What batteries do in need for a Euclid r-15
Welcome to HEF! Not sure if you’ve got this in the right place or not.
Euclid can be a little tricky, Like the R-35's we had used a model number of 74TD. Any chance you have more numbers they made 15 ton trucks from 1936 with a model of FD up into the 1960's and TD models from mid 1940's up to early 1950's. If not being concerned with keeping it original I would be looking for numbers on generator and regulator and see if someone can tell you what voltage they are and also see if there is a tag on the starter and go from there. Not sure how much one has to post here to be able to post pictures but maybe someone can let you know and then you could post a couple pictures of this truck.