To answer your question, yes you can.
Personally, I would disconnect the batteries after fully charging. Then check battery voltage after 30 days. If below 10.5 volts, recharge batteries and test again after another 30 days.
Below is a note sent to our field office every Fall.
Before placing the batteries into winter storage, make certain the electrolyte level is approximately 1" above the top of the separators. The electrolyte level in very cold batteries will be lower than normal, so let batteries warm to a normal temperature before judging electrolyte levels.
Once the electrolyte level is correct, ensure that the batteries are fully charged. Ensure that the battery tops are clean and dry.
Now, the choice is whether to leave the batteries in the vehicle or remove and store in a cool dry area. If the batteries are stored in the Vehicle, disconnect the terminal cables. This will prevent premature discharge of the batteries due to a ground in the electrical circuits, or failure to turn a piece of electrical equipment off.
If the batteries become discharged, the electrolyte can freeze when stored below +20° F. A 3/4 charged battery is in no danger of freezing. Therefore, batteries should be kept at least 3/4 charged, especially during winter weather. The frequency of checking batteries depends greatly on temperature.
A fully charged battery, stored at 80° F, will take 30 days before it self discharges 25 percent. At 50°F the time period increases to 100 days. This will give you an idea of how often a battery should be checked. Some makes of batteries will have a higher and some a lower rate of self discharge. This depends on the method of manufacture and purity of materials used.
Hope this helps.