A few fellows are using the 18V from Harbor freight and it works well, just a little heavy. I'm still using the standard setup offered by Sullivan which uses twelve 1.2V NiCads for 14.4V. It will start anything up to a 1.80 Saito with ease. By now you must be tuned into the fact that it's not your starter but rather the battery. Time to upgrade!

Best of luck.