12 Volt Lithium Battery...Possible ?

I'd never heard of these guys but http://www.shoraipower.com/t-faq.aspx says

There was some discussion of li-ion 12 volt batteries at http://www.mynissanleaf.com/viewtopic.php?p=114815 and a pointer to http://www.porsche.com/usa/aboutporsche/pressreleases/pag/?pool=international-de&id=2009-11-23-02. 1904 Euros = $2545 USD

 

Your 12V battery is fairly large for a motorcycle battery, 38 A-Hr. It does look like one though, complete with a vent tube. But for a different reason. It's in the cabin so must vent outside (ALL batteries may vent, even "sealed" ones).

Do some research, and you'll find you -can- buy lithium rechargeable cells. The ones large enough for direct replacement cost in the area of $100-$200 per cell. You would need four cells. You would also need a charging circuit as lithium cells are charged differently than lead acid cells.

Not very practical at this time.

 

DO NOT change out your 12V battery for a Lithium-based battery!!!

The 12V battery is a standard Lead-acid automotive type battery. The nice thing about these batteries is that they are very robust and can be deeply discharged and are forgiving of over-charging.

On the other hand, Lithium-based batteries are relatively more finicky about their charge and discharge levels. If one should over- or under-charge a Lithium battery by just a couple of volts, it will undergo a chemical change that will ruin the battery. These batteries require special controllers to prevent this problem. Also, if they overheat, they can explode.

ONE CANNOT SIMPLY DROP A LITHIUM-BASED BATTERY INTO A SYSTEM DESIGNED FOR A LEAD-ACID BATTERY!

So, get your head out of the clouds.
If you really want to make such a change, consult a qualified battery engineer first.
Note I said a battery engineer, not an automotive technician.

'Nuff said.

 

I have to ask, what problem you you trying to solve?

Until we know that, we can't be helpful, only discouraging. Lead Acid is such a known, refined technology, that it will be 'better' than better technologies until they get as experienced.

 

Actually the 14 volt "constant voltage' charging in our Prii is just above the "Float" voltage for SAFE LiFePo batteries (3.4 volts per cell times 4 cells) so a 4 cell battery would get charged safely but slowly. The price is steep for 4 cells (about $1500 for 80-100 amp hours for 4 cells, why do it to just match capacity with the OE battery?) and unless you regularly take long drives, you will need an external balancing charger and a Battery Management System (BMS) to help maintain cell balance over time to preserve your investment.

The Valence U1-12XP is a fully implemented 40 am-hour,12v, replacement Lithium Iron Phosphate battery with built-in BMS, but it also costs about $1500.
http://www.valence.com/energy-storage/lithium-phosphate-battery-data-sheets
They are slightly smaller than an Optima, weigh half as much, and have slightly higher capacity. The built-in BMS prevents discharging below 10v so they would survive in a Prius.

JeffD

 

I think all he wanted to do was to stop you from setting your car on fire. Even if you weren't trying to put a Li-ion battery in your car, someone else reading the thread might get the idea. And better to be safe than sorry when it comes to such things.

 

We all have the right to ask any question!. I wish I could get my head in the clouds...............:rockon:

 

Uh oh...

I thought the question was valid. And the some of the answers a little combative.

But to the OP? You might not want to come back with calling us freeking geeks and pocket protector boys....

Prius Chat is a diverse community.

Now if you'll excuse me, my ball point pen just broke in my shirt pocket.....

 

Actually I have replaced most of my UPS batteries with LiFePO4 batteries. Have not had any issues with them yet. Only down side is that they dont get fully charged so you dont get full capacity but on the other side that will make them last longer.

This would most likely be the best option for a replacement 12v battery for the Prius. Its about $500.
LiFePO4 Prismatic Battery: 12.8V 40Ah (512Wh, 100A) with Balancing PCM (48.0)

I dont like the whole BMS idea but since its being charged with lower voltages the BMS should be relatively safe. If you plan on getting the above battery and use it in an automotive environment you will want to take it apart and use Nord-Lock washers for the connections.

 

And so far as I know we have the right to give honest answers.

 

That's what you got, the facts.
You just did not want to hear them.:bored:

 

From a innocent question you sort of got caught in the midddle. Everybody has a right to ask any question on this forum AND everybody has the right to a honest and sincere answer. It is very easy to interpret just one word in the wrong way. Agreed?

 

NO, Not at all!

 

Very interesting read so we are getting to a better, stronger and lighter starter battery (finally). So the OP had a very valid point. :rockon: