I'm having some doubts about which batteries I'm going to use. I think I will run into some problems with the batteries I intended to use (CALB SE70's). There will be a box around them so that they're protected but they need some space at the top for connections and cables. In a few places I think this won't be possible in the frame. So I might have to go with different batteries.

Luckily there's a lot of choice, however the sizes are generally the same for all LiFePo4 batteries with same capacity. But there is one that might have the right size to fit in the frame (CALB CA60's).

Here are both next to eachother.

The paper models are all based on the blue CALB SE70's. The gray CALB CA60's are the newer types, these will fit as well but I'd have to place most of them on their sides instead of straight up. This shouldn't be a problem for these batteries, only upside down is known to be bad.

Few advantages of the CA60's compared to the SE70's:
- They're much lighter. In total 24 of the SE70's will weigh 60kg while 24 of the CA60's will weigh 48kg. That's a 12kg difference which would get the total weight a bit closer to original again.
- They won't need any cooling, even under heavy load. The SE70's though might need cooling.
- Under heavy load there's not much voltage sag, or in other words better performance since the voltage the motor can use will stay higher. With the SE70's there's a lot more voltage sag.
- Better performance with cold weather, for if I'd ever want to ride the quad bike below 0 degrees (C).
- Performance will remain the same, whether the batteries are full or near empty. With the SE70's performance will decrease gradually.
- They'll take up less space since they're smaller. They only have to be placed differently in the frame since they're higher.

The only advantage of the SE70's is the higher capacity so I'd be able to ride a bit further. And they're also lower so I could place them straight up which is always better. But well, it's not really that much of a problem.

Think I'll go with the CA60's now, will probably be easier to fit them in the frame with boxes around them. And maybe the range will be pretty much the same since the weight of the quad bike will be less.