Gen 2 Prius 12V Battery - Yuasa (Original Supplied) Vs. Bosch S4

[sushd]

Two years hence:

I had installed the Battery in May 2015, and the economy improved significately during the summer months touching 60-62 mpg (actual) gradually reducing to mid-high-50s as it became cooler. The lowest I got was 48 mpg during the following winter. By the time the Battery was 1 year old (and since then), the highest I have achieved is 55-56 mpg and the lowest about 46-47 mpg ..... which is similar (or marginally better maybe) to what I was achieving with the original Battery that I had binned.

The (big) improvement in economy lasted only a year, sadly!! 

Do take into account that our Prius doesn't get around much ... about 500 miles a month, with a daily short commute 5 miles from home to train station and vice-versa on weekdays.

BW.

[demag]

I noticed recently my engine running more and more even in the warm weather. When starting in the morning the engine would fire up within 30 seconds. I did a Battery check in the secret menu on the mfd and it was showing just over 12v but under 12v on load. Today waiting at a red light it cut out! As the engine usually stops when stationary I never even noticed until the lights changed and I started rolling backwards! Of course all the repmobiles had their hands straight on the horn, the lights had been on green 5 seconds and nothing had moved. I looked at the dash and there was just blackness, I hit the brake and pressed the button and luckily it fired up.

I'm hoping it cut out because of low voltage so I went to our local spares shop and he had a ring round. These things are like rocking horse poo with hardly anyone stocking them, eventually he located one and it should be here tomorrow. £190 genuine Yuasa ouch! I'd seen equivalents on eBay for 35-40 quid and wondered why the wild price range however reading this article now I know. Will update.

[Catlover]

You can get 12v batteries of the 35a size and, importantly, the same physical size as the original Yuasa Battery. The difference is the low priced batteries are "wet" batteries ie acid batteries. The Battery being positioned where they it is in the boot on the drivers side, all you need is a bad smash into the car at that point and Battery acid could be flying through the cabin and occupants getting splashed - not recommended!   There may well be technical reasons as well why a "wet" battery is not suitable for the hybrid Auris/Prius (yes its the same Yuasa battery in the Auris).  Few weeks ago our Auris (wifes car) was battery drained after 2 days lack of use. I looked all over internet/ebay and was half tempted by the lower priced batteries, but in the end went for the recommended AGM battery. AGM stands for Absorbent Glass Mat, see this link https://en.wikipedia.org/wiki/VRLA_battery , very interesting.  They are safer then "wet" batteries, can be positioned in whatever direction, and the plates can be flat or circular. I chose to but an Optima AGM battery, which I got from Tayna in Abergele, and the cells are circular - I posted a photo of this only a few weeks ago in the Auris section on this forum - check it out. It cost me £130 and as I live less then 40 miles from Abergele, North Wales, I went and collected. They do next day delivery for about £8. Order before mid afternoon (cant remember the cut off) and you will have it next day already charged up and ready to fit. And when I say ready to fit, that is what I mean. The original battery has a vent pipe for the fumes. This is important as the battery sits within the passenger compartment and a build of of fumes would be very bad (could cause explosion). I have heard of people fitting some AGM batteries and having to adapt the vent tube form Yasa to the "new" battery. Not with the Optima, the original vent tube just pushes in the fixture as did the Yuasa.   

So I paid £130 for a Optima AGM battery, and I understand Toyota will do the Yuasa for the same price or not much more, so dont spend your £190 yet !!!!!

 

[FROSTYBALLS]

The Toyota Battery is £120 - https://www.toyota.co.uk/owners/service-mot-maintenance/repairs.json

[Gerg]

Just an idle thought here.

If I remember correctly, the Battery for a Yaris hybrid is the same part no. as an Auris hybrid and also a Prius Gen 3.  (Don't know about a Gen 2).

The Toyota ''menu' price for a lead/acid Battery is the same for all types of Yaris, and the and same for all types of Auris (but the Auris is £10 (IIRC) more than a Yaris).

As the Yaris menu price for a Battery is a little cheaper than the others.  What would happen if you asked Toyota for a battery for a Yaris and then fitted it to your Auris/Prius yourself?

[Heidfirst]

28 minutes ago, FROSTYBALLS said:

The Toyota battery is £120 - https://www.toyota.co.uk/owners/service-mot-maintenance/repairs.json

& that includes fitting ...

[Catlover]

Is the £120 inc VAT ???   The £130 Optima inc VAT, I fitted, straightforward.

[FROSTYBALLS]

6 minutes ago, Catlover said:

Is the £120 inc VAT ???   The £130 Optima inc VAT, I fitted, straightforward.

Yes

[Catlover]

That makes a Yuasa as supplied by Mr T is good value. 

[kithmo]

Not as straight forward on the gen 2, extra black box full of capacitors to remove IIRC, quite fiddly.

[larry609]

I ran my 12V dead by leaving a car door open for 4 days.

THIS reconditioned my Battery - but we'll see how well the Battery does over the next 3 or 4 months.

I ran a previous Battery dead by leaving a BT transmitter plugged into the diagnostics port for a week - and that battery never really recovered. THEN, I got this after have gotten a new battery from the dealer.

 

https://www.amazon.com/gp/product/B006G14FK8/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

[kithmo]

I have the 3.8 amp Ctek charger/conditioner and due to my low annual mileage I pop the charger on every 4 weeks in the winter and 6-8 weeks in the summer to keep the Battery conditioned. I chose the 3.8 amp version when I had the Gen 3 as the manual said max charge rate 4 amps (AGM battery), I don't think it matters with the gen 4 as it's a standard lead acid Battery.