Paul's 90Ah conversion

Hi Soyouz - Won't 7.6V x 19 = 144V be a bit much for the controller (and that's just the nominal voltage)? MW

Hi Martin,

No, the MC can handle 200V from what has been said on this forum, so no worry.

This looks promising! I already have a Nissan Leaf in the garage--it'd be nice to have the same batteries in the Vectrix as well. Please keep us posted.

Hello,

For sure Leaf cells are designed especially for VX. It is like the bike was built around !
I could put 19 modules easily.
63 Ah * 3,7 * 19 *2 = 8,8 kWh !! Without changing any parts of the bike and with very easy access to every cells.
I just begin this conversion. I hope to get the harness that come with.
Iwill keep you informed.

Hi Soyouz,

Great! Are you planning to use a BMS? If so, which?

Interestingly enough, EVTV have got hold of a load of the same cells from the Better Place 'fire sale' and are selling them very cheaply in their shop…

http://store.evtv.me/proddetail.php?prod=Betterplace

I might look to buy a couple of packs-worth for my kit-car EV if they have any left by the time I'm ready.

Good luck and as azvectrix says, keep us posted.

MW

Hello,

I rode my first km yesterday with my new bike converted with LEAF modules: 90 km with most of the time above 90 km/h !
Thanks to The Laird, I get a soft that charge the battery to 154V (real, not on dashboard), so ~80% of SOC. But as I plan not using a BMS (at least at the beginning), it is more safe to not go upper on high SOC.
And battery is 17 kg lighter than NiMh one !
Usable voltage is between 154V and 135V, so current is always low even during high power peak. Just electric brake is low when voltage is above 150V.

I really think that these modules were made for Vectrix conversion !

Hello,

I rode my first km yesterday with my new bike converted with LEAF modules: 90 km with most of the time above 90 km/h !
Thanks to The Laird, I get a soft that charge the battery to 154V (real, not on dashboard), so ~80% of SOC. But as I plan not using a BMS (at least at the beginning), it is more safe to not go upper on high SOC.
And battery is 17 kg lighter than NiMh one !
Usable voltage is between 154V and 135V, so current is always low even during high power peak. Just electric brake is low when voltage is above 150V.

I really think that these modules were made for Vectrix conversion !

That looks very neat. Congratulations, and enjoy your riding. Having range is a total game changer with this scooters.

Hi Soyouz,
Glad to see you have got your scooter going with better range and reliability. The Leaf cells are NMC cells which have longer range and are more reliable than an LiFePO4 conversion. Your 19 batteries or 38S setup is too high a voltage for the Vectrix motor controller. I know it has 200 volt capacitors and IGBT's but above 147 volts the controller shuts down regen braking in over voltage mode. Better to use 18 Leaf batteries. With 19 leaf batteries the low voltage limit of controller won't protect your batteries in run flat situation as 115 volts is too low for 38S setup. If your careful with charging and don't run flat, your batteries should last.
If the batteries haven't been used for some time I would manually balance them for the first 5 charges as the cells are reforming. After that NMC stay in balance and will only need checking occasionally.

Hi LithiumVectrix,

The most troublesome is the regenerative braking that shut down at high voltage. I am use to it now and it is a pity to come back to normal brake. I will consider your proposal. It is less range but less weight too...
And I didn't know about 115V MC protection, I ride with voltage indication so never at low SOC.

Hi LithiumVectrix,

The most troublesome is the regenerative braking that shut down at high voltage. I am use to it now and it is a pity to come back to normal brake. I will consider your proposal. It is less range but less weight too...
And I didn't know about 115V MC protection, I ride with voltage indication so never at low SOC.

Hi Soyouz,
This conversion looks really neat and tidy. Is it a straight 'battery swap' or are there any other changes needed to the bike ? Any chance you could give us lowly mortals a step by step guide of how you did it (with pictures) ? Thanks, Allan.

Hi group,
I have posted enough details about this conversion. I researched and developed my solution. I know it works. I guarantee my work. Members of this forum asked me for details about it.

