Had an odd experience today. Part 1: Got in my 2004 Prius this morning (200,000+ miles), started fine after 10 days standing. Stopped at the local petrol station to check the tyre pressures and when I got back in it was completely dead. Not even a glimmer in a courtesy light. Got the RAC (UK) out who measured the battery and said it was only 8V. They connected their jumper pack to it and everything started. They then put the battery on their battery tester and it said “Blown cell” which he said needed a new battery which he didn’t have. Left his starter pack on and he followed me home. Part 2. Get home and he checks. £500 for them to replace it. He didn’t have the right one so rang up their local supplier who had a Yuasa one but £350. The local Halfords have one for £234 and online there is a Bosch (which is what is in there now) for £70. But everywhere seems to say Yuasa only. Is it that important? The battery only powers the electronics and 12V is 12V provided it fits in the space surely? Part 3: After he left I thought I’d connect a spare big battery to it for now as the boot/trunk won’t open from the outside without power and from inside is a real faff. Before I did I checked and the Prius battery was 11V - surely if a blown cell took it quickly down to 8V it’s not going to recharge to 11V in half an hour on a jump battery? So now it’s on my CTEK conditioner/charger to see if it recharges properly. And just wondering if I need a new battery at all and this blown cell stuff is wrong. The existing one is 2yrs old. Any suggestions? New battery or not and does it need to be a Yuasa at exorbitant cost? Thanks
Once the battery has dropped its voltage to zero, it will never be the same again. You can start the car once, twice, ten times. But you will still return to the same situation when you need someone with a starting device. Replace the 12V battery with a new one. The time has come. Any will do, but AGM technology is better.
Make sure that whatever AGM battery you choose has the vent fitting. You do not need hydrogen in your passenger compartment!
You want a battery that is the same as the original regarding: 1. Dimensions (height in particular is critical, with Toyota's hold-down bracket style*) 2. Post size and configuration 3. Vent port dimensions and location 4. Performance spec's (Cold Cranking Amps and Amperage Hours) (there can be some variation, but spec's simiilar to original are best) It doesn't have to be Yuasa, just compliant with the above. Do you have automotive retailers with interactive website, that'll allow you to enter your cars stat's, and show what they have that's suitable? Here in Canada, if I enter your make/model/year into Canadian Tire store's website, I see this: MOTOMASTER ELIMINATOR AGM Group Size S46B24R Battery, 325 CCA | Canadian Tire * Have some shim material and washers on hand when installing, the hold-down bracket is intolerant of any height variation.
That is the store brand for that Canadian store though. I have not heard of Canadian Tire outside of Canada. I used to shop there all the time. My youngest brother got a job at the auto parts counter while he was in high school. He progressed to the parts counter for their mechanics.This led to his job as the parts person for the mechanics for the Metropolitan Toronto Police. I think he is still working for them.
We do but I am not sure of one particular one I would trust. Walmart: Car Batteries and Accessories - Walmart.com Auto Zone: Car Battery - The Best Car Batteries at the Right Price NAPA Auto Parts: https://www.napaonline.com/en/shop/replacement-parts/batteries/automotive-batteries/315705179 Advance Auto Parts: https://shop.advanceautoparts.com/c4/battery/13646
It hadn’t dropped to zero. His meter said 8.something when he first connected it but the diagnostic report said 10V, although oddly it also says 0% charge. But either way it curiously didn’t even get a glimmer out of the courtesy light. In the past when I’ve left it for a long time it has dropped to the point where it will light the dash but not start, but never gone from lighting the dash and starting to 5 mins late absolutely dead.
Believe me, if the battery has dropped to 10V or 8V, it is already dead. State of health 0% You can try to revive it, but the sulphation of the lead plates has already taken its toll. The plates are covered with a grey mass, which will not allow the battery to work as it should. I knew people who drove with a dead battery for a year or two, using a jump starter to start it. But it is not at all convenient, and they later bought new batteries anyway.
Thanks. I do leave it often for weeks at a time while I’m away so thinking of doing the mobility battery hack because they are designed for multiple deep discharges. Any thoughts? Fitting mobility 12volt AGM battery. | PriusChat
The Ritar mobility battery has a vent in the same place as the OEM one and just needs a bit of tubing to adapt to the diameter of the Prius vent tube which is otherwise slightly loose fitting.
No Pb/Acid battery, AGM or otherwise, likes being anything other than 100% charged. "Tolerates" is a loose term and should not be construed as being it is okay to have an AGM in any state other than 100% or willingly allow it to deep discharge**. The longer a Pb/Acid battery (including AGM) is at less than 100% the more damage happens. The lower the SoC, the faster the damage happens. As you have a battery charger, use it any time your car will not be driven for three/four days or more. That really is your only solution unless you want to replace your battery frequently. ** If it should get deeply discharged, charge it up immediately.
For a long period of parking without driving, you can remove the negative terminal of the 12V battery. Constantly connected ECUs will gradually suck out all the energy even from a new well-charged battery.
I understand the newer models with the cloud connected services suck down even more energy when not in use.
Chargers are fine if you have it parked at home. But no good if you’re parked at the station or airport etc. And the other suggestion of getting in the boot/trunk with a spanner to disconnect the battery is not really a flier. Maybe I should just get a battery kill switch fitted to disconnect it and hope it doesn’t cause any glitches with the electronics when it powers back up.
Just realised. If I disconnect the battery terminal or fit a kill switch I’m going to have to climb in through the back seats to reconnect as the trunk/boot release requires power to it. Perhaps need to spend some more and get a remote control kill switch so I only have to go in that way if the remote fails.
