tomy gordon can't go up inclines?

Just an update on this, I was looking at C and AA size batteries and I noticed they have the same voltage. I put an AA into Gordon and he made it up. Barely though

I knew that they worked, they are actually the same size, however the C size offers better performance. I have a few locos that I use a AA instead of a C however I think it's important to make a spacer or else it may ge annoying to have to reposition the battery. I think the problem could be the wires between loco and tender, as if they are not long enough they could restrict the motion of the drawbar

I thought C was 1.2v like AA

[Super]

Unless you are using Re-chargeable Batteries (1.2v for AA and C) the non rechargeables should be 1.5v

Yes, I'm using re-chargeables