Cagiva motorcycle conversion

[MalcolmB]

This is a conversion of a 125cc Cagiva Planet that I finished a couple of months ago. It mostly uses off-the-shelf components:
15 hp Briggs & Stratton permanent magnet Etek motor
72V/450A Alltrax controller
Five 12V 26Ah sealed lead acid Enersys batteries
Albright contactor
Direct chain drive with 5.5:1 reduction
Five on-board 3A/12V 'smart chargers'

Weight 130 kg
Top speed on the flat 55 mph
Max. range 15 miles

I did this mostly for fun and to get some experience for a 'proper' conversion in the future. If I had to start again I'd definitely look for a lighter donor bike and seriously consider lithium ion, but it's been a great learning experience and I get a lot of smiles out of it!

[aminorjourney]

Brilliant!

Can we put this up in the "Members vehicles" section of the BVS website (http://www.batteryvehiclesociety.org.uk ... page_id=17 ) ?

[qdos]

Better still can you write about it and send it for the next issue of the Mag!

[MalcolmB]

Thanks for the compliment. Loved the video of the Fiat 500 on your website Nikki. I want one!
Yes, I'd be pleased to write something for the mag. How many words and who should I send it to?

[Fufunka]

I gather that's the same project/machine as the one posted at the world's ev album here:
http://www.austinev.org/evalbum/1161

I'm wondering about the 12V@3A CTEK-3600 chargers, rumor has it that they are the best option for the Pb batteries out there. Few months ago the supermarket chain Lidl was selling them in France, Germany, Czech and perhaps other countries as rebranded "Tronik T4X" just for fraction of the CTEK price. This was however only time limited offer..

It appeared at the Philippe's french EV forum in e-scooter installation:
http://vehiculeselectriques.free.fr/Forum/viewtopic.php?t=871&postdays=0&postorder=asc&highlight=ctek&start=30

In particular how practical is that desulphation phase of the algorithm is it really working so good? Thanks

PS Malcom would you please briefly describe the process how to make this particular conversion street legal? The Alltrax controller has got the CE (EMC) electronics appliance certificate for the EU. But what about the motor wasn't this ETEK only offered on the american market?

[EVguru]

There are a few issues with these chargers.

First of all, the charge current is rather low. Hawker actually specify a MINIMUM charge current (they specify it by power) for the Genesis series and I've found Optimas give better capacity when charged at higher current. It seems that higher currents cause the plate structure to become more porous and also stronger. They also need less equalisation when charged at high currents (1C or higher).

The charge is only 14.7 volt, which is Ok, but you should do an equalise charge occasionally. Even though you have a charger per battery, you still need to balance the individual cells with a controlled overcharge. Leaving the battery at 14.7 volt for 24-48 hours would do the job, but usually an overcharge at a fixed current for a specified time is specified. For the Optima (55 Ah) it's 2 amps for 1 hour with no voltage limit. John Olson, the Optima electrochemist told me to not exceed 17.5 volt during equalise and Hawker specifies 16.5 volt. There are various ways of determining if you need to equalise, like Ah throughput, end of discharge voltage difference and depth of discharge on the last cycle.

Sulphation occours EVERY time you discharge and is reversed by charging. HARD sulphation caused by overdischarging or leaving a dischaged battery to sit fot too long can also be reversed by charging, but can take a VERY long time (days or even weeks). Some of the pulse charging techniques do work and are faster, but many do not.

[MalcolmB]

Hi Fufunka
Yes, my bike is also listed on the Austin EV photo album – it's a great site for gathering ideas and I naturally couldn't resist posting photos of my own machine as soon as I'd finished it.

Because of all the rain we've had here I've only managed to put 500 miles on the bike so far, so I can't really say whether the desulphation action of the CTEK chargers actually works yet, but that was one of the features that made me buy the charger. I respect Swedish engineering and the chargers had a good reputation. If the Tronic T4 chargers really are rebranded CTEKs then that would make them a real bargain.

Getting the conversion on the road was surprisingly easy. First I notified the DVLA of the change in fuel type. Then I found an insurance broker (Carole Nash) who was willing to insure the bike at the same rate as the original petrol-engined version. The insurers did ask for a pdf copy of the Etek manual so they could check that the power output of the motor didn't exceed the original petrol engine. I took the bike for an MOT test, which it passed easily. Finally, I went along to the local DVLA office and asked for a new tax disc, which they gave me without any questions, free of charge A couple of weeks later I got a new V5 certificate back from the DVLA with the fuel classification altered to "Electric".

You're right about the motor only being offered to the US market and that was a concern of mine, but the issue never arose and I chose not to dig too deeply. Is it something I should be more concerned about?

Do you have plans to do a conversion yourself?

[MalcolmB]

Which alternative charger would you suggest for onboard use, Paul? Can you recommend a charger for fast charging and equalizing at home?

[EVguru]

You really can'y beat the Zivan NGx series for value for money http://www.zivanusa.com.

I've got room for an NG3 under the tank cover on my bike, but there's also a smaller NG1 model.

The real problem comes from the extreme inflexability of the charger. Despite being microprocessor controlled, it's not actually programmable except by the factory. The actual power stage is good, quite robust and simple to fix.

I'd go with a temperature compensated IUo curve (constant current, constant voltage, float) and do the equalise occasionally with an offboard charger. You can get the charger with an IUI (equalising) profile, but it will blindly do that every time wether you need it or not and prematurely age the batteries. In theory you can have both profiles and swutch between them with an internal link. However, bring that link out to an external switch voids the warantee. In any case I'd only ever run the charger on a time switch to limit the possible charge time.

The equalise charger can be very simple. A lightbulb can be used to act as a crude constant current regulator. You just wire a suitable wattage bulb (or two, or more) in series with the batteries and connect them to a high enough voltage source (a variac and rectifier for example), Over about a 4:1 change in voltage a lighbulb will maintain the current over a 2:1 range. Select the bulb wattage to give the right current and put the charger on a timer again.

[MalcolmB]

Many thanks for the advice Paul, I'll take a closer look at the Zivans. It is a shame about the lack of programmability though. Ideally I'd like to buy components that I can still use if I make adaptations, or re-use on other projects further down the line.