I don't have a lot of knowledge, just enough to keep my electric scooter going and do some simple modifications to make it ride better. So forgive me if I ask this question about your system of Nimh cells in parallel with your 18650 cells. This is a concept that will somehow help all your cells (45 X 18650 paralleled) to self balance when connected in series only?
The way my limited knowledge sees it, 45 Lithium cells paralleled and 3 Nimh cells in series paralleled with the Lithium is a single cell, so everything will have, or will try to have the same voltage. Three Nimh is 3.6V and one 18650 is 4.2V, I just don't understand how paralleling these two chemistries can work.

I don't know any particulars, but you are comparing nominal NiMH voltage with fully charged LiCo. 3 fully charged NiMH cells would be over 4.2V, a LiCo cell is a nominal 3.7V.

Hi Soyouz,

How is the LEAF module conversion going?

Can you tell me which charger you have - the Runke or original ESD one?

What versions of firmware are the controller and charger running now?

Regards, Martin.

I don't know any particulars, but you are comparing nominal NiMH voltage with fully charged LiCo. 3 fully charged NiMH cells would be over 4.2V, a LiCo cell is a nominal 3.7V.

Silly me, you're totally right on that. So since all the cells are in parallel, they will all have the same voltage, if lico is at 3.8, the nimh will also be at 3.8. If the lico is at 4.2 then the nimh will be at 4.2.
I just don't understand the benefit of having these two chemistries together in parallel, a whole lot of cells in parallel is a single cell, and one cell doesn't have two different voltage. I can't wrap my brain around this. But there's many things in this world that I can't wrap my brain around and they still work :-D I just want to understand this better.

I agree - I have no idea how this works when they are both charged to the same end-voltage.

I agree - I have no idea how this works when they are both charged to the same end-voltage.

the lithium has self discharge so low as to be negligible

the nimh cells have some self discharge all the time, which rapidly increases when the nimh cells are hot, fully charged, or both

the nimh cells will hold the voltage of the LiCo cells below 4.2v when they are fully charged

Is it possible to simplify to the pack level, putting all the NiMH cells in one mini-pack paralleled with the entire Li-Co pack, or will that lead to too much imbalance on the cell level?

Is it possible to simplify to the pack level, putting all the NiMH cells in one mini-pack paralleled with the entire Li-Co pack, or will that lead to too much imbalance on the cell level?

the whole point of having the nimh cells there is to do balancing at the cell level

it's actually not a solution I recommend, (because it won't stop the charger from overcharging in a fault situation) I'm just explaining how it is supposed to work.

you just need a way to halt the charger if any cell group goes above 4.2v (for LiCo)

Hi Hempev,
The NiMh battery has a different charge characteristic than a Li-Ion battery. The nominal voltage of NiMh is 1.2 volts. The fully charged floating voltage is 1.41 volts. As a NiMh battery is charged above 1.41v it converts extra charge to heat and releases this from the battery. This is why the NiMh version of the Vectrix required cooling fans while charging. By combining 1 Li-Ion battery in parallel with 3 NiMh batteries in series you make a self balancing battery. This is the theory and now the practice. In a Vectrix you use a 35s battery Li-Ion not LiFePO4. Maximum charge voltage is 148 volts set by the Lairds 60AHLION03.hex firmware. When using this firmware the battery gauge work correctly and no other modifications are required. You never have sudden disappearing bars. Low voltage protection is provided by motor controller firmware MC1014b.hex. The scooter can be run down to limp home mode. With this battery setup and firmware limp mode is extended to 4 Km and then it will stop. Battery is protected from over discharge. To build one of these batteries you must use premium quality NiMH cells such as Sanyo HR-4/3AU industrial batteries.
http://www.master-instruments.com.au/cgi/ajax/get_file/55244/1

You can use any of the Li-Ion battery chemistries used in electric vehicles. NMC, LiCO, NCR or LiPo. LiFePO4 was designed as a battery for energy storage in stationery applications. None of the commercial electric car manufacturers have used this chemistry in a successful vehicle. The Li-Ion- NiMH hybrid battery achieves accurate cell balancing. Figures achieved are + or – 0.015 volts per Li-Ion block between 3.40 and 4.20 volts. This is better than any of the commercial BMS systems that I have researched. The 90 Amp/Hr Vectrix that this refers to is now 3 years old and has 34,600 Km on the odometer.
I have not built one of these hybrid batteries for 2 years now. My current builds have electronic balancing built into each battery block. This is lighter than using Ni-MH balancing.
http://www.evalbum.com/4802

Being poor at electronics and sloppy at fine soldering, the NiMH method looks simple and effective, but what kind of balancing have you chosen to replace it - one of your own design or another supplier?

