12v battery alternative

PM'd you.

John (Britprius)

 

Yes but it needs to be within millimeters of the same dimensions (H x L x W) as the original.

Best Replacement 12v Battery: Duracell Procell SLI51

Final Cost: $98

Available at: Batteries Plus

This is the battery we used and (unlike the Optima which is both longer & taller) it is the exact same identical size. Plus you'll save $75 to $100 over the Optima. Additionally, no matter which battery you choose (with the exception of the $300 Toyota Battery) you'll need to change the terminals because the posts are fatter. We used an Autocraft marine battery terminal for the positive side (swapping out the butterfly nut for a regular nut) and an Autocraft 4 guage 15 inch battery cable for the negative side. Both from Autozone. Other than that we used 3/8 clear tubing and a sharkbite 3/8 tee (both from Home Depot) to vent the battery. We then sold the old battery terminals on eBay to cover the cost of the new terminals.

Here is a step by step instruction for a battery swap ~ this guy used the Optima so keep that in mind. Prius 12V swap

 

Almost every word of the above post are wrong for the US.
You need an externally vented AGM battery with JIS posts. Several are available.
It needs to be Externally vented and AGM as it is in the passenger compartment with your passengers. You can not ethically expose them to explosive Hydrogen gas or free Sulferic acid. The Prius expects JIS posts which are thinner and straighter than the more common SAE posts.
Batteries that are the right physical size are group S46B24R, here are several
Optima DS46B24R Optima battery direct fit replacement for Prius 2004 + , Prius V & Plug-in Prius with Instructions
Exide AGM Car Battery (Group S46B24R)
List: Battery - Automotive - 2010 Toyota Prius | O'Reilly Auto Parts
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Battery-NAPA-Legend-75-Month/_/R-NBE9851P_0396636574

In summary, safe, drop in, replacement batteries exist, do not use unsafe cobbled together Frankenstein arrangements.

 

Best Replacement 12v Battery: Duracell Procell SLI51

Final Cost: $98

Available at: Batteries Plus

This is the battery we used and (unlike the Optima which is both longer & taller) it is the exact same identical size. Plus you'll save $75 to $100 over the Optima. Additionally, no matter which battery you choose (with the exception of the $300 Toyota Battery) you'll need to change the terminals because the posts are fatter. We used an Autozone Autocraft marine battery terminal for the positive side (swapping out the butterfly nut for a regular nut) and an Autocraft 4 guage 15 inch battery cable for the negative side. Other than that we used 3/8 clear tubing and a sharkbite 3/8 tee (both from Home Depot) to vent the battery. We then sold the old battery terminals on eBay to cover the cost of the new terminals.

Here is a step by step instruction for a battery swap ~ this guy used the Optima so keep that in mind.

Prius 12V swap