PHEV mod under way, Bristol, UK.

No, not yet. I've been so busy with the day job that I've not had five minutes to ring around the couple of leads I have for a second pack.

However, now I'm working in all the schools I'm doing this trimester I really do need to get the PHEV working. I'm looking at about 260 - 350 miles a week!!!

A friend is going to help with the new custom wing (fender) EV plug install next weekend, so I'll post photos as that happens. This weekend I need to take the current fender off and measure the space behind.

If the weather is okay this weekend I'm also going to try and switch the battery packs around so that the spare pack I have is used and charged up a bit.

But right now, I need to recover after a week of playing, teaching and driving!

​

 

Okay folks, so here's another update.

Last weekend we didn't manage to get around to getting the front fender off but we did manage to charge up that spare battery in my garage.

For those who are jumping in mid-thread, I purchased a spare battery pack from a scrapped Prius a month or more back. On getting it home and checking the voltage it showed a lowly 214Volts off load - a tad low.



Last week, when I measured it the battery had lost another few volts and was at 211V. That's too low for my liking, so I decided it needed to be charged.

I haven't got the fancy charger yet that I will use when the car is actually working as it's something I need to save for a few more months to buy. So the best solution to get the battery charged was to actually use the Prius to charge it. Otherwise, as previously hinted, I'd have a dead battery if it was allowed to self-discharge any further.

So, as it was one of our unusually dry Sundays a friend came over and helped me take the back end of Velma apart so we could at least partially charge the spare battery pack.

If you're going to take the Prius apart in any way, shape or form I highly recommend thehttp://www.amazon.com/dp/product/0837615534?tag=priuschatcom-20 a great guide. Without it we'd have been scratching our heads and not getting very far very fast. The Prius is really very easy to dismantle as most stuff either unbolts or unclips with no issue. However, you need to dismantle things in the right order.



We took the rear trim out (on both sides, although we could have left the side nearest the 12V battery in) and then removed the 40% split seat rear.

Lo and behold, tucked down behind the seat, right next to the HV orange cables, was this:



So that got moved pretty quickly. I'm not sure if it was a previous garage mechanic who left it there, the previous owner or perhaps even the factory. All I know is I'm glad it's not there any more!

With the 12V battery disconnected and the orange service plugs disconnected we were able to open up the car's original battery and remove the HV cables and ECU cables. Then, lying the spare battery on the back seat we were able to connect Velma up to it.

I feel obliged at this point to point out that the HIGH VOLTAGES THE PRIUS BATTERY PACK HAS CAN KILL YOU and that YOU SHOULD NOT DO THIS UNLESS YOU KNOW WHAT YOU ARE DOING. Of course, it also goes to mention that you should not follow what I've done as gospel, nor should you take it that I'm a leading authority on the subject. I'm not responsible for someone else frying themselves after reading this - nor PriusChat! Right, oh, and WEAR PROPER, HIGH-VOLTAGE-RATED LINEMAN'S GLOVES WHEN DEALING WITH THE HV BATTERY PACK OR HYBRID SYSTEM.

Now that's over and done I'll continue.

We double, triple and quadruple checked everything before we reconnected the 12V battery. I think if anyone is working on this part of the Prius the should never do it alone. Having someone else there who also understands exactly what is going on and the dangers involved helps to make sure that a mistake is not made. Once we were sure everything was okay we carefully reconnected the 12V auxilliary battery. With that done I rebooted Velma and waited. The CAN-View sprung into life and told me that the attached battery was at 211V, exactly as I'd expected. SOC was about 50%. Now here comes the nasty bit, as I know it goes against everything I ever do with the Prius: I forced the engine to run.

Putting the car into D and running the engine with the brake firmly on helped force-charge the battery. If anyone knows a better way of doing this I'd love to hear it. However, after a few minutes the battery reported an SOC of 83% and a Voltage of 250V. I then turned the car into EV mode and ran the AC to discharge the battery, giving it a full discharge/charge cycle. We kept our eye on the battery temperature too to make sure it didn't overheat.

Then, after another recharge cycle we turned off the car and disconnected the 12V battery, before donning our HV gloves again and reconnecting the original battery.

All went spendidly and the spare battery was put back in the garage with an off-load voltage of 232V.

Hopefully that will let the battery sit for another month or so, by which point I hope to have another battery (and more parts of the conversion) to properly start work on assembling the pack.

So, until the next installment!

Nikki.

 

Because when you're working on the Prius you should always make sure there's no chance you can accidentally switch the car on - or short out any 12V electrics!

There are circuits within the prius which are constantly live. It's never a good idea to work on any electric circuits with a risk that they could be live.

I did forget to mention though that after disconnecting the 12V battery you need to reinitialize the power window circuit when you reconnect it.

Details on how to do this are in the Bentley factory manual.

 

Hehehehehe.

Yes, I'm a professional oboist and teacher. I guess I'm a bit of a nutcase to be doing the conversion too eh?

