Red Triangle, drives well, but battery at 9.6V - am I on the right track?

Yes you definitely need a new 12v. Just swap out the old with new. Hopefully that'll resolve your red triangle.

 

check with brit prius, he's got the rundown on uk 12volts.

 

At 9.6 volts I am surprised your running at all. Low voltage 12 volt batteries in the Prius can give all sorts of problems.
After fitting the new battery you will loose the drivers window auto close setup, and the car will take a little while to relearn you driving so will use more fuel.
Also after fitting you will need to go through two start procedures before it will start.

John (Britprius)

 

If you take my advice do not buy from Halfrauds. There are many batteries in the UK for the Prius. Varta and Bosch make replacements starting at around £40 depending on the length of guarantee (up to 5 Years) The battery has to be a very specific size to fit and should have JIS posts (Japanese Industrial Standard) these are smaller than normal imperial posts. The positive post must be on the left with the terminals (posts) closest to you.
Buy the battery from any motorist spares shop If you need battery model numbers let me know.
Expect to pay about £100 for the battery at the dealers plus fitting.

John (Britprius)

 

I would ring the dealer and check the price first you could easily save £50.

John (Britprius)

 

[/QUOTE]I would ring the dealer and check the price first you could easily save £50.

John (Britprius)[/QUOTE]


John are you still recommending the Mobility Batteries or have the price options increased significantly in the UK?

 

I would ring the dealer and check the price first you could easily save £50.

John (Britprius)[/QUOTE]


John are you still recommending the Mobility Batteries or have the price options increased significantly in the UK?[/QUOTE]
I would still recommend the mobility batteries over OEM type batteries. Both have risen in price due to the increase in the price of lead, but not substantially. Most people however understandably do not want to alter fuss with the terminals. I have now changed a number for friends.

John (Britprius)

 

I thought the Toyota price was fixed at £95 including fitting. Considering the faff with the vent tube it might be worth just getting the dealer to fit it?

Repairs & Parts - Toyota Owners | Toyota UK

Scroll down to the Fixed Price Repair section and then update the car to the correct Prius and it displays the 12v cost.

Maybe the op would consider the Hybrid Health Check for £39 as his car is close to warranty expiry or maybe out of it?

 

Fingers crossed we don't get a cold snap.

Have you considered the Hybrid Health Check? It's only £39 and offers an additional 10k miles/12 months warranty on your HV battery. Might be a consideration as you're now out of manufacturers warranty.

 

And it's unlimited mileage, assuming your HV battery passes the first time. I haven't heard of one on the UK forms that hasn't.

So whilst you only have 2 years left (it's 10 years inclusive or upto 11), the benefit depends on how many miles you do a year. They also provide the HHC free as part of a main dealer service so it could work out cheaper to go to the dealers overall. And you could always try and get the dealers to price match - though not all will. You don't ask, you don't get

 

Be VERY careful when jump starting a Prius. Your sister must NOT rev her engine and you must ensure you don't short out the jump leads on the car as you'll fry the computers. Also, the Prius takes an age to charge a dud battery so once you are started you don't want to stop.

Good luck

 

It is actually best if the "donor" vehicle is left OFF......and the connection is removed immediately after the crippled car starts.

 

The Toytota extended guarantee is free with any service so if you wait till then it would cost nothing.

John (Britprius)

 

I read that 4 times and then stared at it for a while and then read it again.
I still don't understand what you are trying to say.