geebee

With SLA batteries every time you drain them deeply (basically more than 50%) you reduce their life span and capacity.
If the batteries were regularly topped up at work I bet the batteries would still be like new.
Re the discussion on longer ranges in the future one of the riders at the endless sphere forum from memory calculated that the recumbent trike he has if run at 35 mph would have in excess of 100 mile range using LiPo or LiIon (can't remeber which) batteries that he is using.

Hoofer

Mongoose update:
I took the Walmart mongoose electric bike for a test run to see what the range is now, after about 20 weeks, averaging about 4 days per week, so around 80 round trips (around 7.3 miles round trip).
Last month the range was down to 4.5 miles, but the speed / performance over the 3.5 mile ride to work was not reduced from initial testing. Trip time was 13:08 last month.
Today's run to work, 3.5 miles, in 14:30. The time was significantly down from earlier runs, and clearly the speed was tailing off by the time I got there. I continued only another 0.1 mile before speed dropped below 10 mph.
So at 80 trips/ 80 charges, range is about 3.6 miles.
Initial testing with fresh battery in January showed 14 mile range at around 16 mph, with death over the next mile (=dropping down to 10mph).
So after 80 charges, range is down 76%.
I'm thinking I'm going to replace the batteries with a NiCad pack form batteryspace.com that goes for about $160. Supposed to be back in stock in a couple weeks.

stokell

I'm not sure if it's the battery or the bike, but even with an old LA battery, you should be doing better than that. I bought a brushless hub kit from Wilderness Energy that came with a 36 volt LA battery. I still have it but, wow is it heavy compared with the NiCads I bought. I found that during my 24 km (each way) run, the LA was pretty much done. I'd take the charger to work each time, but I know that's not good for a LA battery. When I got the NiCads the improvement was spectacular, the only thing is the batteries heat up with continuous use, so I have to keep them cool. I run them all the way down once a week. I've been doing this since late February and it seems to work. Now I just use the LAs as back up.

With the current bike I'm running I have a top speed of about 35 km/hr. It takes me just under an hour to travel the 24 kms.

Zeuser

SLAs will run down a bit and stay at a steady level for a while before they die down completly. I noticed this with my older eBike as well. Great performance the first few months and then it started degrading.

You also have to be careful with NiCads since they may develop a memory. I won't have this issue with my Li-Ions in my Bionx. But it's a bit early to tell.

Hoofer

I'm not sure about that.
The brochure says expected battery life is 3 months or 100 charges.

Actually, I think with lead acid batteries, the less deeply they are discharged, and the quicker you recharge them, the better. So you really should recharge them at work. I don't do so, because that would be a hassle.

Hoofer

My impression was that the performance (range) has been falling pretty linearly from the start - about 1% per charge, although I didn't do enough testing early in the first couple months to really say for sure.

I have heard that NiCads should be deeply discharged at least once a month.

I was thinking that the NiCads would have a similar, or maybe even a little better number of recharges/ lifespan as LiIons - perhaps 500. NiCads are bigger, heavier and worse for the environment, but significantly cheaper. Also the NiCad I'm looking at is rated at 7 amp hours, while the original SLA was rated at 12 Amp hours. I'm thinking that this is the best/ cheapest way to get the job done for the next year or so.

dwainedibbly

That's the same kit that I have. Did you get the 7Ah battery pack, or the 12Ah pack? I'm still using the 12Ah SLA battery pack that came with my kit. I ride 6.75 miles each way to work, recharging at home & office, so they don't get a deep discharge. I have noticed that my unassisted top speed is down maybe 1 mph, but it's hard to say for sure because it's been windy here the last month or so. I have ~1500 miles on these batteries so far.

Heavy? Yeah, these things define "heavy". I broke a couple of spokes on the rear wheel (I'm 195 pounds) then I rebuilt the rear wheel with DT Alpine III spokes and a Mavic A719 rim. No problems now. Still, when these batteries die I'll probably switch to NiMH batteries. If I do, I'll go with a lower capacity battery pack, too.

bugmenot

What's the current weight difference between your current SLAs and the nimhs you're planning to get?

Hoofer

Mongoose update:
I got my NiCad pack from batteryspace last week. I just got back from vacation, so I havent done anything with it yet. Hopefully over the next few days I will get it installed and have some data.

