Mongoose CB 24V450 ebike - Minor issue this morning.

[sabrewalt]

Hello, Ran some store errands this morning on my stock Mongoose. At the end of the ride, I bumped over a little curb and I had voltage no more. Meter said that the battery case no longer was putting out so I took it apart and found that I had the positive to one of the batteries was disconnected. When I put it back on it was VERY loose. This was the first time that the battery case was opened. I tightened the connector with some pliers but on my next trip to hardware, I am going to get some clear silicone to help hold it in place. I you lose voltage on your be sure and check this as I bet I am not the only one who got one with sloppy connections.

 

[Elmweaver]

I have not had that happen yet. I have a lot of battery bounce noise though when I hit bumps in the road, I need to check inside my battery case just to make sure I don't have that happen to me out on the road.

Thought I would go ahead and post Reid's tips on this subject over into this thread so people might find it easier.

To forestall a problem you will run into otherwise: the weakest point of the electrical system is the plug in the battery box.

Its contacts are not really up to the current demands
--especially because vibration tends to work the plug loose.
What can and will happen eventually,
is that the plug works nearly loose,
and when a demand for 30+ amps occurs
(full throttle from a standing start, or going up a grade),
a flashover will occur---an arcing, then -poof-
one of the plug's internal contacts burns mostly away.

And then it's hard to get a contact--have to mash the plug in really hard.

This is a warranty issue if it happens early in the bike's life.
They sent me a whole new battery pack
(but I said that I needed a new plug and cord)
"We'll send you the battery pack too".

And it was a better battery box (has screws clamping its middle),
and that was great and all of that
---but the fools at Currie did not send the needed plug!

So I ended up hardwiring the box to the controller using Radio Shack's "Euro Style" grub screw connectors.

And so I made my own, superior fix.

So watch that plug--it needs to stay fully shoved home.
Check it during rough rides in case it may tend to jounce loose.
Mine sure did. The spring contacts lose pressure over time.

The bike in stock form is fine.
They all have their little problems, which are sort of fun to iron out.
Battery box--if it rattles it will wear badly.
Likewise, rattling batteries
in the box are a needless annoyance.
A -little bit- of urethane spray can foam injected into the box in several areas along the length of the box will lock the batteries in place.

Wedges of pine shim stock may be useful to lock the box itself from moving around. A dab of rubbery glue will keep the shims from falling out (which they will do otherwise, definitely)

Battery rattle is important to fix if you rough your bike on bad roads
or off the street. The case will wear its retaining groove badly.

 

[sabrewalt]

Thanks, I had not seen those tips. He is correct. The battery box does take a beating going over bumps and it make a lot of noise rattleing around. I have done about 25 trips since I got mine and it shows. I loaned it to my son who does not believe in going around anything on a bike and he HATED it. He is in such good shape however that he can cut across hill and dale and beat the Ebike to the same destination because of the nice roads that have to be used on the Mongoose.

One of the neat deals with buying these at Northern Tool is that for 50 bucks they sell a 1 time replacement warranty that lasts either 1 or 2 years. (I can't remember). You can beat the crap out of that bike and learn on it and then get a new one a year later at Northern's expense but only if something happens to the old one.(gets run over). My regular 3 month warranty is up about January 15th so I plan to buy one of those for sure.

 

[Lessss]

If your battery case ends in two terminals which sit on two terminals on the bike, I'd recommend soldering a couple wires to connect the terminals. That way you won't have power cut outs with every little bump.

 

[Elmweaver]

Ok, I opened my battery case and added some padding which has made all the difference. No movement or noise from the battery box now. I went for a ride and was even looking for holes to ride into so I could test it. :lol: :lol: :lol:

Here is what I did, I used some old 3/4 inch pipe insulating foam that I had laying around. I cut 6 inches worth into strips and inserted them into the battery box . Naturally I didn't think to take pictures while I was doing it. so I have recreated what I used and did in the photos below.

The yellow arrows show where a single strip was used, the red arrow is at the bottom of the case and the space there is twice as wide so I just doubled over the strip and it fit perfectly.

 

[Elmweaver]

BTW, while I had the case open I looked at the date and my batteries were made on 03/28/06. I bought the bike on 12/03/06 so they were 8 months old when I got them, wish I had a meter and had thought to do a voltage reading before they were used. I bet they were below the 2.1 volts per cell they should have been.

I think thats why I only got 2 miles from the first charge (they were charged before use) and also one of the reasons they only give a 90 day warranty on them.

 

[knightmb]

Wow, that's a great idea and so easy to implement. I'm thinking about replacing the two 12 volt SLA in mine with one of my 24 volt NiMH packs, but didn't even think about that part of keeping them from jumping around. Great ideas because my NiMH pack is much shorter than the two 12 volt SLA batteries. I'm also considering changing out the rear sprocket in the back with a larger one. That will change the ratio to one that is higher, so I should be able to get a higher top speed (shooting for 25+ MPH) at a sacrifice to some of the range if I don't assist along with the motor.

 

[Elmweaver]

I would like the higher gear not for the speed (sure I would use it sometime) but for the fact that I could go the same speed and use less energy from the batteries, meaning a longer ride distance.

 

[knightmb]

I think I remember somewhere on the old voltage forum before it got hacked, that someone did that with the same type of e-bike we have. I know a guy at my local bike store that also does that "custom" bike parts and he told me we can get anything. So I'll probably pop off that rear sprocket and ask him if he can make one that will fit like this one, only twice the diameter for example.

I'll have to get a longer chain, that's for certain. But in the end, it would be kind of neat to have an e-bike that only uses 24 volts but still goes fairly fast for the low voltage it uses.

 

[Elmweaver]

Yes I agree, I will let you be the test bike. Maybe it will not cost to much and I can follow along with that project later. Currie sells an 11 and a 15 tooth gear but I think they are for their scooters not sure if they would fit our motors which use the 9 tooth gear.

I think Reid did that to his didn't he, went to an 11 tooth gear made for him by Dom?

 

[knightmb]

Yes I agree, I will let you be the test bike. Maybe it will not cost to much and I can follow along with that project later. Currie sells an 11 and a 15 tooth gear but I think they are for their scooters not sure if they would fit our motors which use the 9 tooth gear.

I think Reid did that to his didn't he, went to an 11 tooth gear made for him by Dom?

Yeah, I'm hoping it will be cheap too. I'm hoping the bike guy can make me a 1 to 1 gear similar to what is on the wheel. Probably means it will need some assist from a dead stop, but once it gets going I wonder how fast it would go, :lol:

I can see the range test now, come up at like 5 miles distance before it dies. LOL

 

[Elmweaver]

No the length of time you ride should be the same as before only the distance traveled and the speed at which you did it should have changed. Your not making the motor go faster then you already do, so power usage should be the same only the wheel speed and therefore the max speed and distance should change, hmmm.

Unless it requires more power to get the same motor RPM's as your getting now at full throttle. It all comes down to the amount of torque available either from the motor or your pedalling or both. I think.

Once your up to speed as long as you stay there the amount of energy used should not have increased even though your speed has, unless you try to climb a hill which will require more torque and therefore more energy.

 

[knightmb]

Means I need a test track where I can go full speed without interruptions to get a range test. I actually have a place in mind. The local high school has a track that runs around the football field. Very nice and smooth pavement. If I go early on a weekend (or during the summer where there is no school), I should be able to make some laps around the place at top speed and see how far any of my e-bikes will go.