Charging a BEV with a Diversion Control system

[ClassicCrazy]

At work we had some fire alarm boxes that had a piezo type tone noise maker I think . It had a small hole in it where the sound comes out. During testing of the  system the noise could drive people who worked in the area nuts because it would be going off for whole day or more till completed. The simple solution I used to make it much quieter to silent  without harming or disconnecting anything was I would stuff a small foam earplug in the hole of the piezo. It would muffle the sound quite nicely . I didn't actually figure that out myself - I found an earplug stuffed into a remote board when I was checking it or wondering why you could barely hear it compared to the other ones . Have to remember to take those out after testing is done !

So if  you can get at the noise maker muffling it might be one possible solution .

I will be interested to hear  of your experiences with your new Bolt even beyond your charging if you have anything you would like to share about it.

Larry

[WillEert]

Hi Larry,

It appears Chevy designers are better than I gave them credit for. Chevy has a very good phone in help devoted to EV's but they could not help me with the chirping issue. There are a number of Bolt forums also:

Here is what I think is a good one:

http://www.mychevybolt.com/forum/viewtopic.php?f=11&t=6808&p=22664#p22664

I just had a new reply to chirp issue question. The answer is: turn it off using the car charge menu and explained in the manual. I read the manual but I missed that. Obviously I need to reread it

We have only put about 500Km on the car. I like it. It is quite intuitive to operate and I find it comfortable. It is slow to charge now as we only have the level 1 120V 12A EVSE charge plug. My level 2 is on the way...

We bought the car because of our belief that anything one can do to reduce your carbon footprint is a good thing. People do argue about how long it takes to go carbon neutral with an EV.

BEV economics:
Last year we spent $5500 on fuel ( we live 75K from the nearest town)
Bolt out the door $50K Canadian
if 75% of driving is now using BEV our fuel cost is reduced by $4125 (assuming gas remains the same).
Simple payback of car purchase = 50K/4125 = 12 years (A car that pays back?)
ROI = 8%

So if you have money in the bank or go borrow some you can buy a BEV and put some change in your pocket while saving the planet.

I like driving the Bolt. In my mispent youth I had an original 1968 Mini Cooper S. This car reminds of the "s" but on steroids. I am old but I can tell you the car will lay rubber if in sport mode at 30km/hr if you just floor it. It also handles very well. Like the Tesla the batteries are in the floor and it has low centre of gravity with the wheels at the corners. Fun. I think you would have to get engine sound recordings and play them loudly while you zoom around watching your battery level diminish quickly.

Will

[WillEert]

A lithium battery question:

Something I have come across a few times is that the battery bank will last longer if it not fully charged but left at 90% full or so. Some owners do this by using the Hilltop charging mode but they do not live on a hill. Evidently this turns the charge off before the car is full so that you can charge the batteries for free , if you live on hill, when you go out and regeneratively brake down the hill. I have seen 45Kw flowing to the batteries when we go down a hill or do regenerative braking.

I would like the battery pack to last as long as possible. Any thoughts on not filling the batteries up all the way? I wonder if you don't do full charging and the battery BMS top balances the cells you might actually do damage to the pack.

Will

[ClassicCrazy]

The only thing I can think of not filling the batteries all the way up is something like the bottom balancing I do on my set of lithiums.
The danger area of something going wrong with lithium batteries is at the top of their charge because you are relying on the BMS to carefully balance all the cells. The bottom balancing theory is that there isn't a lot of energy to be gained near the top and if you just stay away from those voltages you don't have to worry about balancing all the cells and associated risks of balancing circuitry failing and not doing the job. There is also talk about how they can get out of balance in capacity  with top charging .

I would think that the modern electronic balancing circuits they have these days must take everything into account though. Hopefully !

There is a website EVTV and he explains his theories and experiences on this method with electric cars.
http://evtv.me/2009/11/get-rid-of-those-shunt-balancing-circuits/

Thanks for your calculations - makes a lot of sense. I haven't seen any of the Bolts around here yet so will take a closer look when they show up .

Larry

[WillEert]

Hi Larry,

Thank You for the link regarding top balancing vs bottom balancing. I think I will put my "hilltop charge limiter" into operation. I can always turn it off for an individual charge if I feel I need the range.

Will