i have seen this nice battery around called the t-1248a. it's a nice battery for portable applications. it can be fond with a charger on ebay for 27$. should i buy it
there is no datasheet i can find. max i can do is link to ebay or this: http://www.alibaba.com/product-gs/283110784/Portable_12V_li_ion_Rechargeable_Battery_Pack_4800mAh.html
not much documentation
It would help if you posted a datasheet or a link. WTF is a t-1248a? You must decide if it will suit your projects.