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UK 2004 Gen 2 - 12v battery replacement?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by afia2k8, May 20, 2020.

  1. afia2k8

    afia2k8 Junior Member

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    Hey guys,

    Not sure if my 12v battery needs replacing in my 2004 Prius. Any recommendations for cheaper alternative oem in the UK? Can't find the Optima yellow top here in the UK. Two years ago for my 2006 gen 2 prius I replaced the 12v battery at my local Toyota dealer for £120 fixed price (battery inc fitting) so that's the max I would go. I checked the boot and they've put in a new AGM tech S46B24R 12v 45ah 325a. But I'm planning to sell my 2004 Prius so don't really want to spend that much (I could probably only sell the car for about £1,100 due to the 147,000 mileage).

    1. I bought a 2004 gen 2 prius here in the UK few months ago from a friend to Flip - had a few things that needed fixing (side note - we don't have the SKS smart key system here). Due to covid, I currently drive the car in the weekends (10 mins each way to work and back per day). I've been doing this for 3 weeks and on the 4th week, had to get jump started. The car still unlocked and turned on but won't go into ready mode. After jump starting the car works completely fine again. I just drive it once mid-week now (about 20 mins) so that hopefully the 12v battery won't completely die now.

    I've looked in the boot, the current 12v battery is a Yuasa YBX3057 12v 45ah 400a (vent tube doesn't fit, had to buy a smaller vent adapter from bmw). I did the display check test:
    1st press - 11.7v
    2nd press - 11.4v
    Turn on - 14.3v

    2. Funnily enough, I decide to do a check on my 2006 prius gen 2 12v battery that was replaced by the Toyota Dealer two years ago and the voltage results came out worst!
    1st press - 11.3v
    2nd press - 11.1v
    Turn on - 14.3v

    So I went back to the dealer and they checked my 2006 prius. But they said the battery is completely fine. Perhaps most of the 12v display check test I've seen on here are using a bigger battery because you guys have the SKS smart system?

    Toyota dealer still offer 12v battery replacement fixed price for £125 inc fitting and vat - so I have that as an option.

    But I'm thinking, I can simply buy any 12v battery for replacement as long as I get a one that is a min 45ah 325a with the correct position/fitting for the vent tube? Or maybe i don't even have to replace my 12v battery because the voltage is much higher than my new battery I've just replaced 2 years ago?
     
  2. SFO

    SFO Senior Member

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    There is the possibility that you aren't driving these vehicles enough to keep the 12v properly charged, or they just need replacement.

    Do you know the age of either 12v battery?

    Do you have a low amperage charger that you could recharge the batteries with?

    If you don't have a charger handy, you can also leave either vehicle in 'ready' mode and it will charge the 12v for you. It may take 10+ hours.

    @Britprius has an excellent thread on affordable 12v battery replacements using sealed AGM batteries, you can go big or small.
     
  3. afia2k8

    afia2k8 Junior Member

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    2006 Prius
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    Sorry for the belated reply. It's most likely i'm not driving it enough. I've been driving it around more often now and touch wood, it hasn't failed me anymore. I saw Britprius post but doesn't seem like the sell those in the UK anymore.

    Just to add, if anyone in the UK is looking for a Prius gen 2 replacement 12v battery. I've found out that they use a Type 155 battery. Don't go for Eurocarparts, their recommendation is super expensive. Best compatible batteries are (both around £55 delivered):
    1. Bosch S4 022 Type 155 330a 45ah - 4 years guarantee
    2. Varta Blue B33 Type 155 330a 45ah - 4 years guarantee

    Note: Even though these are maintenance free, in an accident they may leak apparently.

    It's been said that you won't have a problem if you use the official Sealed AGM battery from Toyota dealership, which costs roughly £125 fitted for a 12v battery replacement.
     
  4. Naurill

    Naurill Junior Member

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    I have just replaced mine (myself) for the second time (after a further ~40k miles and 4 years) with a dealer supplied battery for 123.44 GBP (inc. VAT). The dealer in Southampton (Hedge End) had one in stock when I called in the day the old battery failed.
     
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  5. bisco

    bisco cookie crumbler

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    how much was it?
     
  6. Naurill

    Naurill Junior Member

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    As I said £123.44 inc. tax.
     
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  7. chronon

    chronon Active Member

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    i tried a cheap lithium iron phosphate and thought it was great .. but the drop off is not good and not sure it was holding according to its ratings .. a reasonable glass mat is the way to go because that was the design thing and it can hold up the current and doesnt have the weight of lead acid, and the size .. if u were to get an SLA lead acid it likely wouldnt fit in that teeny tiny most difficult of access areas ...
     
  8. Naurill

    Naurill Junior Member

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    It seems that the dealer price here in the UK (nearly) prices in fitting.
     
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  9. Naurill

    Naurill Junior Member

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    Oh, I should have said that the battery well was superficially rusted after my repair of 4 years ago, so I will need to apply some rust treatment/primer and paint to ensure it does not get any worse.
     
  10. bisco

    bisco cookie crumbler

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    thanks i missed that.
    that is a good price compared to over here