Hoofer

Mongoose update:
Well, I did get the new battery pack installed yesterday, and charged it overnight.
Seemed to charge ok. Had a red light in the afternoon, which had changed to a green light by morning. The instructions indicate this should mean that it has charged fully.
Commute to work was a bit disapointing
Rather than the mostly 16 mph cruise speed that the original SLA gave me, the NiCads topped out at 15 mph, and were notably more sluggish in acceleration than fully charged SLA. There was more traffic than normal this morning, so I had to wait at a couple stop signs that I usually can blow through, and I also dropped off a letter at the post office, which is on the route, but had to stop for a second for that.
Still, time in to work was 16:16, with average 12.9 mph speed, distance 3.50 miles. Not very good.
Also, at around the 3 mile marker point, I lost power entirely. This lasted about 50 seconds. I could still pedal fine, which I did, without much enthusiasm, at about 11 mph.
I'm not sure what had caused this. My soldering iron wasn't working right, so I could barely melt the solder and therefore my installation was rather shoddy, so maybe something was loose. I think there is a temperature probe built into the pack, so maybe that was the problem.
The battery was going flat on the way home, and I ended up going a total of another 4.5 miles before speed dropped to below 10 mph.
This was a more gradual decline in speed than I had seen with the SLA batteries, which would maintain 15-16 mph until the end, then drop to 10 mph over about a mile.
With the NiCads, my average speed each mile was 13.2, 13.1, 12.5, 11.6, 10.0, so tailed off slower.
Total range was therefore 8 miles.
I'm hoping things will improve after a couple charges.

evblazer

If the connection is shoddy it can really drop the voltage (making it perform like a discharged LA battery) and heat up at the connection (significantly decreasing range). Is the location of your connections overheating when you run? If it is really poor it could start melting stuff which isn't so good.
Might contact those that sent you the new battery. Maybe it needs a few cycles before it gets really solid performance. Even if it does need some cycles under the belt make sure your connections are good or it could destroy stuff down the road.
Of course it could just be the lower capacity of the new pack if you really did go from 12AH to 7AH.

Hoofer

Mongoose update:
Second day with the 24v, 7 AH Nicad pack.
To work 3.45mi. in 14:02, avg speed 14.7mph
Better than yesterday, but this was about a technically perfect ride (kept throttle nailed the whole time, didn't need to slow down for stop signs or lights, no wind), and still almost a minute longer than what I saw with the SLA pack.
Home - it went 3.5miles (of 3.75 mile trip) before falling to 10 mph
average speed per mile 12.2mph, 12.6mph, 11.7mph
So range today only = 7 miles.
I was hoping for slightly better peformance, but I guess that is the price I pay for going from the 12 AH SLA to a 7 AH battery.
If this performance is maintained over at least a few hundred charge cycles, I guess it will be adequate.

Hoofer

Mongoose update:
Sixth day with the 24v 7 AH NiCad pack.
Fortunately performance figures are looking up after a few recharge cycles.
To work 3.45 miles in 13:10, 15.7 mph avg
Home (longer route) 3.84 miles in 15:28
Total range ( =speed dropping to 10 mph) 9.8 miles

Lowell_

I ride my ebike through a local tunnel where regular cyclists have to use a shuttle which has a limited schedule, and does not run year round.

https://www.th.gov.bc.ca/popular-topi...sey/massey.htm

mike-on-da-bike

as petrol price rises and cities become more clogged up on the roads ebike will definantly grow,they are booming in sydney now,we have the most shocking public transport system at the moment,petrol is $1.50 per litre,rego is $1000,insurance another $1000, road tolls are become a silly price too,my ebike is my main mode of transport.price is not really an issue most folk will pay a good price for a good ebike as they do want an alternative to cars and slow public transport.owning a car these days just isnt the best option,we should also be looking at making hydrogen and electric cars now,its time to get off that oil treadmill and force the govs around the world to follow.we can make a difference today,not in 50 years time.

pengyou

I have been trying to read through this whole thread but have not been able to yet. Can anyone recommend a good place to buy a motor? Not a hub motor, but a motor that requires a belt or a chain? I am looking for a 350watt or greater that will run on anything from 36 volts to 72 volts