What other 12V battery can be used in Is 300h 2014

LovingLexus · April 1, 2021

Hi

Car was standing for 2.5 month not started and now Battery fails if not started for 16 hours. Got 12V Battery checked at a dealer and they think its ok but that's typical dealers.

Charged already few times and also left few time for 60 min plus with nothing else but still goes flat after 16 hours. Can't think of anything else as it was perfectly fine before leaving the car for 2.5 month without starting as I was abroad.

Anyways decided to change or please suggest any other solution.

I see everyone recommending Lexus IS Phase 3 Auxiliary 12V Starter Battery which is genuine Battery but its out of stock.

I have spoken to 2 different dealer both saying its out of stock and both dealer said a normal AGM or non AGM Battery cant be used which am not believing but then checking on different parts site there is no 12V Battery listed by most other suppliers except Platinum Prestige Battery (30,000 Engine Starts) b030e 12v battery on some sites and Varta Battery on eBay.

So kind of confused where else can I get and what can I get.( specification) and is above ok

I have tried a normal non AGM Battery in Prius previously and it worked OK for years without trouble but just wanted to get forum opinion on it

Thanks all in advance.

ColinBarber · April 1, 2021

The only thing you could try is a Battery charger with an AGM (pulse) repair mode to see if it can restore some of the lost capacity (e.g. Noco Genius, CTEK, cheap no-name chargers from Amazon). In reality not sure how well these repair modes actually work.

All dealers seem to be out of stock of the replacement batteries - too many people have let their batteries get discharged over Covid lockdown and demand is outstripping supply.

You could use a standard flooded Battery (one with a vent hole that you can connect the vehicles vent tube to as the Battery is within the boot which isn't sealed from the cabin). As AGM batteries need a slightly higher charge voltage than standard flooded batteries the vehicle could slightly overcharge it, so you would want to check fluid levels every few months and top up with distilled water if needed. Using a flooded Battery means it cannot withstand being discharged as well as an AGM Battery and therefore you want to be more careful with keeping it charged up.

The challenge will be finding a Battery to fit. No one will list their flooded batteries as being compatible with the IS300h so you will need to take measurements of dimensions, terminal size/position and vent hole position to find something that will fit.

LovingLexus · April 2, 2021

Many Thanks,

Can’t find any batteries so far and current one dies very quickly so it not holding.

Have tried the repair function via amazon charger but no luck show fully charged and fixed but Battery dies again.

Not sure what to do.

Lexus should improve their supply chain as been told nothing for over a month now 😞

paulrnx · April 2, 2021

Maybe try a breaker? As long as the donor car hasn’t taken a hit around the Battery area.

LovingLexus · April 3, 2021

13 hours ago, paulrnx said:

Maybe try a breaker? As long as the donor car hasn’t taken a hit around the battery area.

Thanks but batteries at breakers will probably have same issue as that would be not charged for so long!

paulrnx · April 3, 2021

1 hour ago, LovingLexus said:

Thanks but batteries at breakers will probably have same issue as that would be not charged for so long!

It’s not really how long a Battery hasn’t been charged for. It’s whether the Battery is holding its charge once it has been charged. If it doesn’t hold its charge it is faulty. Or you have a fault in the car that is causing a constant drain on the Battery. You believe you have a faulty Battery so it would be worth trying to get a replacement Battery from any source. Got to be better than waiting a month or more for a replacement.

LovingLexus · April 3, 2021

1 hour ago, paulrnx said:

It’s not really how long a battery hasn’t been charged for. It’s whether the battery is holding its charge once it has been charged. If it doesn’t hold its charge it is faulty. Or you have a fault in the car that is causing a constant drain on the battery. You believe you have a faulty battery so it would be worth trying to get a replacement battery from any source. Got to be better than waiting a month or more for a replacement.

Fair point thanks , can you recommend any breakers in or around birmingham,