Replace rear pannier battery

[Peter.Bridge]

Hi all,

My 73 year old mother in law has always been a keen cyclist. She cycled miles (sometimes 50-60 miles) on an old, step through, very traditional and very heavy bike. Over the last couple of years she's done a lot less cycling because of her knees. I suggested a modern lightweight hybrid bike and she got a second hand boardman women's hybrid and gave it a try but she can't get on with the geometry so she is selling that one. She couldn't really afford a new step through e-bike and ideally it would be great to get one that could do 50-60 miles without "battery range anxiety".
There are some "quality" older step through e-bikes with rear pannier battery on Facebook marketplace / gumtree etc.
I've also seen rear rack batteries (with or without the fitting rear pannier) on Ali express with free delivery with 36v 20Ah (giving 42*20=840wah when fully charged?). They claim to be Samsung/LG cells. Could she buy a second hand older "quality" step through e-bike with rear pannier battery and I replace the rear battery/ pannier ? If it's the same voltage but larger capacity will that be a problem? Where is the battery controller generally - is that part of the battery housing ?

Thanks
Pete

 

[matthewslack]

A bit about terrain would be useful to know. That will guide choice to hub or midmotor. Also try to borrow and test ride to understand best suited motor type.

All range anxiety can be solved with a bit of planning and prevention. Plan a cafe stop, take a (preferably 4A fast) charger, have a leisurely lunch. The first few times, decide where in advance, call the cafe and make arrangements to have certainty. I quickly found I didn't need to.

If you have the charger with you, you are no more stuck than the nearest negotiable power point!

For independent 60 mile range, just get and carry a second battery.

 

[Peter.Bridge]

A bit about terrain would be useful to know.

She lives in Manchester, so some hills , but not many more than 10%. She's quite used to walking up hills pushing a heavy ordinary bike (so maybe walk mode would be useful)

 

[matthewslack]

There are plenty of knowledgeable people here who can guide from here: I'm mid-drive and get on very well with its riding characteristics, but mostly 10% gradients and less is ideal hub drive country, with benefits of lower cost, simplicity and so on.