Since the weight is in the trailer and not on your cycle, you can add additional SLA batteries to increase your range, and not change the feel of your ride.
The 12 Ah SLA battery will take you about 8 – 10 miles on a charge. Distance estimates are based on industry standard variables: 160 lb rider, 20 lb cycle, flat terrain, 70 degree temperature, no wind, cycle tires inflated to maximum, and one non-stop path.
To maximize your SLA experience, you can add a second charger, and store it in the Ridekick trailer for mid-ride charging or for workplace charging. In addition, the Y-cable can be added to connect TWO SLA batteries in parallel and give you a 16 – 20 mile seamless ride (no need to stop and swap the depleted battery for the fully charged one!)
Note: if you can find a local source or discount online, the specifications for replacement cells are 12V 12Ah deep cycle SLA batteries.
These standard batteries can be found with a search like “SLA 12V 12AH battery deep cycle”. This will point to many stores for batteries to power your ride.