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The NiMh Radical Battery for the Torq
Warning: This alteration will almost certainly invalidate the bike and battery warranties. Do at your own risk. No responsibility can be accepted for any accident resulting from carrying out the modification described, nor for any technical problems arising on the eZee bicycle in consequence.
The battery used in the T bike makes a difference to hill climbing out of proportion to the ten per cent increase in voltage and motor power, due to the fact that the overgearing that's evident in the power to gearing ratio of the Torq motor is being partially corrected. It's self evident that the Torq's hill climbing ability would also benefit from using this battery. There are three ways of going about this, two involving extensive case alteration, the third making a minor addition to it. If you have the skills to expand the standard case by the width of a cell using the temporary mould and fibreglass layup method that I used, the result can be very neat and professional looking as you've seen.
The second way after cutting the battery case in half in the centre of the top section, and still producing a good appearance, would be to use pieces of plastic laminate like melamine equal to the width of each side's flat face but with height equal to a cell width plus a half inch/12 mm at both top and bottom to provide overlap. Then with the case halves screwed together, the laminate pieces can be stuck on with a strong epoxy adhesive like Araldite precision, secured by the overlaps leaving the cell width of expansion. After setting and parting the case halves, thin strips of laminate can be attached behind the side pieces, but protuding, giving the overlap case half joins. That leaves gaps at the four curved edges which can be filled with car body filler, then profiled to match the case curvature. The filler can also be applied to the cut case edges and against the laminate internally to give extra strength and rigidity to the join. Finally, rubbing down and finishing with aluminium spray will give a professional finish. If you're not sure of the aluminium spray variety necessary, they do vary in appearance, use Audi Aluminium Silver Metallic, available from car accessory shops like Halfords, this matching well. The finished join sits behind the slanting frame tubes which gives extra masking of any imperfections in your handiwork.
The third way if you don't want to modify the case so drastically is to use an external add-on which still permits use and charging as one unit, but also allows instantaneous reversion to using the standard battery at any time you require it. Most owners will probably prefer and use this method. For this you'll need the following items, all obtainable from Maplin in the UK and have the Maplin part codes shown. See later in the text for the cells to use.
BW 90 X XLR chassis socket. Quantity 1
BW 89 W XLR plugs Quantity 2
XS 92 P Twin 15 A cable Quantity 1 metre.
The battery used in the T bike makes a difference to hill climbing out of proportion to the ten per cent increase in voltage and motor power, due to the fact that the overgearing that's evident in the power to gearing ratio of the Torq motor is being partially corrected. It's self evident that the Torq's hill climbing ability would also benefit from using this battery. There are three ways of going about this, two involving extensive case alteration, the third making a minor addition to it. If you have the skills to expand the standard case by the width of a cell using the temporary mould and fibreglass layup method that I used, the result can be very neat and professional looking as you've seen.
The second way after cutting the battery case in half in the centre of the top section, and still producing a good appearance, would be to use pieces of plastic laminate like melamine equal to the width of each side's flat face but with height equal to a cell width plus a half inch/12 mm at both top and bottom to provide overlap. Then with the case halves screwed together, the laminate pieces can be stuck on with a strong epoxy adhesive like Araldite precision, secured by the overlaps leaving the cell width of expansion. After setting and parting the case halves, thin strips of laminate can be attached behind the side pieces, but protuding, giving the overlap case half joins. That leaves gaps at the four curved edges which can be filled with car body filler, then profiled to match the case curvature. The filler can also be applied to the cut case edges and against the laminate internally to give extra strength and rigidity to the join. Finally, rubbing down and finishing with aluminium spray will give a professional finish. If you're not sure of the aluminium spray variety necessary, they do vary in appearance, use Audi Aluminium Silver Metallic, available from car accessory shops like Halfords, this matching well. The finished join sits behind the slanting frame tubes which gives extra masking of any imperfections in your handiwork.
