You may have bought an HP-41 in EBay, just to find that the battery bay is utterly rusted. There goes your investment! Maybe you wanted it for CL conversion - maybe it was your first 41c and you wanted to see what’s all the fuss about it!
Whatever the reason, letting the rust inside your calculator is a recipe for later disaster. It will corrode the circuit lines, communicate to other parts of the circuit, destroying your investment (and, in the case of the CL, it IS an investment!)
You can easily buy port covers, even battery cover; but it is much more difficult to find this piece in internet. And with a good reason: it is the first thing that fails in the HP41c, and therefore you can only salvage the other parts.
Well, there is an option: you can buy in our shop the adhesive circuit that adapts to the plastic body of the battery connector. It has an extremely strong bonding, and the shape is perfect for the task. I have to say that it is a little difficult to put it properly: you need a firm hand and some experience to do it. I would not recommend to buy one to repair your only calculator, since it will not work properly the first time. At least it did not work for me the first time, but I got the experience of what failed. The second time went well already. So, my advice is: if you want to repair just one calculator, you’ll be better off buying two. If you’re repairing more, then n+1 - so that you can afford one error. Or you may be more skilled than me - in than case buy just as many units as repairs you need to do.
The circuit comes with clear repair instructions, but I would stress the fact that you need to bend it properly to shape beforehand, using the guidelines, and that you should start in the cavity between both ports.
I have used it to repair a calculator that would not start, and that I bought in internet as “for parts”. Now it is my CL. Today I have just repaired a non-working CV - this time keeping the original board in. This will end up in another CL as soon as I receive the new boards, with Sandmath 2x2, among other new features.
Please take a look at the beautiful finish of the battery once repaired.