Need a new 36v battery for my bike.

[Synthman]

Following on from this thread: http://www.pedelecs.co.uk/forum/electric-bicycles/9900-battery-cutting-out-higher-voltages-symptom-failing-battery.html

I would like to get a new case, but if not I will reuse the current one. Here's some pics of the dimensions, how it slots in under the seat, and inside the battery pack. The block of wood is there because there's an empty space on the side, the packs were originally stuck in on one side only which was totally inadequate and caused me loads of problems.





Here's the only pack I've found so far that will fit: 36V 10Ah Lithium Ion Electric Bicycle Battery Pack - BMSBATTERY

Will be happy with 10-15ah.

 

[morphix]

Following on from this thread: http://www.pedelecs.co.uk/forum/electric-bicycles/9900-battery-cutting-out-higher-voltages-symptom-failing-battery.html

I would like to get a new case, but if not I will reuse the current one. Here's some pics of the dimensions, how it slots in under the seat, and inside the battery pack. The block of wood is there because there's an empty space on the side, the packs were originally stuck in on one side only which was totally inadequate and caused me loads of problems.

View attachment 2871
View attachment 2875
View attachment 2870View attachment 2872View attachment 2873View attachment 2874View attachment 2876

Here's the only pack I've found so far that will fit: 36V 10Ah Lithium Ion Electric Bicycle Battery Pack - BMSBATTERY

Will be happy with 10-15ah.

I have that very battery myself from BMS, had it a couple of months (10Ah). So far so good, its powerful and a performance improvement on my LiFePo4 5Ah battery without much weight/size gain so I'm very pleased.

 

[Synthman]

I have that very battery myself from BMS, had it a couple of months (10Ah). So far so good, its powerful and a performance improvement on my LiFePo4 5Ah battery without much weight/size gain so I'm very pleased.

Cheers. What range do you get on it?

I took some more pics of the bike, where the battery mounts, and the battery. The mounts are screwed to a plate attached to the frame. There is a rubber pad at the bottom where the battery sits. The battery will have to be the no bigger than my current case, or it won't go through the frame at the top. Also the pics show how the compartment is exposed to the outside. The power cable is tied to the frame, and is easily moved if needed.

Battery compartment:


Battery:


This is what my battery read after several trips today, 8.5 miles total. Reckon I had at least 2 miles left, and it was fully charged yesterday to 41.9v. It did not cut out.

 

[Deleted member 4366]

This one comes with a similar fixing arrangement. You might be able to fix the plate where your existing one is. If not it should be simple enough to fix it to the two frame members on the side oposite the chain by drilling some holes and cable-tying it, or use pipe brackets. I'd go for the 15aH one because the difference in cost from the lesser ones is small compared with them.
36V15Ah Li-Ion Alloy Shell EBike Battery Pack - BMSBATTERY

 

[Synthman]

If those are the exact correct measurements listed there, it won't fit on the existing plate because it needs an extra 4cm between the frames. There is also 2 rubber things under the seat that rest on top of the battery. I'm worried if it doesn't sit on the battery properly I'll go through it if I hit a bump.

The other thing is it's not clear how the battery slots onto the holder, and in the picture, there's a hole in the bottom right. I think it's so the battery can be locked to it. Only problem is the key will be difficult to operate in the compartment. If I attach it to the side frames, would I weaken it by drilling holes through? I'd also have to make sure it's centred in the compartment. I have a lot of sheet metal I could use in the process though.

I'm going to try contacting them for more info on the dimensions, and for more pics of the battery and holder.

 

[Synthman]

Using my initiative for once, and Google too, I found some pictures of other makes of battery with the same case that answer my questions.

1: The connector to the bike is on the underside of the battery, the side where the key is. This will cause problems, as if I have the connector on the underside, it will work loose when riding. Not just that, it is the wrong connector, that has a female IEC connector, whereas my current battery has a male connector, and the orientation of the middle pin is different. I could turn it upside down, providing it won't damage the battery, and if it will slide in from the other end. The battery is designed to mate with a housing at the bottom. if I had that, it wouldn't work as the battery would be too tall and the seat wouldn't close.

2: It has a key to lock it to the battery mount plate. I don't know what else it does. If it has an ignition too, more problems I don't need. I would snap the key off in the ignition barrel, and leave it permanently switched on, but then it would be permanently locked to the bike?

I wish they'd do another shape more similar to mine, would save so many bloody problems man.

Endless-sphere.com • View topic - Empty battery cases...
If I could get empty Ezee bike battery case, or the Izip caes, they look like a good match for mine. At this rate it's looking like I will be buying the 10ah pack and using the old case. If I had spare cases I'd have multiple batteries in the unlikely event I need to make a long journey.

