Beginners Guide to Replacing Bad Cells
With spare cells becoming more easily available 2ndhand, I thought I would buy some and attempt to find and replace any bad cells on my Vectrix. Although my Vectrix meets my everyday needs of a 24 mile round trip commute, it does suffer from the red light coming on when the battery level is indicating 1/3 full. This can easily happen towards the end of my journey if it has been a windy day or particularly cold. So to this end, I have purchased a module of 8 spare cells on Ebay and will document the end to end process for a beginner.
There is a lot of valuable information that Mik posted in the handbook. Pretty much all you need. Do you have a lot of time on your hands. If mot, leave this for the winter time. If you do it right, your bike will be out of commission for at least 2-3 months. I did a rebuild of a battery. You need to test each bank down to the cell level. That's 102 cells. You need to charge, discharge and measure, charge again... Lots of time involved. In my case, I found not one or two but 20 cells that needed replacement. You will get the hang of replacing individual cells eventually but it is not easy. Do you have a CB-2 battery tester? Do you have a smart charger that can safely charge each block back up? If not, there is the real potential of making matters worse. On the bright side, you learn a lot about this bike in the process.
Best of luck, if you have specific questions that are not answered by Mik's excellent posts I am sure there will be plenty of help coming.
Dan, see my PM
Good is if you can post here video about Replacing Bad Cells!!!
Interestingly, I managed to use only one inrush current limit lamp (40w 240v) when re-initialising my bike. I left the positive terminal disconnected connected (supply to m/c) and then connected the Anderson (blue) connector. The lamp then went between battery +ve and the flying lead from the m/c. When it had gone out, it was just a case of keeping the lamp connected and fitting the M6 bolt though the m/c supply lead terminal and doing it up.
A point to note here that I know has been stressed before is that you can't take enough safety precautions with HVDC - I always work wearing arm length PVC gauntlets (gloves) and insulated tools where possible. Mik wrapped it up nicely with one of his post a while ago - if you're interested it was this post (#6) http://visforvoltage.org/forum/8918-new-battery-completely-discharged-vectrix-wont-give-any-sign-life
Further more, I now have a proper inrush current limiter, though it's wired really strangely and took a while to work out how to use it as it came with absolutely no instructions! Both methods work well and I'd suggest that the lamp method is considerably cheaper!
Easiest is to use piercing alligator clips. They go on each side of the battery connector piercing through the insulation of the flat cable. Check for continuity first before reconnecting.
In the words of 'Hitchhikers guide to the Galaxy' DON'T PANIC.
Disconnecting the battery is simple. Just pull the Anderson connectors apart and you are there.
Re-connecting is also quite easy.
When you re-install the batteries, you will have the plastic cover off the rear battery. This is necessary in order to make the connections.
With the rear battery in place, first of all connect the negative lead (the one on the right side when looking forward) then connect the Anderson connector. You are now left with the positive lead to connect.
Connect one wire of your current limiter (the thing everyone seems to call the 'inrush current limiter') to one of the cell interconnecting straps about three or four cells back from the positive battery terminal.
Connect the other end of the current limiter to the positive lead (the one you want to connect to the battery). The bulb (lamp) will light up and then dim and go out (keep/maintain the connection for a further five seconds to ensure a full charge on the capacitors). You can then safely disconnect the current limiter from the positive lead and then connect the lead to the battery and tighten up on the bolts.
The current limiter is used for charging up the capacitors in the motor control module. The capacitors, once they are charged via the current limiter, will hold sufficient charge for up to twenty seconds after the current limiter is disconnected for a safe re-connection to be made.
The real danger to life is in the battery voltage. The danger to all else is in the available current (remember that, at the battery, there is no fuse and the available current is Voltage Divided by the cell internal resistance. By calculation the available current during a short circuit is approximately 1000 (one thousand) amperes) Don't short circuit anything, and Don't get you fingers across the battery terminals.
Despite all of this danger, I don't use insulated tools and I don't wear any gloves. I am well aware of the potential hazards and I take extreme care, every single move I make is thought through first and then carried out CAREFULLY.
I am not suggesting that anyone else does things my way, but I prefer to work with full knowledge of the danger of the situation at hand and the equally full knowledge that it is me that gets to be dead if anything goes wrong (I also find that handling tools whilst wearing gloves is a hazard in itself).
The alternative way is to try to make everything fool-proof in order to prevent accidents. It is my experience that, when everything is (theoretically) fool-proof, people get a false sense of security and THAT IS WHEN THINGS CAN GO WRONG.
I have re-connected batteries a dozen times using the above method.
I do not trust my luck, instead, I plan every move and take extreme care.
(Doing his own thing and telling it like it is, as usual).