Hill Climb Boost Battery for the your Torq

[flecc]

The T bike (Torq Radical) that I've just announced uses a technically simple NiMh battery modification that makes a substantial contribution to the greatly improved hill climbing. Much of the benefit will be given to any Torq using that battery, so I've posted details on how to achieve that in three different ways. This is not for the users of Li-ion batteries, strictly only for those with the NiMh battery.

If you're interested, read through the article first to understand what's involved. Here's the link.
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[coops]

Thank you for the very detailed instructions flecc, I will certainly be looking into the feasibility of doing this for the performance boost it gives the Torq.

I'll have to first locate a chippie a sufficient distance from me too, of course .

Stuart.

[HarryB]

Originally Posted by flecc

I'm not far too behind Peter, three eZee Li batteries to date, with two chargers.

But one is due for conversion to a T Radical NiMh type, to bring me to a pair of those.

The lithium chargers charge the NiMh batteries as well, but it's essential to stop the charge before it exceeds 42 volts, read when off charge.

Flecc,

A couple of questions. Are you still going to convert one of your lithium batteries to NiMH and is it possible to modify the lithium charger to cut off when they get to the right voltage? I wouldn't mind going over to NiMH when my battery finally dies however I have couple of chargers (one for work and one for home) and the cost of replacing them both would put me off.

[flecc]

Yes, converting the older Li-ion is my intention Harry, only delayed because the Q bike can still make efficient use of it even though it was previously dud in Quando and Torq. Come winter's colder weather though and it will be finished if not before, so that will be a good time. Also, the current silliness over the nickel "shortage" and NiMh cell prices will be over by then and larger cells might be here.

I doubt if it's possible to modify the charger, even though it's the same style from the same manufacturer. The problem is the Li-ion one cuts at a voltage rise signal, probably from the Li-ion battery's own electronics. NiMh chargers have cutout circuits operated by a voltage passed by a thermistor in the battery, that operating on the temperature rise just before the end of charging. That low voltage for the thermistor is generated by the NiMh charger, that circuit not part of the Li-ion charger's board.

I've also got two Li-ion chargers so I sympathise. If I do discover a way I'll definitely let you know though.

Ian has converted an eZee Li-ion to NiMh by the way.
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[HarryB]

Originally Posted by flecc

Ian has converted an eZee Li-ion to NiMh by the way.

I thought he already had gone down the NiMH route thus saving £100 and not having to replace batteries after 8 months. Do you know how he went about it, I have done a search but not come up with anything?

[flecc]

I only know he used the usual button end cells Harry, and bound them into the columns for the case. The trouble he had was that they are longer than the flat ended original so he had quite a lot of difficulty packing the longer columns into the case. I don't know what he did about thermistor or fuse.

I know what thermistor it should be though, it's a Semitec AT-4, part number: 103AT4 Shape 2. If not available, 103AT4 Shape 1 will also work. The main specification is R = 10k, B = 3435.

Semitec UK. Phone: 01606 871680, NTC Thermistors

If there's any problem, a wide tolerance replacement is a Murata component from Radiospares, part number 188-5256, R = 10k, B= 3380

Ian has just left on holiday before the weekend, but he'll be back in a couple of weeks so you could check for more details then.
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[flecc]

Originally Posted by HarryB

Flecc,

A couple of questions. Are you still going to convert one of your lithium batteries to NiMH and is it possible to modify the lithium charger to cut off when they get to the right voltage? I wouldn't mind going over to NiMH when my battery finally dies however I have couple of chargers (one for work and one for home) and the cost of replacing them both would put me off.

Harry, further reply. I've been trying out the Li-ion chargers on the Radical's NiMh battery, and both Li-ion chargers cut out at just over 42 volts, sensed by the voltage it seems. That's too low for the 33 cell Radical battery, but actually a good enough full charge level for the standard 30 cell NiMh battery, being just over 1.4 volts per cell.

If that also holds good for a standard eZee NiMh battery, and I think it will, they will be ok. I can't guarantee it of course, but perhaps another member who has both charger types and an NiMh battery would check by using the Li-ion on it and checking the battery voltage at end of charge. When Ian returns from holiday he might do that for you since he has the chargers and a standard NiMh battery.
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[Ian]

Originally Posted by HarryB

I thought he already had gone down the NiMH route thus saving £100 and not having to replace batteries after 8 months. Do you know how he went about it, I have done a search but not come up with anything?

Hi Harry,

I've got back and just caught up with this thread.

I've always favoured NiMh batteries and did buy an additional ezee one about 3 months ago, however I then bought a secondhand Sprint with a dud Li-Mg battery and as I had an almost complete set of NiMh D cells salvaged from an earlier bike it made sense to use them to re-cell it.

The cells I had were in a side by side arrangement with spot welded nickel strips joining them. Unfortunately the only way 30 cells would fit in the Ezee case was to arrange them in 6 columns of 5 cells which is the arrangement used in Ezees own NiMh batteries. After various experimental arrangements I came to the conclusion the only way they would fit would be to tear off the joining strips and rely on pressure for a good contact. I was 2 cells short of a complete set and the deficiency was made up with 2 pipped cells purchased on ebay. The battery has been working reliably for while now, its capacity is noticeably less, and the weight a few grams higher than the original Ezee batteries but I'm sure this due to the lower capacity, poorer quality salvaged cells used.

This is a diagram I made at the time, hope it helps. Note, it's not the same as the original Ezee build, they use what looks like shrink tube to hold the cells in columns, looking rather like sticks of dynamite, could explain why the bike is so fast.

Safety Note: It is very important that everything is well insulated with materials that can resist the temperatures reached, these cells can put out enough current to easily start a fire, particular care should be taken to avoid all possibility of a short between adjacent cell casings.

[Ian]

I Could have done with some of that extra climbing ability on the hill shown below. Funnily enough while walking the Torq up that quarter mile of 1 in 3 I met a postman coasting down on his heavyweight Royal Mail issue Pashley complete with panniers front and rear and a large handlebar bag. As the only other way out of the valley was up a similar hill on the other side I'm wondering how he did get out, perhaps the van collected him later.

[flecc]

Some of those Pashley riders get very strong Ian. I remember one day riding from the foot of local steep Corkscrew Hill at West Wickham having a Postie join from a side road riding a heavily loaded Pashley and cycling up there no trouble, sitting on the saddle. I only just managed to catch up with him riding the Lafree Twist electric bike.

Mind you, he was looking enviously at the Twist as we rode together along the flat at the top chatting about the bikes.
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