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Ian's hit the nail on the head.

It's been discussed a lot on here, and would probably save people a lot of grief with out of balance packs which end up being removed/replaced/reconditioned.

I looked at getting something suitable made and did get a quote a year or so back which was about $100 for a 180v DC 250ma CC/CV charger with universal AC 90-250v input.

Because of the high voltage dangerous output we can't just throw something together and hope for the best, we need to decide on a suitable spec and a safe connector which can be easily obtained and fitted by owners to their vehicle.

The actual connection to the pack is straightforward but access is difficult and people could be injured/killed if they are not familiar with high voltages etc.

I didn't get time to follow it up any further.

IMO we could, and in fact should get something made for our mutual benefit.

So if someone want to get some quotes for a PSU brick with the above specs be my guest.

Peter
 

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Hi Peter,

I for one, would be interested in purchasing such a charger. While my battery warranty in still in effect for another year or so, one of my main concerns with any hybrid is the battery pack.

I have followed many discussions on IC about this topic, with much interest. I would like the charger to automatically either drop charge rate when 'full' or shut off completely, if at all possible.

Look forward to seeing how this turns out.

Jim.
 

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Everyone should keep in mind that charging the batteries to full repeatedly will shorten their lives, and is not going to be all that beneficial.

Almost all of the battery problems that I've seen could have been avoided if there was a way to fully charge the pack. P1447 errors are almost exclusively caused by degraded cells (memory effect) that could have been eliminated with occasional charging to full. But not every day. Perhaps once every couple of months.

The lack of charging does not cause the problems. Individual cells out of spec (and cell wear) causes it, but cycling the battery or at least fully charging it would keep these cells in line and not allow them to degrade other cells in the pack.

As an analogy, think of it as changing your oil frequently to cover up an oil consumption problem. If you burned a quart of oil every 5000 miles, and you changed your oil every 3000 instead of 7500, you'd very effectively mask the problem. It wouldn't matter that you were burning the oil.

Here, it wouldn't matter that the cells were trying to get out of balance if you could force them back into spec temporarily by charging the pack.
 

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Well, I am leaning towards disagreeing with you on that. I have been plugin charging about 5 days a week for about a year now and haven't seen a noticeable difference in capacity.

After the weather finally gets better (spring-like) I will do an EV discharge run and see what the range is compared to last year. I'm not too enthused atm at removing the packs and doing full capacity tests, so that will have to do for now :)

Btw, for those who don't know I use a simple current limited charger that starts at ~600mA for two packs. Starting charge wattage is at ~130 watts and end charge is around ~70 watts after 12 - 14 hours. A usual charge takes about 1.5 - 1.8 kW/hrs. Since this is essentially a dumb charger I rely on the end charge being so weak as to not cause damage. It hasn't been an issue at all in the winter, but I do run the pack fans in the summer and have to remember to unplug the car or the packs do heat up into the low 120F range. This is due to charge + car interior temp due to the sun.
 

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I am not advocating a plug in charge every day, although as UH points out it may not be that detrimental. I'm proposing a charger used perhaps up to a maximum of once a week to reduce balancing issues in ageing packs. It could save everyone quite a bit and avoid pulling packs for a full rebuild/recon when it's not necessary.
 

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Well, I am leaning towards disagreeing with you on that. I have been plugin charging about 5 days a week for about a year now and haven't seen a noticeable difference in capacity.
I'm only referring to the rated lifespan in cycles. The Insight doesn't cycle the battery very far. You are half-cycling it daily. I don't know how much you are reducing the life of the cells, but you are reducing them.

How much are you actually saving by topping up the battery? Assuming a half charge to begin with on average, you are replacing, what, 3 mpg over a 10 mile stretch? Let's make it 15 miles because you are topping to 100% (above the Insight's capabilities).

I'm not saying this is not good to do, just that it isn't a huge $$$ savings. In a car with a large battery pack (Peter?), it's more advantageous.

I'm all for topping up your battery monthly or maybe even semi-monthly, but nightly will not benefit the pack and in my opinion will shorten its' life overall.

