I have attached an external car battery to the Aux Battery. I intended it to be just until I could purchase a new battery, but now the wife says 'dont bother, just drive it as-is'. What kind of trouble am I asking for by doing this other than the obvious? Will charging be ok with a flooded battery vs the AGM? Here is the longer story: I have had my 2010 Prius since July 2010. I have replaced the Auxiliary battery once already. After I had that battery for just over 1 year, I started taking extended trips leaving my car at home. I noticed that if I didnt drive it for a couple weeks, I would come home to a dead car. You know the drill, crawling through the back seat to get the compartment open and attaching a power source just to get the hatch open. I first installed a battery-minder on an extension cord to the car while gone. It worked fine until a squirrel decided to use the cord as a food source while I was gone. I then purchased a small solar panel which I have mounted to the inside of the hatch window, This has been working flawlessly since I installed it in June '22. Last month, our Elantra needed a new battery, so I purchased a new battery and installed it. Days later, the engine 'blew' (Sounded like it threw a rod) and we decided to donate it, but keep the battery. So I think we may have left an inside light on overnight, and had a dead car the next day. I jumped with the spare Elantra battery and left the battery hooked up for my wife to run errands. I was planning to purchase a replacement today, but now my wife says she wants to keep the Prius using the jumped battery. If this is a viable long term solution, I will make properly fixed cables instead of the jumper cables now being used. I will also get a proper battery box since I dont want a flooded battery floating around the back compartment. I am not familiar enough with the Prius charging system to know if it can handle a flooded battery instead of the original AGM. Help would be appreciated.
Try charging the prius battery up. Do not run a regular battery attached to it full time. If you’re ever in an accident, that battery can become deadly.
If you play with fire, you're going to get burnt! Just having that acid filled battery sitting there is very dangerous. Even if it just flips over it will spill battery acid over your trunk which you or your wife touch and it will burn your skin, not fun! Get the proper battery and install it correctly. You could try a 4 amp agm battery charger that "might" give it some life. Depending on how long you've had it, there might be some warranty life in it. So you'll be able to get some money credit toward a new battery, if you take it back to where you purchased it. Is it a Toyota battery?
Patch or replace the cord? Any chance of garage parking? a plugged in smart charger is hands-down the best solution; just use it ‘round the clock during downtimes.
Taking AC to the car while away is not an option. Yes the cord is properly patched and used for temporary use. I still think the best long term solution is the solar panel. As for the flooded battery, I am taking precautions to prevent or at least contain any acid spill for the meantime. It's hard to save any money in this current economy hopefully enough can be saved to get the new battery soon. Battery is more than 5 years old and is definately bad. Battery is Duracell purchased +5 years ago. It is definitely not a viable battery. My solar charger has worked well over the past 18 months and there is no external cable and the car can be driven with it in place.
Buy a new battery. Buy the correct one. When it catches fire, your wife might not be the only one injured because of it.
Get a price of a replacement battery from Walmart. My local Walmart has one in stock for $160 plus tax. Fix it right and then forget about it for many years.
