Prius Auxiliary Battery Check Problem

[avensus5]

I am owner of Prius 2004 NHW20R and would like to know information on how to check the Auxiliary Battery. Note that the owners manual only provide details of how to clean it. What do I need to do to check the volatge of the battery and how is this performed. Appreciate details of precautions including disconnection requirements that should be followed to do this check.

[joedornan]

I believe you can see this info by engaging the service menu. You can do this by holding the "Info" button down on the centre console while turning the lights on and off 5 times.

-Joe

[CPC]

Does anyone know how to engage the service menu in the 2002 Prius? I just replaced the aux battery and now the "red triangle of death" comes up in the display and the gasoline engine won't stay on. There is still power to the electric motor, and I can move up and down the driveway but of course I don't try to drive in this condition. I just need to know what's wrong.

Thanks!

[KM_salem]

I came across this site which shows some of the steps:
12 Volt (12v) Toyota Prius Auxiliary Battery for 2000, 2001, 2002, 2003 and Mazda Miata Battery 1990 + with free shipping to 48 states

He also claims that you can replace your battery with a Mazda Miata Battery.

Good luck.
KM