You change polarity which can very possibly damage all electrical components.
The physical body of your DC Equipment is always your GROUND. This GROUND is where you also connect your -VE.
read the boring science book
In many cases, a ground symbol is used to save drawing extra lines in a diagram and/or to show that a metal cabinet is used as a return path to save wiring in the ground side.
The plus side of the battery has a NIPPLE on it. The negative side of the battery is flat. Hope this helps
Ensure you get the proper battery to replace the old one. Remove the nut and bolt that hold the stays of the old battery in place, then remove the plus and minus terminals (Need a 10mm open ended spanner generally) once all removed put in the new battery and connect terminals ENSURING that plus connector goes to plus terminal, after terminals connected replace the battery support stays and tighten, all done !
Perhaps you have to change the battery. It is also possible that the calculator is damaged.
There is a plus and minus side on all batteries to indicate the polarity of the battery - positive (+), negative (-), this way one knows which part to match with the device. Plus on the battery has to match the plus on the device and same for the negative in other for the device to function.
Very carefully pry open the remote. I took mine to " Batteries Plus" and the guy was only to happy to open it and install the new battery. He had a little special gadget.
You can wire two 12 volt batteries in series... Connect negative of the first battery to positive of the second battery. That common connection becomes ground. The positive of the first battery becomes +12, and the negative of the second battery becomes -12. However, do not expect to be able to charge the second battery in a system designed for only one battery, such as in an automobile.
disconnect both cables from the battery and remove the battery hold down bracket, remove battery, put new one in replace the bracket, connect positive (red cable [end will have plastic cover with red plus sign on it]} first than the other (negative) one. your done.
A car battery warranty can be bought at the place you got your battery from. Plus you can also bring in old battery for core money.
minus