurgetaxa @ Aug 13 2006, 01:51 PM) [snapback]302594[/snapback]</div>

I want to have a charged battery most of the time so the hybrid system wouldnt have to charge the auxillary battery most of the time, and finding a way to fit a electric regenerator on the rear wheels and figuring out how to keep the two batteries charged correctly would help me with some interior hardware I'm
thinking of adding.
[/b]

Not to put too sharp a point on it, but this idea is just plain silly. Your "regenerator" is not going to be more efficient than the one built into the Prius, so you will add weight, cost, and complexity for no gain.

Tom

[NoMoShocks]

<div class='quotetop'>QUOTE(rex-n-efx @ Jun 28 2007, 11:24 AM) [snapback]469537[/snapback]</div>

How about a simple approach.

For the 2006-2007 Prius:

Obtain an identical stock traction battery and integrate with the existing traction battery.

Would this increase capacity as there is now more storage? Theoritically, if wired properly, the computer would notice a small difference in a slower decrease in energy coming from the battery(ies) and slower charge time. I wonder if this would trip an error code?

I surmize that we could place the second traction battery in the black tray under the cargo floor. There will be a cooling issue that would need to be addressed.

If this theory works, there could be secondary "kits" offered commercially (perhaps under the 8-10K price). Of course, only geared for professional installation (like the Prius Plus products).

Benefits would be better capacity and better range in EV mode. This should result in better MPG.

Just an idea...
[/b]

I REALLY like this idea. Let also add a battery charger and a cord you can run into you house at night to connect to the electrical grid. We could call it a PHEV. We can start a websight to help other people who want to make PHEV. We could call it calcars.org or similar.

Maybe some small start up companies will make kits to drop in to the spare tire well to make this a quick conversion for about $10,000. They will most likely only sell to fleet users at first. Maybe we could get the US government to offer a $3,500 tax rebate for poople to make this conversion, and just maybe, the added demand might entice more companies to come out with lower cost drop in conversions around $5000-6000 price point.

We will have to wait and see. Some new killer battery technology leep forward could really serve as a catalyst too.