hi sages- this is probably a job for superdan our electrical sage, but anybody please feel free to speculate. im looking to buy a battery tender, not a trickle charger to keep my battery maintained for long periods of storage. have seen deltrans on the internet and was looking at one from schumacher called batterymaintainer. called their 8oo number to make sure it was a tender with a charge sensor and auto shutoff and to find out where it was made. about at the end of my rope with these cheap parts from the far east, particularly china. always thought schumacher was a a good product, but maybe times have changed. the company rep told me it was in fact a tender and was manufactured in mexico. what do you think about buying this one from schumacher. told me they had no reports of problems with it. cost about 24.00. also napa sells an aerosol for spraying battery terminals and clamps to slow corrosion, looks like aclear blue light paint. what do you think? let me know your take on this my wiser sages. thanks tons bob f