The third way if you don't want to modify the case so drastically is to use an external add-on which still permits use and charging as one unit, but also allows instantaneous reversion to using the standard battery at any time you require it. Most owners will probably prefer and use this method. For this you'll need the following items, all obtainable from Maplin in the UK and have the Maplin part codes shown. See later in the text for the cells to use.
BW 90 X XLR chassis socket. Quantity 1
BW 89 W XLR plugs Quantity 2
XS 92 P Twin 15 A cable Quantity 1 metre.
Start by removing the fuse, then unscrewing the two small screws that secure the battery base and sliding off the base as shown at the right. The case should be them be placed fuseholder side down and the three crosshead case screws removed. Then separate the upper case half and lay it along-
side. Whether you detach the wires from the charging socket or not in this next stage is up to you. What you have to do is cut out a hole for the XLR chassis socket in the small recessed part of the case that's alongside the charge socket, in such a way that the chassis socket sits between the charge socket and the screw securing post. Be careful if drilling not to split the case material. An alternative way is to use a clean hot soldering iron to melt cut an undersize hole, finishing it with a small half round file. Then mount the socket horizontally with the centre pin nearest to the charge socket, for which you'll need to chamfer a bit off the edges to fit into the confined area of the recess.
At the right you see the XLR chassis socket and the case recess with the rough position for the hole circled. Be careful to position the hole in such a way as to take best advantage of the area to fit in the socket mounting plate. As an alternative, the socket can be mounted in the larger recess on the other side of the case. To do this, after removing the three main case screws, turn it upside down
and lift off the fuse holder side to work on that. To have it completely free you'll need to disconnect the fuse holder wires this time. In this way of mounting it, make sure your socket position is not so close to the charge socket position that when the case is closed, the wiring between is obstructed.
With the socket mounted, time for wiring. Ignore the centre contact on your additional socket, disconnect the positive wires from the top end tag of the cell termination and extend them as necessary using a short bit of the cable you bought to connect to one XLR connection. Note down which one carries this connection that was from the positive cell end, and preferably mark it on the case or socket with a red label or paint. Now take a short piece of your cable and connect the other XLR connection to the positive cell end tag. Securely insulate all the joins made with pvc tape or self amalgamating tape. While you are doing this soldering, take one of the two XLR plugs that you bought, open it and solder a jumper piece of the thick wire across the two outer connections. This is your shorting plug, which plugged into the extra socket which will enable you to use the bike with the battery as standard without the extra cells.
That's the battery modification complete, so carefully reassemble it. If you wish to do this job by stages, the battery can now be used meanwhile by employing the shorting plug for both use and while charging. Since the XLR socket used is the same as the one used for charging, you must take care never to put a plug into the wrong socket which would result in immediate damage. You may wish therefore to put a clear warning marking on the battery. If you have access to a an alternative plug and socket system that fits, that would be preferable, but they must have a minimum 15 Amp capability if the performance is not to be impaired.
The Battery Pack
Time to discuss cells. The capacity you buy will be determined by the battery age and the use it's received. Over the period of the first 100 charges of an NiMh battery, the capacity actually increases slightly, then starts to tail off over the rest of it's life. Therefore, if your battery has had less than roughly 180 charges, buy the same size cells as the original ones, 9 Ah or if they aren't available, 10 Ah. If over that point and up to two years old, buy a size down, 8 Ah. If your battery is over two years old, it's not really worth doing this modification. If in any doubt as to what size to choose, always select the larger possibility. These loose large capacity Nimh cells are available from a variety of online sources, and come in two types, tagged or conventional positive button end. The tagged cells are easier to use, but also tend to be more expensive. Some suppliers such as Batteryspace in the USA also supply made up three cell packs. Whilst undoubtedly convenient, I'm given to understand that there are question marks on the quality control exercised by that supplier, so there might be a risk of a poor cell or two in a pack from there. If you have a suitable single cell charger when using those, use it to pre-charge the three cells.
If using loose cells, you can make them up in whatever format you find convenient to carry on the bike, tagged cells allowing more flexibility here, mounting in a box, plastic plumbing tubing or just bound together. If using button end cells, the only practical way is to strap them very tightly end on in a column of three, positive end to negative end in series of course. They can then be bound in card and again mounted as wished, a section on plastic plumbing tube being very suitable. Under no circumstances use a battery holder of the type sold by Maplin. The cheaply formed wire connectors in those are inadequate for carrying 15 Amp currents.
