Hi all, 2008 prius. Has been sitting since march 13 due to staying indoor because of covid-19. Before this it was my Lyft car and was incredibly reliable - probably 2000 miles per month. Had to go to the bank, so I went out yesterday morning and the car started up fine. I forgot something, so I went back home after going about 2 minutes down the road. Ran into my neighbor who wanted to talk so I got out of the car and went and chatted with him for about 10 minutes or so. When I got back to the car the gas motor was off and every light on the dash was on - including the red triangle. I ran into this before, so I put my charger on it (with AGM enabled) overnight for 24 hours. This was set at trickle charge - 2amps. I tried starting again this morning and same thing as yesterday - will not start and every light is on on the dash. I am not sure I got a good connection, since the needle on the charger said near 100% yesterday and was basically in the same position this morning. I reset the clamps, heard a click/hum from the charger and now the needle is at 60%. It is possible the clamps weren't sent correctly. When I reset the clamps I put the charger on medium - 10amps. The main battery meter in the prius dash is blue at slightly above half - FYI. My questions: - last time my 12v died, I do not remember the red triangle. Is this normal? Scared the hell out of me. - If I need a replacement 12v battery, anyone have directions on replacement? Recommend a good battery? - big Q - is 10 amp medium charge OK? Or should I go back to the 2amp trickle? Any comments appreciated, Rob
IF....the meter is actually showing the charging amperage AND that isn't over 5 amps or so initially, the higher setting should be fine. As long is it is dropping slowly after an hour or so. If it continues going UP, that is a bad sign. How old is the present battery ? It does sound like a bad connection might be at least a part of the problem. Once "running" the 12 V battery has to be REALLY bad before it will affect the vehicle operation.
I think second gen Owner's Manual recommends charging at 3.5 amp max? I would take a break from charging, at the very least measure the at-rest voltage, after the car's sat overnight, with a digital volt meter. For a better idea, test it with something Solar BA9. For replacement battery, Pep Boys used to have a Bosch, but they don't seem to be selling now. Maybe due to problems? Dealership part department is your most reliable now I'd think.
All kinds of weird stuff happens when the 12v battery gets into low territory, I've experienced this numerous times with a weary old battery. I reckon you should be fine after a good charge.
My manual says the same, however, there is a warning sticker on the OEM battery that cautions to not charge at more than 4.2 Amps. All the while the (non-OEM) AGM battery I have installed is quite happy to charge at 10 Amps – but my charger only does 5 Amps maximum.