Tennis tutor external battery packs:

[dman72]

I have the original tennis tutor machine. I just picked it up for dirt cheap. The built in battery is totally dead, it's about 10 years old. Can I still use an external battery pack? Does it just plug into the charger hole? I'm willing to change the internal, but I'll avoid it if at all possible. Is hard to change the internal batter? Thanks.

[mark rodgers]

It's easy to change the battery if you have some basic tools. You'll need an allen key to unscrew the screws around the middle of the machine. There are also two small screws on the side that screw into a support that's on the inside. Note where the different length screws go. Get a piece of paper and write it down if you have to. On the control panel you only need to undo the two top-most screws to release the top half of the cover. When you're lifting up the cover, you'll need to disconnect the wire that goes to the ball hopper. Just pull up on the top half of the machine slowly and look underneath. You'll see where you disconnect it. When you're inside you'll see the batteries. I've only owned a model with two batteries. I'm not sure if they even make it with just one battery. You can figure it out from there. If there are two batteries, just note how the wires connect to each battery. That's very important. Overall, it easy. I think it may take you more time to go to the electronics store and get the replacement batteries (about $20 each). Oh, one last thing: make sure you get the same size connector posts as the original battery. They come in different sizes. Take one of the dead batteries with you when you go to the store.

[firstblud]

sorry to hijack this thread, but is it as much work to replace the battery for a tennis tutor model 2 machine?

[mark rodgers]

I'm assuming that all Tennis Tutor machines have the screws that hold together the two halves of the cover. You only have to remove those screws and separate the top from the bottom half. You can also remove the bottom of the ball hopper by removing all the screws that hold the ball hopper flaps in place. But it's a little more difficult maneuvering to be able to remove the batteries and putting it back. I've tried it both ways and removing the top half is the much better way to go IMO. I was only trying to be as detailed as possible for such an easy task.

[dman72]

Let me tell you that it is not THAT easy to remove the cover. My machine had this weird round nut connected to the last bolt that I had to reach inside the machine with pliers to hold while turning the allen key. Then, removing the battery cover is not easy without long deep socket wrenches. It took me more than an hour. I guess it beats having to pay $800 for a new machine, but still.

The type of batteries (2) in mine were pro-sonic 12 volt 7.0 amp hour sealed lead rechargeables. I ordered them online for $36 for both, including shipping. The LOOK like the same connectors..I'm hoping if they aren't I can rig it up to work. The local place here wanted $36 a piece for the batteries...

[mark rodgers]

Congratulations! Aren't you glad you finally did it? Yeah, it's a bit of a pain but not that hard do to with some standard tools. And now that you've done it, it's no longer a mystery and you can now replace any defective part.

If the posts on the new batteries are too big, just get some wire cutters and trim the post to size. Don't cut them too small because they'll need to fit snugly so that they don't slip off.

[dman72]

Originally Posted by mark rodgers

Congratulations! Aren't you glad you finally did it? Yeah, it's a bit of a pain but not that hard do to with some standard tools. And now that you've done it, it's no longer a mystery and you can now replace any defective part.

If the posts on the new batteries are too big, just get some wire cutters and trim the post to size. Don't cut them too small because they'll need to fit snugly so that they don't slip off.

Yes, I'm glad. I hope that everything works after the batteries are in and I put it back together. Should I just order and replace the wheels now? Is there anything else that I might have to replace that I should just do now?

[volusiano]

Originally Posted by dman72

Yes, I'm glad. I hope that everything works after the batteries are in and I put it back together. Should I just order and replace the wheels now? Is there anything else that I might have to replace that I should just do now?

Are you talking about the internal wheels that shoot out the balls, or the outside wheels that the box sits on? If the internal wheels, I'd just try it out first to see how well they shoot. While the box is still open, I might sand paper them a little bit if they feel too smooth so they can grab the balls better.

When I took my box apart and put it back together, there's a little rubber chute where the balls fall into when they go down the hole. Make sure this rubber chute rest on the metal guide and not under it. I inadvertently had it under the metal guide and my balls just didn't shoot out properly. Took me a while to figure out what went wrong. Just a very simple thing not in the right place, but easily overlooked.

[dman72]

Originally Posted by volusiano

Are you talking about the internal wheels that shoot out the balls, or the outside wheels that the box sits on? If the internal wheels, I'd just try it out first to see how well they shoot. While the box is still open, I might sand paper them a little bit if they feel too smooth so they can grab the balls better.

When I took my box apart and put it back together, there's a little rubber chute where the balls fall into when they go down the hole. Make sure this rubber chute rest on the metal guide and not under it. I inadvertently had it under the metal guide and my balls just didn't shoot out properly. Took me a while to figure out what went wrong. Just a very simple thing not in the right place, but easily overlooked.

I saw that when I took it apart...it looks like something that you could easily mis-align when putting it back together that could really screw it up.