With the pack made up, and after deciding where you want to carry it on the bike, you can then wire it using the twin cable you bought. With tagged cells there's no problems in connecting to them, but there are things to note if using button end cells. You can solder directly to them without causing any damage and I've done so on very many occasions and never lost a cell. To do so, you must get your soldering iron very hot by resting it connected with the tip in free air so no heat is drained. Then tin the soldering iron and the wire end, afterwards soldering it to the positive button or negative end plate in a swift calm operation, blowing on the connection made to cool it immediately after. Heat and speed are the secret, the worst possible thing being low heat and a long time applying it to the cell.
Don't forget to observe the convention of using the black of your twin cable on the negative end plate and the red wire onto the positive end button. Now shorten the cable to the length required and connect the second XLR plug you bought to the other end of the cable, making sure the positive red wire connection corresponds to the red or noted positive pin connection on the added battery socket, ensuring the cells internally and externally are all in a series formation. The battery is now ready for it's first combined charge, so with the extra pack plugged into the additional socket, connect your charger to complete a charge.
Afterwards your controller will refuse the new setup, signalling voltage too high with 7 flashes on it's LED. The voltage will drop with time, but that could still take too long to be convenient, the controllers being variable in what they accept. My Torq one accepts up to 44.2 volts, the identical Quando one up to 43.8 volts, so from that I assume the specification is a 44 volt limit.
Charging either the usual battery or this radical one terminates with the battery hot and the voltage extremely high, that dropping rapidly as the battery cools, but still left too high for use. The answer to this inconvenience is a simple discharger. I've soldered four dropping resistors onto a three inch stub of wire, connected to another XLR plug. With this plugged into the charging socket for a short period after charging, a little is bled off the battery to remove that charge termination peak, bringing it to around the 44 volts mark.
To make a suitable discharger, buy from Maplin another XLR plug, and from four to ten 470 Ohm 7 Watt wirewound resistors, part code L 47 R. the more you have, the quicker the discharging. Bear in mind these get hot when planning the mounting. You can mount them on a piece of circuit or high temperature insulating board, on a high temperature terminal block or splayed in free air on the end of wires at least three inches long to keep heat away from the battery. In all cases wire them together side by side in parallel, stood away from any board used and with free air around each.
Then they are connected via wires to the outer connections of the XLR plug, ignoring the centre connector. When you plug it into the charging connection on the battery, each resistor will initially discharge at about the rate of 100 milliamps at 4.3 watts. Four of those resistors will bring the battery down to a usable voltage in about a half hour or so, but at first you will have to discharge in stages to see how long it takes to reach the "go" point. Once established, discharging for that period in future wil do the trick, for which you could use a "pinger" timer to remind you to unplug and not completely discharge your battery again.
I'm using four 220 Ohm 7 Watt resistors of the same type that I already had, and they are discharging at a rate of over 200 milliamps each at over 9 watts, 30% over their rating, so they warm the room nicely! It's still well within their safety margins though. If your discharging is too slow for you, just use more of those 470 Ohm resistors in parallel. Twice the number, half the time. Car buffs can use three 12 volt 22 watt stoplamp bulb filaments in series to roughly match the voltage, draining over 1.8 amps to bring the voltage down to acceptable in a very few minutes, or three 12 volt 55 watt headlight bulbs in series, draining over 4.5 amps to do the job in a few brief moments while you wait.
You don't lose lots of range with this discharging, it's just getting rid of a voltage peaking which occurs right at the end of charge before the charger switches off. To illustrate, if you fully charge your normal eZee battery and check it, you'll find about 43 volts. Ride your bike 100 yards/metres down the road and back, check it again and you'll get about 39 volts, 4 volts dropped in a few yards.