A charger like this would be advantageous for storage of the cars, though, and I might implement something like it to keep my "ready to go" exchange packs up to snuff...
 

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With my 40ah lithium pack I don't have a high self discharge issue.

Lithium cells are much better than nimh in this respect prob <2% a month.

Nimh self discharge especially the ones in our beloved Insight varies between cells which causes us the imbalance problems as they age, and it's very high prob in order of 10% or more a week.

I charge like an EV every day, and just replace power used during day. My cells if only partially cycled may last 5-10 years and many 1000's of cycles.
 

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I charge like an EV every day, and just replace power used during day. My cells if only partially cycled may last 5-10 years and many 1000's of cycles.
But "last" does not mean "stay in prime condition. The performance will degrade far sooner than that.

It's beginning to look like the average lifespan of a pack is about 7 years before it gets so bad that the car gives up. I expect that after a thorough reconditioning (and replacement of marginal and bad cells) that the battery would have an average lifespan of 5 years under the same conditions as original. I think with monthly top-ups we could easily extend the life to 12 years (between rebuilds). This exceeds your 5-10 years, which is what I mean by shortening the lifespan. Even the process of reconditioning the sticks shortens their life, but since it extends their usable life, it is worth doing.

Of course, if everyone topped up their packs, I'd be out of business. :D
 

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That's the plan Ron, extend the time between re-builds.

No point whatsoever you or I replacing, cycling or re-building packs if a simple monthly top up will get them back into balance and performing well enough to prevent error codes or poor IMA performance upsetting the average owner.

No one knows how long my Lithium cells will last in this application. We shall see in due course.
 

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I'm only referring to the rated lifespan in cycles. The Insight doesn't cycle the battery very far. You are half-cycling it daily. I don't know how much you are reducing the life of the cells, but you are reducing them.

How much are you actually saving by topping up the battery? Assuming a half charge to begin with on average, you are replacing, what, 3 mpg over a 10 mile stretch? Let's make it 15 miles because you are topping to 100% (above the Insight's capabilities).

I'm not saying this is not good to do, just that it isn't a huge $$$ savings. In a car with a large battery pack (Peter?), it's more advantageous.

I'm all for topping up your battery monthly or maybe even semi-monthly, but nightly will not benefit the pack and in my opinion will shorten its' life overall.

A charger like this would be advantageous for storage of the cars, though, and I might implement something like it to keep my "ready to go" exchange packs up to snuff...
Actually I am up 25 - 30 mpg for in town commuting, and up 5 - 10 mpg on long distance. Even more if I am driving mountains. In town is where charging comes into play. I have seen as high as 135 mpg in stop and go for a 10 mile trip, average is closer to 85.
 

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Actually I am up 25 - 30 mpg for in town commuting, and up 5 - 10 mpg on long distance. Even more if I am driving mountains. In town is where charging comes into play. I have seen as high as 135 mpg in stop and go for a 10 mile trip, average is closer to 85.
??? - It only takes about 10 minutes at a cost of maybe 3 mpg highway to charge the battery from half to full. (I'm estimating 15 minutes to a true full.) How does starting with an overstuffed battery give you 30 mpg more? Or is your in-town commuting day less than 10 miles?
 

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No point whatsoever you or I replacing, cycling or re-building packs if a simple monthly top up will get them back into balance and performing well enough to prevent error codes or poor IMA performance upsetting the average owner.
I don't think you could get them back into balance, but rather you can keep them from going out of balance. Once the pack goes out of balance some of the cells will take a hit and drop in capacity. It takes some deep cycles to bring back those cells. You still won't have a way to discharge the pack, so I doubt you could get them back up.

It wouldn't fix the problem, but it would stop the problem from occurring in the first place.
 

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And as Peter noted several posts ago, my intent in using a trickle charger is to keep the cells 'topped off' on a quarterly schedule, or even monthly, just to maintain the pack.

I had no intention of running the charger nightly, although it would be tempting to use more of the IMA battery during my commute to work, and then replenish at night when needed.

So I'm still interested in someone designing a safe 'charger' that stays with the car and I plug it in to 120VAC at night or weekends. If instructed clearly, I would love to install it myself, using the normal safety precautions.

