Trunk Battery

[Daixiwen]

The 12V battery is not used to start the engine so you don't need a high cranking power. What it mostly needs to do is to provide enough power to the main contactor to connect the high voltage to the rest of the system and each relay coil uses less than one amp (DC resistance is in the 20 ohm region). So as long as the 12V battery can provide a couple of amps you are good.

 

[DaveL59]

Bear in mind too that a lithium battery can sustain a much deeper AH drawdown than a lead battery, so it isn't unusual to use a lower AH rated lithium battery to replace a lead one. For UPS's a 17AH lead battery can be usefully replaced by a 10AH lithium for the same runtime expectancy, since the lad battery voltage will have started to tail off once past the 50% capacity remaining level.

So using a 20AH lithium replacement for the OEM 40AH AGM doesn't sound unreasonable.

A more critical factor however is whether the BMS in the lithium battery can service the peak current demand from the load else the BMS could abruptly shut off the output so that's worth checking on batteries you want to consider using.

 

[LanderCT7]

S46B24L(S)
Standard battery fitted was the Yuasa HJ-S46B24L(S)
Terminal posts=T1 (Standard terminal post)
Cell layout = +ve terminal on right
Positive post = 19.5mm diameter.
Negative post = 17.9mm diameter.


S46B24R
The Yuasa HJ-S46B24R is a different fitment & not suitable.
Terminal posts=T3 (Small Japanese terminal post)
Cell layout = +ve terminal on left.
Positive post = 14.7mm diameter.
Negative post = 13.1mm diameter.

I got a 2022 US model from a dealer a few weeks ago. The battery in my trunk is the one in the link below. Weirdly, the website says it does not fit the 2022 Outlander PHEV. But it is the one installed.

I'm guessing the dealership replaced the original battery with this one at some point.

https://www.oreillyauto.com/detail/...tinum-agm-battery-group-size-51r/ssbq/51rtplt

Thanks. Similar, but here’s what comes up for my year.
https://www.oreillyauto.com/detail/c/acdelco/acdelco-battery/acd0/b24ragm

But still, the positive terminal post is on the wrong side, left when it’s supposed to be right. Yours has the positive terminal postOn the correct side, but more capacity than my car needs. Should I go with yours?

 

[LanderCT7]

Check out AGM battery size 51R. Dimensions and terminal layout fit, like this one ($240):
https://www.pepboys.com/fvp-agm-battery-group-size-51r/product/2802356
I don't think you can replace it with a regular (flooded) lead acid battery, the charging voltage is different.

Thanks. If I’m near pepboys I will check it out.