Battery Vehicle Society

Yesterday I collected the first Astra conversion from Dragon vehicles circa 2009. Dare I say it, the only Astra conversion? On test driving the vehicle the thing I noticed was the final drive is the noisiest I have ever heard, ICE noise will cover a lot but not this I imagine. The noise is mainly on the left side. It will need I gearbox from a scrappy I suppose. Its so bad the car does not coast very well.

The conversion cost 27k apparently on top of the 6k vehicle cost so potentially quite a mega vehicle. The battery is 48 off 200Ah Hi-Power, the old type, connected in pairs. If anybody can sell me some please say. The vehicle was maintained by college students in Scotland initially and I soon notice two battery cells disconnected and only single cells used in 2 places. This of course halves the useful capacity of the pack. The two dead cells had swollen considerably and pushed out the end of the rack. The end one being badly misshapen by the one next to it. For now I have restored double cells albeit with less pack voltage.

Trying to test the volt-drop of the cells was a failure with no drop detectable, It seems to me the zapi controller must limit the current if no motor rotation detected? Once I drove the car the bar graph, which is the only instrumentation available on the car, dropped off dramatically. I must get one of those nice dual displays with V, A and Ah.

Thank you to Jeremy and Mike for advice on batteries.

Rory

I know you should not reply to your own post but I will anyway.

Starting to look at Electrifit Zapi controllers and I see they may do a regenerative braking setup. I think this may be what I have got as there is a complicated array of 5 contactors which seems similar to the photos I have seen. If so it is very mild. I would prefer a brake activated setup. Does anyone know about these systems?

Today I suddenly lost a load of power when at a roundabout. Could hardly get going at all. Eventually revving the motor and using the clutch got me going. Not a battery issue as the bar graph was healthy.

It seems the builder did not follow the manufacturers requirement for clamping the cells between end plates. This has resulted in the demise of two cells which are distorted to hell.

Hi-Power Cells seem to suffer from high impedance and I today purchased a cheap battery tester from Machine mart which seems adequate to differentiate between good and bad cells, The addition of a digital display would help and I will probably do that. Certainly a lot quicker than using a capacity tester. Capacity can be revealed by measuring voltages with the pack fully discharged.

I am going to have to partly dismantle the Astra pack to test the cells as they are paired.

The plan of attack at this stage is to remove the front battery rack and weld in solid end plates to protect the cells from swelling. Then change the gearbox. Then reinstall battery rack. The controller tray will also have to come out for the gearbox change.

Rory

To test under load, jack up car and put on axle stands, with front wheels off the ground, the driver uses acceletor and brake to load the motor, and then see what the cells are reading with rotaing driven load. If needs be disconnect or jump the brake light switch, if that is used to control regen.

Grumpy-b

Ah so the regen could be controlled by the brake light switch. Seems a bit crude just to have one level of regen. Is this Zapi normal practice?

Rory

Some controllers use the brake pedal to initiate some of the regen, most new Hybrids dont use the throtle but are controlled by the brake pedal, and use the iniatial movement as the regen only going to actual brakes as pressure increases.
You can add extra regen control on the Curtis by the use of a pressure to voltage device, I like the outcome from this, as the harder you push the harder it regens.
But the point here is that if the brake pedal does have any regen control/ power take off then it doesnt help with testing under load. If you put your foot on the brake and the power drops off then you need to sort that first.
Regen or just power cut off, check out what it does.
Grumpy-b

Hi Rory

Replying to your PM, I have 6 spare 200Ah HiPower cells I could sell you if that is any use. I will send you an email.

Thanks to Tim I now have some cells to repair the Car. When I got home from Tim's house there was a replacement gearbox sat on a pallet so I had better get cracking. I suppose the huge torque that an electric motor can produce in first gear must have destroyed the final drive bearings.

Before that I think I will put the cells on charge although they seem to be happy.

Rory

Rory166 wrote:Thanks to Tim I now have some cells to repair the Car. When I got home from Tim's house there was a replacement gearbox sat on a pallet so I had better get cracking. I suppose the huge torque that an electric motor can produce in first gear must have destroyed the final drive bearings.

Before that I think I will put the cells on charge although they seem to be happy.

Rory

Hi Rory,

You'll probably find that you don't need first gear. You should be able to pull off in 2nd or 3rd.

I would check that the coupler looks in good order and is centered as this could be the reason for the gearbox failure.

What are you doing for balancing / BMS?

I would hate to see the cells get destroyed!

All the best,

Mike

Mike

Yes 1st gear is probably not needed. I think the final drive has failed rather than the input because one side is much noisier than the other. There is a top balancing BMS in the charger but nothing to monitor individual cells at the bottom. I will leave things as they are for the time being. Later I could add a Peter BMS perhaps.

Rory

Rory166 wrote:Mike

Yes 1st gear is probably not needed. I think the final drive has failed rather than the input because one side is much noisier than the other. There is a top balancing BMS in the charger but nothing to monitor individual cells at the bottom. I will leave things as they are for the time being. Later I could add a Peter BMS perhaps.

Rory

Sounds about right. thankfully the Vauxhall stuff is readily available.

On the BMS side of things, wait until the shunting has completed after installing the new cells to give them the best chance of survival. If you were to simply install them and then charge / drive they could be so far out of balance that something gets cooked...