Husqvarna Aspire compact charger is compatible to charge both Husqvarna Aspire batteries as well as all 18V batteries within the POWER FOR ALL ALLIANCE system. For fast charging and with led indicator to see the charging status. The 18-B45 (2.5Ah) battery is ready to go with 80% charge in 40 minutes and 100% charged in 60 minutes. The 18-B72 (4.0Ah) battery is ready to go with 80% charge in 64 minutes and 100% charged in 95 minutes. This charger is a product of the POWER FOR ALL Alliance, one of the largest cross-brand battery alliances of leading manufacturers. These chargers can be used for all batteries that are part of this alliance. This means that you no longer need to buy one charger for every battery and product.