And despite both sides having a number of opportunities to snatch the win after the break, neither managed to find the net.
A deflated Davey, who had watched his side end a 26-year losing streak at Hillsborough with a 1-0 win over Sheffield Wednesday in midweek, admitted his side had not been at their best.
"It was a missed opportunity to get three points and it ends up a point gained," he said.
"We didn't play well on the day we know that and we were poor but we ground a result out.
"Perhaps two or three weeks ago we'd have given a chance away and they'd have gone away with the three points but it was a difficult day with the conditions, the wind was terrible, but at the end of the day a draw was probably a fair result."
Davey admitted expectations were high after the Tykes' first win at Hillsborough since 1979 on Tuesday night, but said he never expected Charlton to roll over.
"If we were going into the Sheffield derby and said we'd be taking four points out of the next two games we'd have all been happy with that," he added.
"It was a fantastic result and performance against Sheffield Wednesday on Tuesday night and we've come home and the expectation level is that we're going to walk all over Charlton because they're bottom of the league but that doesn't happen in football.
"And they've come here and set up very defensively with two banks of four behind the ball and they were hard to break down - it was difficult. It wasn't a pretty game for any of the spectators."
Davey went on to say they his side were under no illusions as to just how badly they had played but were relieved to have picked up a point.
"Four points, two clean sheets, one fantastic performance and one performance where we've come up with a draw," he added.
"We know, we've not gone in the dressing room thinking that is a great result, we should be winning our homes games.
"As a manager, player and staff we know we haven't played well but we've come out of it and have got a point."
Charlton boss Phil Parkinson hailed the "spirit and desire" of his players after they came close to winning on the road in the league for the first time since September 16 when they beat Doncaster.
He said: "There are a lot of positives for us, the attitude of the players was excellent and we looked a strong side.
"There were no weak links and we looked a strong and resilient side and we had a couple of chances to go and win it but it just didn't quite fall for us.
"But all in all i can't have any complaints about the spirit and togetherness of the team today."
Parkinson believes his side are an improving unit and pointed at successive clean sheets as to one of the reasons why.
He added: "When we beat Palace three weeks ago and lost a few players it set us back again and we lost two games on our travels, but we bounced back again against Plymouth and today and that was two clean sheets on the bounce for us.
"They are hard to come by all season and if you want to win football games you have got to have a solid base to go and try and win those games and we are starting to look a solid team.
"Of course we came here to win the game and in the team meetings leading up to the game we said we were going to approach it like a home team and step on to Barnsley all over the pitch, and be as positive as possible all over the pitch and that is exactly what we did."