Jim.
 

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??? - It only takes about 10 minutes at a cost of maybe 3 mpg highway to charge the battery from half to full. (I'm estimating 15 minutes to a true full.) How does starting with an overstuffed battery give you 30 mpg more? Or is your in-town commuting day less than 10 miles?
I'm saying that I can do 135mpg easily including stop and go within a 10 - 12 mile window .... then the batteries are dead (to the car). And yes, I drive about 10 - 12 miles a day average. That is of course under prime conditions Like a trip to the other side of town then back including stop lights. My overall average is actually closer to 85 mpg in town because of warmups, shorter drives, unplanned drives, etc. I live 2 miles from work, and usually make two trips there a day as I go home for lunch, plus add in daily errands. It sucks that living so close to work actually costs me mpgs :)

Before plugin charging my in town average was closer to 55 mpg. Also, on the highway it takes me approximately 30 - 45 minutes to fully charge both packs from empty to 100% according to the car, that is charging at ~12 amps or 1 mima led. The mpg hit is actually 10 - 15 mpg for me when charging and I can see this by going in and out of mima mode 1. For this reason I only use battery on the highway for accelerating or going up hills / passes. What I save on those hills and passes bumps my overall highway mileage up by 5 - 10 mpg.

Am I saving much at current gas prices, no, but I am saving a little. When I first got everything up and running I did a comparison to see if my 10 cents charges were helping and the conclusion was yes. With gas at $2 / gallon that number is lower, but still positive.
 

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I charge nightly due to mima, it is all Mikes fault!!! :) The first thing after the mima install (and I also mentioned this to Mike) was that the car needed more battery capacity with mima. I added battery capacity and the logical next step was to charge. Without charging I lost as much mpg as I gained from tapping a full pack then recharging with gas.

A little dirty math to see efficiency of recharging with gas vs electricity:

Full charge on highway for two packs ...... lets say 35 minutes at a 10 mpg hit @ $2.00/gallon

Lets say 60 mph to make it easy so we travel 35 miles.
I just lost 10 mpg (low estimate) over those 35 miles (low estimate), so instead of 80 mpg I got 70 mpg.

for 80 mpg I used .43 gallons = $.87
for 70 mpg I used .5 gallons = $1.00

This is a prime condition as we are maintaining speed. Consider that in town stop and go while recharging incurs even a bigger hit on efficiency and you can see how plugin charging more than offsets gas recharging.

This gives us a comparison of how much $ in gas charges the packs vs how much electricity. Rates here are about 6.5 cents a kW ... and I use about 10 cents a night. As the dirty math shows we are just past the break even point, but that number doubles with gas at the prices we had last summer.

/ramble off .....
 

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And yes, I drive about 10 - 12 miles a day average.
When you have such a small distance it skews the results. I'd say the typical person here won't come close to your results.

You are a prime candidate for a Chevy Volt when it comes out. If you grid charge every night and keep your daily travel below 40 miles, the engine will never even start. Then you'll have to convert kilowatt hours to gallons to calculate your MPG.
 

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When you have such a small distance it skews the results. I'd say the typical person here won't come close to your results.

You are a prime candidate for a Chevy Volt when it comes out. If you grid charge every night and keep your daily travel below 40 miles, the engine will never even start. Then you'll have to convert kilowatt hours to gallons to calculate your MPG.
Not at $40K, I would do my own EV conversion first or do a PHEV conversion to a Prius. Phevs are definitely skewed based upon battery capacity though more seems to be better :)
 

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When you have such a small distance it skews the results. I'd say the typical person here won't come close to your results.

You are a prime candidate for a Chevy Volt when it comes out. If you grid charge every night and keep your daily travel below 40 miles, the engine will never even start. Then you'll have to convert kilowatt hours to gallons to calculate your MPG.
He is a good candidate for any PHEV... like 90+% of the rest of the public.

The plug in charging will offset some gasoline that the car will not have to generate when it then goes to use assist later ... exactly how much is just another exercise of tiny details... and specific to a given situation.
 
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