I'm going down the PHEV diy route because I refuse to pay £14,000 for a commercial conversion. There's only one company in the UK doing it - and that's about the price. Plus I really want a more fuel efficient Prius.

I used to own a pure EV for two years. It was great never having to fill up - but sadly the range of the EV - 20-30 miles, wasn't enough for me to use when driving between schools for work. I couldn't afford two cars (nor did I have the space for both), so I ended up taking a backward step and getting Velma, my 04. My partner Kate has an 07, which we have had since new. It seemed logical to get a cheap 04 and convert it to PHEV to use for a few years until longer range EVs come onto the market.

So that's the story

Nikki.

 

Hi guys,

Yeah - regarding BMS. I'm a beta tester for the BMS + system. Norm isn't selling them commercially yet until he's got successful beta testers.

I've found another battery, advertised at £200 h taxes in my hometown of Norwich. As it's a 250 mile trip from where we live now I've got to wait until the school holidays in four weeks before I can go and pick it up.

Nikki.

 

It's one month on and I have had a lovely few days in Norfolk seeing my mother and picking up the second battery.

The Prius I rescued the second battery from was in a bad way. It was a '56 plate (that's a 2007 model) which had been in a garage which had caught fire. The car looked in a terrible way but luckily the guys at the breaker's yard had taken out the battery and stored it somewhere dry.




When I arrived at the yard I found that the battery was on a table inside with the top part of the case removed. Sadly no orange safety plug was in sight and as usual, the scrapyard didn't know anything about it. I ended up having to don a bright yellow high-visibility vest and walk around the yard to the sad Prius - now missing it's front end. (for some reason a guy in London had purchased the whole front end up to the A post....)

I had to dig around in the miscellaneous mechanical and trim parts in the trunk to find the plug but eventually dug it out! Wooo!

On returning to the battery I donned the appropriate safety gear and checked the voltage of the battery. An open cell voltage of 230V gave me enough confidence to stump up my money and head away with it.




It was rather funny at the yard though, as no-one there wants another Prius to break up. They didn't really understand how the Prius worked and were certainly rather wary of the Prius. When Kate pulled up her Prius so we could put the new battery in the back the yard guys were really shocked to hear the car move without the engine on.

Not only was the Prius strange to them they did have to suspend disbelief at a car full of women turn up, dig around in a scrapped Prius and don high-voltage lineman's gloves to check out a battery they knew nothing about.

Still, I think we taught them how to a) safely remove the battery in future and b) how the Prius worked.

I don't think they want another one to break up though as we've scared them with the HV warning!

I have another week off work ( or rather, I have about a week of having only a few students) so I hope to get some work done on the battery casing and housing.

A friend is helping me create a microcontroller to help operate the extra fans I'll need to cool the packs and back off current when charging if the temperature is too hot.

I should also be getting my BMS + this week as it's about ten days since it was Canada. All that's left on the parts side is for me to confirm the order on the Charger. I've settled on a Zivan NG3 charger, set for a maximum voltage charge of 238V (With a power cut-off as soon as that voltage is reached). The charge curve will be one appropriate to a NiMH pack - constant current in stage I, followed by a slight tapering off in stage II and then complete shutdown (no stage III). I've also decided on a PWM interface and remote status monitor.

Total cost of the charger will be £560 GBP.

My total costs thus far are:

CAN-View - £295 GBP
BMS Plus - £200 GBP
Battery 1 - £240 GBP
Battery 2 - £230 GBP
Charger - £560 GBP
Additional wing for charging socket - £20
Spare fuel filler mechanism to install on wing - Free with battery 1.

Total cost thus far: £1546 GBP!

Obviously I'm going to be spending extra for battery box materials plus some approrpiate wire and connectors for the actual pack wiring in.

I'll keep you all posted....

 

The orange HV safety plug actually breaks the HV pack in two, so removing it disconnects the pack completely.

Annoyingly the guys at the breaker's yard didn't know the importance of the breaker and assumed it was just a fuse. While there is a fuse hidden inside it's a device first to split the pack in two.

If the weather isn't too bad over the next few days I'm going to try to take one of the packs apart a bit to see how I can fit the batteries in the trunk.

Nikki.

 

Aaaaah - I think they have given you only the usual data then!

You're quite right - an NG3 in standard setup will kill a NiMH battery and in a worse-case, set fire to it. However, the UK agents for Zivan have worked with the Italian head office to develop a charger profile for NiMH batteries. Unlike the standard charger profile this one will cut off the voltage at an approrpiate level to prevent overcharging and doesn't have a 'gassing' phase to the charge cycle that the normal Zivan has. It is the charger's gassing phase which is most dangerous to NiMH batteries.

As for the temperature sensor - this is actually an accessory. I don't want or need one with mine. In fact I'm going to use a external temperature sensor and microcontroller arrangement to ensure that the Zivan does not charge at high current if the battery pack temperature is too high.

More on that to follow. I hope it makes sense!


Nikki.