Hello Robjev04, Thanks for your question on the RYOBI OP4040A-03 40-Volt Lithium-Ion 4.0 Ah Battery and Charger. To obtain parts please contact our Ryobi Customer Care line at 1-800-860-4050. Thanks for reaching out to us! - Eve
Hi HuskyinWA Thanks for your inquiry. All Ryobi 40V batteries and chargers are interchangeable with all Ryobi 40V tools. However, the charge time can vary. Normally charging time range from a minimum of 90mins up to 2 plus hours (depending on the temperature). Thanks for your question. Best Regards Thank you for contacting RYOBI, we apologize for the delay in response.
In general I agree with you; if I need another battery I always look for a combo deal and essentially get the other battery I need PLUS another tool at a heavily discounted (net) price. BUT, in this case, it's not so simple. I just bought the trimmer and it comes with a 2Ah battery, not 4Ah like the above. AND, this charger is more advanced, having a USB output for charging phones, etc. and the one that comes with the trimmer is the most basic charger - no USB, and presumably a more "plain vanilla" charging system.