You basically have something that can charge up to about 45 volts reliably, but your bank, even depleted, will be above that. If you hook them in series and run them through a blocking diode and fuse to the battery, you may get a bit of power into the batteries on bright sunny days, but it will be less than ideal, and not permitted under the NEC in the U.S. as a charge controller is always required under that code. Generally, with this type of mismatch between panel voltage and battery charge voltage, an MTTP charge controller such as the Outback MX60 would be the answer, but that seems a bit costly and exotic for just the three panels. If you could come up with a 4th panel of similar current capabilities, then you can hook them in series and get what current they can output into the batteries through a 48V charge controller of most common types, or directly through a diode and fuse as I mentioned above if the batteries are of a type and sufficient capacity that they could handle the small current you would be getting. Rich