# 1.2 Miles !?



## Coley (Jul 26, 2007)

Sad to say, it is true.

AND the battery that runs the vehicle lights, radio, fan, etc. cannot be jumped by the propulsion battery pack!!!!!!!

I jump started one at an energy fair last year, because he ran the vehicle battery down listening to the radio!!!!!!!

What engineer didn't think that might just happen??

Some pathetic planning..........


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## poprock (Apr 29, 2010)

my 36v hillman will go 3.2ks or 2 miles @ 30kph with scrap traded batteries from Battery World in Cessnock. If they want my expertise they can contact me.


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## TX_Dj (Jul 25, 2008)

Yep, they're not really EV's, they're ICE vehicles with some electronic gimmickery. 

But... most of them (especially those with an "EV Mode") can benefit from plug-in conversion.


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## mmw109 (May 28, 2010)

I just find it amazing that Toyota don't sell this plug-in conversion as an upgrade. Considering that they've made a whole button for 'EV' mode. 

(interestingly the Auris is actually more economical than the prius - I think that might be down to less gadgets).

That thing about not linking the traction pack to the 12V pack is pretty surprising as well. 

They really should post on here before they start shouldn't they ?

"I'm thinking of designing a new Toyota Hybrid, should I have a DC/DC converter to connect my ... "


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## CroDriver (Jan 8, 2009)

TX_Dj said:


> Yep, they're not really EV's, they're ICE vehicles with some electronic gimmickery.


Just enough electronics to stick a big HYBRID sticker to back of the car so that the Hollywood stars feel good when driving it...


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## TX_Dj (Jul 25, 2008)

CroDriver said:


> Just enough electronics to stick a big HYBRID sticker to back of the car so that the Hollywood stars feel good when driving it...


Ain't that the truth. Well, at least those "in the know" are doing it right, like George Clooney and his Tango, and others who are driving Tesla roadsters. I'm sure we'll start seeing some of them driving Nissan Leafs soon enough, and even more getting the Volt (sigh).


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## Tm PV1 (Jun 5, 2010)

Maybe stick one of those HYBRID stickers on the back of the Volt, too. What label would you put on the Volt, E-REV or serial hybrid? I'm still wondering how the Volt and the EV1 can have the same battery rack, the Volt having better batteries, but the EV1 has the Volt on electric range. Maybe GM sabotaging the Volt too?


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## roflwaffle (Sep 9, 2008)

mmw109 said:


> Not just 1 mile a whole 1.2 miles !
> 
> I just got the brochures through for Auris and Prius hybrids yesterday.
> 
> ...


It's because Toyota only uses a fraction (~.4kWh give or take) of the 1.3kWh pack due to wear/balancing constraints. If the pack is already on the low side, 1.2 miles may be all that someone can get.



> You can probably see that if you restrict the operation to between the 40% and 80% limits that Toyota sets, then you avoid the sudden changes at both ends. (And so increase reliability dramatically)  So why the angst about doing this even once?
> At the lower extreme there 2 good reasons not to go down to 0% (which you CAN do, bypassing the protection, if you run out of gas and insist in driving on the battery trying to reach a gas station.) The first is, once it has gone down that far, there is (for most people) no way to re-charge it without getting Toyota's rare and expensive charger involved at a dealership. Strangely, the first Japanese Prius had an inverter built in that would allow you to charge the HV battery from a 12v source. So does the current Ford Escape hybrid. So if you do this, you are looking at losing the car for a while and a large bill. The second reason, which could be more expensive, is that you can only discharge such a battery down to nothing at high currents if all the cells are identical. If one cell has slightly less capacity then the others then it will be discharged fully before the others are. At which point the current that continues to flow from the others starts charging this one up backwards. This battery chemistry does not take kindly to being charged backwards. Permanent  damage is likely to occur. So avoid doing it at all costs. Going down to 10% and watching for imbalance is probably safe but this might not leave enough to re-start the car. Toyota sets a lower limit of ~40%.
> At the upper extreme, there is a good reason not to go to 100%. For most of the charging cycle, this prismatic pack is about 85% efficient in storing electricty, with the remainder dissipated as heat. But as you get closer to 100%, more and more of the electricity coming in gets converted to heat and the cell temperatures start to rise rapidly. If continued, the electrolyte could boil away, (read pack damage). Now modern 'smart' NiMH chargers try to prevent this by watching for this rise in temperature and turning the charging off. This helps but is not perfect. So Toyota chooses instead to set a maximum charged level of 80%, cutting back the charging current from either the ICE or from regeneration as you get closer, until it accepts nothing and the ICE has to revert to compression braking.
> What this all means is that the theoretical capacity of the Prius pack which was ~5AH at any reasonable EV current if it went from 100% down to 0%, has now been reduced to what you get going from 80% down to 40% or 2AH or about 400wh. Thats enough to do maybe 2miles and is only true if you start at 80% after coming down a long hill. With it normally sitting at 60% you're down to 1/2 of that, or 1 mile, on a flat road. Maybe 1 1/2 miles if you are real lucky and very light-footed. (As the watt-hours required per mile drop if you go slow)




The only cost effective way to get more range is to install a BMS+ and a few more packs. Not only does that give you more capacity, so range would be ~5 miles all things being equal, but you can also set it so that it takes more energy from the pack after you completely charge them, so 10+ miles is possible, albeit expensive at ~$2500 plus install if you can't DIY.


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## roflwaffle (Sep 9, 2008)

Tm PV1 said:


> Maybe stick one of those HYBRID stickers on the back of the Volt, too. What label would you put on the Volt, E-REV or serial hybrid? I'm still wondering how the Volt and the EV1 can have the same battery rack, the Volt having better batteries, but the EV1 has the Volt on electric range. Maybe GM sabotaging the Volt too?


Since the Volt is a plug-in, the battery pack has to be warrantied by law to last ~100k-150k miles depending on region, so GM only uses ~8-10+Kwh w/ the Volt. The EV1 could use all ~16-18+kWh, so right there it has twice as much energy. On top of that it was slightly smaller and way more aerodynamic than the Volt.


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