Hi Folks, I managed to get 6 years out of my stock battery (2016 IS350) and I am looking for a replacement. The easy solution seems to be to buy a Group 34 or a Group 24F Flooded Lead Acid battery with the posts in the right spots to not strain the cables and some time with a 10mm socket and ratchet in hand.

I was wondering if there is an opportunity upgrade to an AGM battery? The benefits being more charging cycles, deeper cycles, Longevity and lower self-discharging all in a sealed container.

In the second generation Toyota Tacoma's there is a particular Fuse to replace that increases the alternator charging voltage so that the AGM battery is fully charged and not damaged due to under voltage. In third gen Tacoma's, the alternator voltage is increased via ECU flash to support an AGM battery. The upgrade is done to power the fridges and lights on their overlanding rigs.

Before I pursue the AGM option, do you guy know if such a Diode or ECU flash exists on the IS350? Maybe other ways to support the charging Voltage requirement of an AGM?

 

Interesting question, would like to hear responses, as I just put an AGM (Optima RedTop) in my 2014 IS350, replacing the original battery (had served me well, but I let it go flat over the winter by not driving it enough and not on a maintainer while on vacation, which I’ve now added too).

 

I'm subscribed for a definitive solution as well. Here is one of the options I've seen for the 4runners:

https://www.arclightleds.com/collect...er-pg2tb-brs6a

Not sure if it would fit in the 3IS fuse box but this seems to be a popular solution among other Toyota models.

 

Ok, so that website says:“Odyssey states in their warranty booklet that:

‘…applications where an alternator is present, the alternator must deliver between 14.0V and 14.7V when measured at the Battery’s terminals.’ “

Unless someone knows, I’ll have to check this sometime (I know my other car with an AGM does indeed put out that higher voltage).

 

Looking into the tacoma forum a bit more and another thread mentions that the diode mod will work as long as it has the Toyota Alt-S Circuit. So....Here are the pictures of my fuse panel and the fuse box lid noting where the "Alt-S" is. The voltage at my battery terminals when the engine was running was 13.86V. In the Arclightleds board there are a couple of diodes like the diode mentioned on the tacomaworld site. So if the diode solution works, the output voltage at the battery when the engine is on should be at around ~14.5V if the turn on voltage for a diode is 0.7V. While I haven't tried this myself, the hints are looking good that this mod might work.

 

The Ford/GM diodes are a cheap way to find out if this will work. These are the part numbers I found on Tacomaworld (https://www.tacomaworld.com/threads/...ster.611314/):

Ford - 4z14a604aa
GM/AC Declo - 12135037

You can't control the voltage like the Arclight voltage booster but its the cheapest way to verify proof of concept. There is also no guarantee the Arclight booster will fit under the fuse box cover (the switch extends up and might interfere with the cover).

 

Just wanted to follow up on this thread. I picked up the ArcLight Voltage Booster for my 4Runner (when I eventually get an AGM battery for it) and figured I'd see if it fit in the 3IS. I also have an AGM in the ISF but I haven't taken it out of winter storage yet (will test that also).
Unfortunately, the ArcLight booster does not fit in the 3IS. The circuit board is oriented perpendicular to the fuse box, and as such, it does not reach the Alt-S fuse. Looks like the only solution for the 3IS is to get one of the GM fuses.

 

why are people putting a mercedes amg battery in a lexus?