As I have an e bike and love being out on it for some long rides, but then you remember about keeping an eye on your battery charge so you have enough

[m@Robertson]

Plan your trip properly. Your way out, make it all uphill, so it's all downhill on the way home.

Unless your name is Grandpa, in which case its snowing and uphill in both directions.

 

[Charles Kirkland]

Hello, new guy here, as well as e-biking. I Installed a motor kit without a battery and bought what I thought was going to be a spare for my trike. This 48v 14ah battery is handling my riding of both bike paths as well as the hike/bike trails that are dry and wide enough for me to get down. I want to get a spare now, is it worth paying in weight/money to go 48v 20ah? Thanks to any replies.

 

[m@Robertson]

Hello, new guy here, as well as e-biking. I Installed a motor kit without a battery and bought what I thought was going to be a spare for my trike. This 48v 14ah battery is handling my riding of both bike paths as well as the hike/bike trails that are dry and wide enough for me to get down. I want to get a spare now, is it worth paying in weight/money to go 48v 20ah? Thanks to any replies.

It is if the battery will fit (be sure of that) and you feel a need to go further.

Also a higher capacity battery (I'll argue you should always buy as much battery as you can afford) makes it easier to just charge the now-too-big pack to only 80%, which will preserve the longevity of the pack.

 

[Slaphappygamer]

At 20ah, I’d assume that battery would use 21700 cells. I have a 14ah battery and it’s made up of 18650. Just using 21700 cells should make a noticeable difference.

Yes, I agree, get the largest pack you can fit/afford.

Also, I might look into a 52 volt pack…..if I was getting a new pack anyway.

 

[Charles Kirkland]

Thanks, I have room to go bigger, at least to 20ah. If funds are available I'll look at 52v. I keep it on, or under 15mph, but there are some long stretches of road through the state park that I ride in and more distance before heading back sounds good.

 

[m@Robertson]

At 20ah, I’d assume that battery would use 21700 cells.

Not necessarily. I have 20ah packs that use 18650's and they aren't particularly large. Size is very dependent on what cells you use. Samsung 25R's in a pack make it capable of handling very strong output from a big-drawing controller. But the cells are not energy-dense so you need more of them to make up a pack. I've got one of those. Energy density versus energy storage used to be a classic tradeoff. You get one or the other but not both. Something like a Panasonic GA is a cheap cell that stores a fair bit more than a 25R, but its not good for high output so you seen them in packs that have BMS' with typically only a 30a rating. Samsung 30Q's were a prized compromise that gave you both, but ran hot. I have a 31ah pack with 30Q's in my 2wd hub commuter, and it fits into the bike's triangle.

If you can do it, 21700's are usually better choices for sure. But as recently as 2021 18650's were still what I needed to go to for a bigger pack. Mostly for economic reasons. You just couldn't get 21700's for reasonable prices. Thankfully those days are largely over.

Thanks, I have room to go bigger, at least to 20ah. If funds are available I'll look at 52v.

https://bicyclemotorworks.com is where I go to buy my packs, or have them custom made (I don't think he does custom work anymore). These packs are made to order (even the production models in the store) in the USA. I strongly recommend going up to 52v. Its almost the same peak voltage, compatible with 48v systems and gives you more usable volts. The power increase is negligible and only in effect for a short distance. Here again 52v makes it easier for you to charge to 80%. A 48v system is 54.6v at 100% charge. A 52v system charged to 80% is 55.4v, which is still more voltage than a 48v system so you have more range but can still do a limited charge to preserve your investment for longer.