Any place to find a good replacement original DS battery anymore?

I have an original DS, and it's battery barely lasts an hour anymore. I can't seen to find replacements anywhere online, all of them are either for the DSLite, or DSi, which have very different batteries. There are a few really random ones.... mostly shipping from China or Hong Kong.... that seem really sketchy on eBay, but nothing that seems like it would last more than 6 months or not explode.

Does anyone have any suggestions on where I can find a decent replacement battery for the...

Any place to find a good replacement original DS battery anymore?