I thought mobile phones and .mp3 players were ridiculous with the myriad of different battery and charger connectors, but looks to me like ebikes are the same. They would all benefit from more standard sizes and connectors, but it would probably never happen.

 

[Scottyf]

If they all used standard connections then there would be no need to buy the over priced brand name batteries for a model bike.

That's the reason it's done that way.

 

[bode]

That's also the reason why so many people go for a replacement battery sitting on the back carrier; an effective if inelegant solution.

Incidentally, I have adapted my empty battery case (stripped of its cells by the bike's previous owner) to be a lockable home for my tool and puncture repair kit and pump.

 

[morphix]

Cheers. What range do you get on it?

I haven't had chance yet to test to its limits, but I can tell you the range is EXTENSIVE. To give you some idea.. I always pedal on full power pedal assist or throttle-only full power. I do a 4-5 mile round trip every day pedaling one way and throttle only the way back, normally that would empty my 5Ah LiFePo4, and I'd be showing 50% power mid way... With the 10Ah battery, the battery indicator doesn't move from full unless going up a hill. I can do the same trip twice on a single charge.

I also recently did about 18 miles doing mostly pedaling on full power, it hadn't seem to affect the power it was still reading full when I returned home. I used to get 18 miles out of my 5Ah on pedal assist full power before it was empty. I reckon then 10Ah would give me 36-40 miles or more if I stayed off the throttle.

I will have to reset the distance meter and test it out by cycling round and round, wouldn't want to get stranded!

 

[Synthman]

If they all used standard connections then there would be no need to buy the over priced brand name batteries for a model bike.

That's the reason it's done that way.

Yep, this doesn't just apply to bikes either, but practically anything from razor blades to phones.

I haven't had chance yet to test to its limits, but I can tell you the range is EXTENSIVE. To give you some idea.. I always pedal on full power pedal assist or throttle-only full power. I do a 4-5 mile round trip every day pedaling one way and throttle only the way back, normally that would empty my 5Ah LiFePo4, and I'd be showing 50% power mid way... With the 10Ah battery, the battery indicator doesn't move from full unless going up a hill. I can do the same trip twice on a single charge.

I also recently did about 18 miles doing mostly pedaling on full power, it hadn't seem to affect the power it was still reading full when I returned home. I used to get 18 miles out of my 5Ah on pedal assist full power before it was empty. I reckon then 10Ah would give me 36-40 miles or more if I stayed off the throttle.

I will have to reset the distance meter and test it out by cycling round and round, wouldn't want to get stranded!

That's good, I should get at least 20 miles on the 10ah, more than enough for me, and maybe I will finally get the original quoted range on my bike.

Would still like to find an empty case/cases to use though. If anyone knows where to get them, or has any spare, please let me know.

Ataching a pic (yeah, another one!) showing why I can't put it on the rack! Yes, that is a 20 litre microwave oven, not the standard smaller ones!

 

[morphix]

Yep, this doesn't just apply to bikes either, but practically anything from razor blades to phones.

That's good, I should get at least 20 miles on the 10ah, more than enough for me, and maybe I will finally get the original quoted range on my bike.

Would still like to find an empty case/cases to use though. If anyone knows where to get them, or has any spare, please let me know.

Yes 20 miles should be easily possible I reckon, if you pedal a bit. Another good thing I've noticed about the BMS, it just seems to handle big current draws like hills much better. Doesn't struggle and maintains a good speed all the way up.

I honestly don't you think you'll need to bother with a case if it's going under your seat. The BMS Lithium-Ion batteries come incased in this thick black plastic skin which feels pretty strong to me and also looks very professional and neat. I'm not sure it would withstand a drop onto the road at speed, but it would certainly be waterproof/puncture proof and take a few knocks.

Getting a case for my 5Ah battery was a long time obsession for me. I spent hours and hours looking but couldn't get anything the right size for a reasonable price... so when I saw the BMS battery I was delighted. It just went straight into my handlebar bag.

 

[Synthman]

If you look at the second set of pictures I posted, you'll see that the compartment is exposed to the elements, and battery needs an attachment point to keep it secure.

The original quoted range was 25-29 miles on a 10ah battery, I would have expected the lower estimate of 25 if they gave me a battery that wasn't nearly 3 years old at the time.

Only reason I wanted a case was to make a new pack right now to use, and carry on using the old one too. Since I can't find one, I'll use the battery a bit longer until it doesn't meet my needs (probably sometime next year), then gut the pack and put the 10ah pack in.

Ripping the old pack out and putting the new one, and making 4 connections sounds a lot easier than modifying the current attachment fixings and having to make new connectors for an ill-fitting battery.