This very interesting article was linkesd on Endless-Sphere. Basically. The Hailong case was only designed for 48v (65 cells). To get 70 vells in for 52v, the assemblers throw away the cell holding/spacing arrangement and bodge the cells in, which brings safety and reliability issues. If you want 52v, it's probably best to avoid a Hailong case.

https://www.empoweredcycles.com/blogs/news/52-volt-battery-proceed-with-caution

I've seen inside a couple of these and the cells were glued together and configuration was poor for current transfer. There is also very little room for a decent BMS, so these are often small and cheap and can be prone to failure.

Yeah, I wouldn't want to risk my house for the sake of saving a few quid. When it came to buying my current battery, I went for one from EM3EV, as they're regarded as providing top quality stuff. The one I went for was their 48v 15Ah 13S5P LG cell jumbo shark pack. Looks like they don't sell 48v battery packs any more, but it is very similar to the one in the link below:

 

https://em3ev.com/shop/em3ev-52v-14s5p-jumbo-shark-ebike-battery/

 

If you read the blurb in the listing, these are made with safety being a priority. My pack's been amazing, delivering usable power until nearly empty. Also, the bluetooth BMS is a great feature, which allows me to monitor the cells for charging/discharging and potentially storage over the winter.

 

For anyone reading this, please do not go for the cheapest battery you can find. Think about your and your family's safety.

Edited September 15, 20205 yr by Fordulike

Yeah, I wouldn't want to risk my house for the sake of saving a few quid. When it came to buying my current battery, I went for one from EMVE3, as they're regarded as providing top quality stuff. The one I went for was their 48v 15Ah 13S5P LG cell jumbo shark pack.

The problem with the 52v ones is that even the good battery assemblers have to bodge the cells in because the case isn't designed to fit in 70 of them. The only way to get them in is to skip some of the normal safety measures. Any case that's designed for 70 cells or more shouldn't be a problem.

The problem with the 52v ones is that even the good battery assemblers have to bodge the cells in because the case isn't designed to fit in 70 of them. The only way to get them in is to skip some of the normal safety measures. Any case that's designed for 70 cells or more shouldn't be a problem.

Totally agree. I was trying not to go off topic too far, but that blurb on the EM3EV listing does give some interesting info into why the Hailongs aren't a suitable casing for 52v set-ups.

 

Electric bike batteries are subjected to constant vibrations, which can break the internals over time. The more safety structures and safety features, such as cell fusing, the merrier.

 

My first ever Cyclamatic 24v battery had many problems, probably caused by constant vibrations. Twice back to the supplier and a few repairs by myself kept it on the road, but by default it was a poorly designed pack.

My first ever Cyclamatic 24v battery had many problems, probably caused by constant vibrations. Twice back to the supplier and a few repairs by myself kept it on the road, but by default it was a poorly designed pack.

They were happy days. Long live the Beastamatic. I still have a Cyclamatic battery under my stairs that I did some experiments with. Was it you who sent it to me? Is it the battery you mention? It came from somebody on the forum.

H

They were happy days. Long live the Beastamatic. I still have a Cyclamatic battery under my stairs that I did some experiments with. Was it you who sent it to me? Is it the battery you mention? It came from somebody on the forum.

Ha ha, the Beastamatic. That's going back a few years. Not sure if you got my battery, but I remember the biggest issue was one of the power leads, connected to the key switch, kept urrrm disconnecting. It went back to the Sports HQ twice for that problem.

I had one of those cheap Chinese Hailong 52v batteries on a recent build. I couldn't get it to work with my KT controller/lcd kit. Eventually when connecting it up in the off position one of the anderson connectors burst into flames. After that the battery wouldn't switch off.

I had just that problem with my 52v battery

https://www.pedelecs.co.uk/forum/threads/intermittent-fault-on-battery-causing-loss-of-power.35875/#post-533965

I now run a 48v battery