If I was a commuter doing the same daily run, I wouldn't bother with this discharging though. I'd just ascertain how long it took for the charger to reach the normal maximum voltage of about 44 volts and just use a pinger/alarm timer from then on to remind me to switch off at that set time
Your return for this additional trouble is a considerable boost to the hill climbing abilities of your Torq, and some increase in range as well, due to the better power to motor gearing ratio and lower battery stresses when under load. Cross country in hilly territory, your journey time will be cut and you'll be less tired at the end. More fun, less pain. On completion of this mod, stand by the bike, twitch the throttle, and the snatch forward will startle you, so hang on to the bars. You'll be left in no doubt about the power transformation. Please note that if you haven't full charged the added cells first, it will take a couple of charge and discharge cycles to normalise the charge levels and get the full benefit. If you go ahead, please post your impressions on the results in the Pedelecs Forum thread announcing this modification.
With the socket mounted, time for wiring. Ignore the centre contact on your additional socket, disconnect the positive wires from the top end tag of the cell termination and extend them as necessary using a short bit of the cable you bought to connect to one XLR connection. Note down which one carries this connection that was from the positive cell end, and preferably mark it on the case or socket with a red label or paint. Now take a short piece of your cable and connect the other XLR connection to the positive cell end tag. Securely insulate all the joins made with pvc tape or self amalgamating tape. While you are doing this soldering, take one of the two XLR plugs that you bought, open it and solder a jumper piece of the thick wire across the two outer connections. This is your shorting plug, which plugged into the extra socket which will enable you to use the bike with the battery as standard without the extra cells.
That's the battery modification complete, so carefully reassemble it. If you wish to do this job by stages, the battery can now be used meanwhile by employing the shorting plug for both use and while charging. Since the XLR socket used is the same as the one used for charging, you must take care never to put a plug into the wrong socket which would result in immediate damage. You may wish therefore to put a clear warning marking on the battery. If you have access to a an alternative plug and socket system that fits, that would be preferable, but they must have a minimum 15 Amp capability if the performance is not to be impaired.
The Battery Pack
Time to discuss cells. The capacity you buy will be determined by the battery age and the use it's received. Over the period of the first 100 charges of an NiMh battery, the capacity actually increases slightly, then starts to tail off over the rest of it's life. Therefore, if your battery has had less than roughly 180 charges, buy the same size cells as the original ones, 9 Ah or if they aren't available, 10 Ah. If over that point and up to two years old, buy a size down, 8 Ah. If your battery is over two years old, it's not really worth doing this modification. If in any doubt as to what size to choose, always select the larger possibility. These loose large capacity Nimh cells are available from a variety of online sources, and come in two types, tagged or conventional positive button end. The tagged cells are easier to use, but also tend to be more expensive. Some suppliers such as Batteryspace in the USA also supply made up three cell packs. Whilst undoubtedly convenient, I'm given to understand that there are question marks on the quality control exercised by that supplier, so there might be a risk of a poor cell or two in a pack from there. If you have a suitable single cell charger when using those, use it to pre-charge the three cells.
If using loose cells, you can make them up in whatever format you find convenient to carry on the bike, tagged cells allowing more flexibility here, mounting in a box, plastic plumbing tubing or just bound together. If using button end cells, the only practical way is to strap them very tightly end on in a column of three, positive end to negative end in series of course. They can then be bound in card and again mounted as wished, a section on plastic plumbing tube being very suitable. Under no circumstances use a battery holder of the type sold by Maplin. The cheaply formed wire connectors in those are inadequate for carrying 15 Amp currents.
With the pack made up, and after deciding where you want to carry it on the bike, you can then wire it using the twin cable you bought. With tagged cells there's no problems in connecting to them, but there are things to note if using button end cells. You can solder directly to them without causing any damage and I've done so on very many occasions and never lost a cell. To do so, you must get your soldering iron very hot by resting it connected with the tip in free air so no heat is drained. Then tin the soldering iron and the wire end, afterwards soldering it to the positive button or negative end plate in a swift calm operation, blowing on the connection made to cool it immediately after. Heat and speed are the secret, the worst possible thing being low heat and a long time applying it to the cell.