If I were in need of the switchover to lithium, I would go with LiMn from the LEAF or similar EV as previously shown, but I still have enough effective range from the NiMH for now.

I have the same doubt of hempev.Wich electronic balancing module have you used on the 60Ah conversion.My other doubt is , if the samsung 18650 ICR1865022F/U can perfom like the panasonic cgr18650cg.

Tha last and not less important is , if all the problems with the motorcontroller , usually blown IGBT , can be avoided with proper refrigeration.

Thank you , and please forgive any silly or stupid question cause i'm still learning.

I have a stock of NOS NiCds - will these work in the same way as NiMH cells, or are their charge characteristics just too different?

Hi all,

Whilst searching for LEAF cells (in vain), I came across the new CALB CAM72F cells. Looking at the specification they have 121Wh/kg. Now, they aren't as energy dense as the LEAF cells but not too far off. They are 29mm wide so would come to 232mm in width with 8 cells. One could possibly get 5 columns worth (if one was able to request slightly narrower cells, say 28.8mm), equalling 40cells. Possibly another cell at the end of those columns. If 41 cells that would be 131.2V.
Is it feasible? Too low a voltage for a NIMH Vectrix? One could put some cells on a second layer perhaps?

I note that one can still get 24kWh of those Better Place cells, at $7000, but then there's the shipping to consider.

The NiMH batteries used in this battery have to be premium quality. They maintain the balance of the pack. Low leakage batteries with high quality seperators such as Sanyo Eneloop, Sanyo HR-4/3AU NiMH, Panasonic HHR-450A NiMH batteries.

The NiCds have lower leakage than NiMH, so the issue is less voltage drop-off than it is end-voltage and charge/discharge curve compatibility.

Hello,

@Martin :
The bike I converted is an early 2007 VX, so it is an ESD charger.
Thanks to that I asked The Laird for an adaptated soft for the 19 modules : charge until 156V = CP156, CC156. That allows the bike to charge at 80% (because the real voltage at battery is lower than 156V).
For a 18 modules conversion the 60Ah, 148V Li soft from The Laird would be OK.

I don't plan finally to use any BMS.
- For safety, I assume the risk (it is my choice, not the safer one), mostly because I limit charge to 80% SOC and also because Leaf module are intrinsically safe (not as good as LiFePO4 but OK)
- For balancing: As said before in this thread, I don't think electrons disappear, at least with very good manufactured cells (no internal short-circuit).
One the other side, there is something that unbalances the cells for sure : the BMS itself ! As it has to permanently measure the cell voltage, it takes some current on cells, like a little permanent short-circuit. Depending of the quality of BMS (and price then), it is mA or µA but it is a leakage current! So BMS has mostly to balance cells because it has unbalanced them...

Hi guys, I have some bad news about my Vectrix 90 Amp/Hr build. The scooter was in an accident when a car ran into the side of it. I was 110 km away delivering a client's battery. I was able to ride the scooter home but the chassis is bent. The left side is pushed in and it won't track straight. The scooter is a write off and I will use the batteries again. I will build another scooter but it might be a while as I have 2 more batteries to finish off for clients. They pay me and come first. I have a few new ideas that I want to try and will keep you informed.

Hi guys, I have some bad news about my Vectrix 90 Amp/Hr build. The scooter was in an accident when a car ran into the side of it. I was 110 km away delivering a client's battery. I was able to ride the scooter home but the chassis is bent. The left side is pushed in and it won't track straight. The scooter is a write off and I will use the batteries again. I will build another scooter but it might be a while as I have 2 more batteries to finish off for clients. They pay me and come first. I have a few new ideas that I want to try and will keep you informed.

That's rotten news, Paul. Glad you're ok.

Will you be dismantling for salvage? I could do with some body panels...