I have an original AIM Solo you can have for $100. It holds a charge for a full race weekend and works well.
If anyone is looking for a brand new SOLO2, MOTO-D has them in stock. Follow the link and use coupon code RYGUY4YA at checkout to get 10% off your entire purchase. Using the coupon or just purchasing through the link helps out a fellow WERA racer in the North Central Region. Thanks!! https://www.motodracing.com/?ref=Ryguy4ya