Don't forget to observe the convention of using the black of your twin cable on the negative end plate and the red wire onto the positive end button. Now shorten the cable to the length required and connect the second XLR plug you bought to the other end of the cable, making sure the positive red wire connection corresponds to the red or noted positive pin connection on the added battery socket, ensuring the cells internally and externally are all in a series formation. The battery is now ready for it's first combined charge, so with the extra pack plugged into the additional socket, connect your charger to complete a charge.
Afterwards your controller will refuse the new setup, signalling voltage too high with 7 flashes on it's LED. The voltage will drop with time, but that could still take too long to be convenient, the controllers being variable in what they accept. My Torq one accepts up to 44.2 volts, the identical Quando one up to 43.8 volts, so from that I assume the specification is a 44 volt limit.
Charging either the usual battery or this radical one terminates with the battery hot and the voltage extremely high, that dropping rapidly as the battery cools, but still left too high for use. The answer to this inconvenience is a simple discharger. I've soldered four dropping resistors onto a three inch stub of wire, connected to another XLR plug. With this plugged into the charging socket for a short period after charging, a little is bled off the battery to remove that charge termination peak, bringing it to around the 44 volts mark.
To make a suitable discharger, buy from Maplin another XLR plug, and from four to ten 470 Ohm 7 Watt wirewound resistors, part code L 47 R. the more you have, the quicker the discharging. Bear in mind these get hot when planning the mounting. You can mount them on a piece of circuit or high temperature insulating board, on a high temperature terminal block or splayed in free air on the end of wires at least three inches long to keep heat away from the battery. In all cases wire them together side by side in parallel, stood away from any board used and with free air around each.
Then they are connected via wires to the outer connections of the XLR plug, ignoring the centre connector. When you plug it into the charging connection on the battery, each resistor will initially discharge at about the rate of 100 milliamps at 4.3 watts. Four of those resistors will bring the battery down to a usable voltage in about a half hour or so, but at first you will have to discharge in stages to see how long it takes to reach the "go" point. Once established, discharging for that period in future wil do the trick, for which you could use a "pinger" timer to remind you to unplug and not completely discharge your battery again.
I'm using four 220 Ohm 7 Watt resistors of the same type that I already had, and they are discharging at a rate of over 200 milliamps each at over 9 watts, 30% over their rating, so they warm the room nicely! It's still well within their safety margins though. If your discharging is too slow for you, just use more of those 470 Ohm resistors in parallel. Twice the number, half the time. Car buffs can use three 12 volt 22 watt stoplamp bulb filaments in series to roughly match the voltage, draining over 1.8 amps to bring the voltage down to acceptable in a very few minutes, or three 12 volt 55 watt headlight bulbs in series, draining over 4.5 amps to do the job in a few brief moments while you wait.
You don't lose lots of range with this discharging, it's just getting rid of a voltage peaking which occurs right at the end of charge before the charger switches off. To illustrate, if you fully charge your normal eZee battery and check it, you'll find about 43 volts. Ride your bike 100 yards/metres down the road and back, check it again and you'll get about 39 volts, 4 volts dropped in a few yards.
If I was a commuter doing the same daily run, I wouldn't bother with this discharging though. I'd just ascertain how long it took for the charger to reach the normal maximum voltage of about 44 volts and just use a pinger/alarm timer from then on to remind me to switch off at that set time
Your return for this additional trouble is a considerable boost to the hill climbing abilities of your Torq, and some increase in range as well, due to the better power to motor gearing ratio and lower battery stresses when under load. Cross country in hilly territory, your journey time will be cut and you'll be less tired at the end. More fun, less pain. On completion of this mod, stand by the bike, twitch the throttle, and the snatch forward will startle you, so hang on to the bars. You'll be left in no doubt about the power transformation. Please note that if you haven't full charged the added cells first, it will take a couple of charge and discharge cycles to normalise the charge levels and get the full benefit. If you go ahead, please post your impressions on the results in the Pedelecs Forum thread announcing this modification.
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23.6.2007
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