Got my new battery!

[Haku]

At last, I have managed to get a new battery from UrbanMover

It turns out the original 12Ah li-pol battery wasn't all it was cracked up to be - apparently the battery manufacturer (GE) admitted that it wasn't a full 12Ah and that there was a problem with the flat wire connecting the cells (burnt out due to over-ampage) and the maintaining circuit inside wasn't able to cope with the full ampage the battery can output, UrbanMover had to recall a large amount of the li-pol batteries.

The one I have been given now is a new 9Ah li-ion made by Panasonic but UM have in their tests been getting 10Ah from them so Panasonic have been understating the performance. They're also working with Lithium-Phosphate batteries because they can output much more amps than poly or ion types, meaning quicker acceleration.
Oh and they're doing away with key-switches on the batteries because of too many people losing them, now they just have a rocker switch.

My new battery is charging up right now and will be taking it for a burn sometime tonight but I probably won't get a full range out of it because it needs around 15 charge/discharge cycles to gain it's full capacity. He also gave me a new saddle after my original one took damage from my short trip over the handlebars.


The new UM36X is in a larger framesize (19" or 21") and matt black, partly because they couldn't sell the smaller frame sized bikes to the Americans, I didn't get to see one because the demand is outstripping supply, the dealers have said they don't want the silver/green ones anymore. Their website is getting updated over the next week or so and I'm looking forward to seeing it.

 

[flecc]

The one I have been given now is a new 9Ah li-ion made by Panasonic

I understand that Sanyo actually make Panasonic's lithium batteries, such are the convolutions of this industry.
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[Haku]

I got a pic of the new bigger frame UM36X:

I noticed something last night which explains somethnig that's been at the back of my mind ever since I got my UM36, after a ride I saw the LEDs on the battery were down to 2* whilst 3 were showing on the bike. Leading me to believe that the LEDs on the bike are tuned to measure the old 24v NiMH batteries whilst the ones on the lithium-ion battery are tuned for that 26v pack.
So to know what the status of my battery is I have to look at the battery

The new UM36X has a different, 6 LED battery level indicator which I don't think was designed very well, too big for what it is.

*there are 4 indicator LEDs on the battery & bike, 3 lit means full battery which progressively go out when the power is drained and the 4th lights up when the battery is very low (recharge time)

 

[flecc]

Good to hear you've got your battery. That X model is a very smart looking bike, quite stylish.

Battery meters are generally more accurate than bike ones, but they do need to register to zero correctly. As such they calibrate when the battery is first fully charged and then discharged to cut-out. That then sets their zero reference, but it can drift out over time. The general advice is to run the battery to empty once in a while, say every 40 or 50 charges, but the interval isn't critical of course.
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[Haku]

The lithium-ion battery I was lent didn't have a cut-out level, just once I ran it down till it could barely power the motor and the voltage was so low that it took a few minutes for the charger to begin charging it, I've not had this battery long enough to gage how low it can really go so haven't found out if it has a voltage point where it cuts the output.

The LED meters on the bike & battery use identical circuits from what I can gather, just that they're tuned to measure different voltages.

I've been thinking of temporarily sticking a multimeter on the handlebars so I can see a real number instead of a bunch of lights on the handlebars that lie to me, perhaps get something like this and mount it in a box on the handlebars:
Mini LED Digital Panel Amp Meter Voltmeter & Regulator on eBay, also, Generators, Home-Use, Tools, Home Garden (end time 20-Feb-08 01:02:09 GMT) just wish it could do more than 1 decimal place
Just waiting to hear back from UM about the level indicator problem.

*sigh* just when I thought things were going well


edit: found a panel voltmeter that can read up to 99.99Vdc eBay Seller: new2006power: 99.99Vdc, Electrical Test Equipment, DIY Tools items on eBay.co.uk

 

[flecc]

It's usually the remoteness of handlebar meters that makes them less reliable in practice, being more affected by the throttle etc. I don't think it matters from the meter point of view whether there's cut-out, just going to a low level can give a calibration point for indication to register from.

A two decimal place panel meter would be a good idea to give a more positive readout, but no volt meter check will ever be accurate due to non-linearity as a battery discharges. The only way to get real accuracy is the historic method, using something like the Cycle Analyst (DrainBrain) to indicate capacity based on previously collected experience. Expensive though.

Personally I find that the speedo's trip odometer is the most accurate when combined with riding knowledge throughout one's area, and I largely ignore the meter. Two of the most experienced in this field, Heinzmann and Giant, don't use handlebar meters, just battery ones.
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[MaryinScotland]

Oh and they're doing away with key-switches on the batteries because of too many people losing them, now they just have a rocker switch.

That's a bit sad. When I leave my bike parked, I lock it up carefully and of course I take away the battery key. But with the new system, could some passer-by who wanted to fiddle with it turn on the battery, twist the throttle, and have the motor flogging itself trying to turn the wheel against the lock? Bad for motor and for spokes, I would have thought.

 

[Haku]

flecc, that unit looks good but yeah it's a bit expensive just to get a highly accurate status of the battery, I'll be happy with something better than the 3 lying lights, like the 99.99vdc display which I'll probably get before too long.


maryinoxford, yes that's another down point for having a normal switch on the battery, the only way to avoid that would be to take the battery with you which isn't always practical, the first down point I discovered with having a normal switch is you're much more likely to forget to turn it off when you've reached your destination.

 

[Haku]

I still have the extra key switch tumbler & bike mount tumbler with keys I was given last year, the rocker switch uses the same sized hole as the key switch so could conceivably swap the rocker for the key switch some day.

Something even more interesting I noted was when I had a peek inside the top of the new battery pack is that approximately the top 1/4 of the pack is empty space, and the charger itself is only a few mm longer than the width of the battery, so I'd put money on the possibility of taking the charger out of it's case and mounting it inside the top of the battery!

 

[jac]

strange how a medium priced bike can use the panasonic batteries on their bikes presumably this is more or less the same battery that the biketec and kalkhof bike use would be interested in how much they cost

jim

 

[flecc]

It's a bit smaller at 9Ah Jim, and could be the one that used to be on those bikes. They now have the 10Ah.
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