[pm_dawn]

Hi !

I recently ordered a PFC1500 charger direct from factory.
We agreed on the settings after a couple of emails back and forth.
I have a 25cell pack of Sinopoly 100ah cells that I want to charge and discharge without BMS. I bottom balanced the pack to be safe at bottom and figured out that an ending current of 5A would charge the pack in a good way.
(This was done by charging with a non terminating charger and watching individual cell voltages in the end of the charge.)

I specified the charger to 85,2v and 5A ending current.

The vehicle had been using a bmsbattery 2000w charger that did not terminate the charge. So we were using a timer to charge the vehicle up to now.

I received the charger and installed it. Hoping that it would terminate the charge at 5A.
The charger hit the target voltage really nice. BUT it did not terminate at 5A.
It continued well under 1A. When the current was down to 0,8A I had one cell go above 3,95v and terminated the charge manually.

The factory has not been keen on reprogramming the charger to the specs we originally agreed on. They want me to add battery protection circuits.


Because of this I would WARN others to buy directly from TCCH since they do not deliver what has been specified in the invoice. And also they do not seem willing to sort their mess out. It has now been 10 days without any mail from them. I have in this period sent them a couple of emails trying to get a solution to my problem. I would urge others to watch out when doing business with these guys/girls. And to really test that the charger that you have received actually does what it is supposed to do.


Best Regards
/Per Eklund


Here is part of the conversation with the sales person.

--------------------------------------------------------------
On 15 aug 2013 07:59 "export2" <removed> wrote:


Dear Per

Thank you so much for your patience.

We got an answer from our chief engineer who is the key person who
developed the charger.

He confirmed that, to all Lithium battery charger, the float current is
necessary.

We wish you have a happy day~

Nancy Loo



Online Skype: nancyloolooMP:+86-136 666 70413

TCcharger- Tiecheng Info & Tech http://www.tccharger.com/


From:"ME"<[email protected]>Date:2013-08-12 00:36Cc:


Hi Nancy !

The Batteries are SinoPoly 100ah

I have been using LiFePo4 cells in cars for over 4 years.

I know what can be done with them.

This is the first time I have bought a TCCharger. I have heard that they
are very reliable and do a good job at hitting target voltage for the CV
phase of the charge.


If I would have wanted the charger to do a very low endingcurrent I
would have ordered that.

I have been using BMS on cars, and I have done cars without.

On this car I have a good matched battery pack that has been bottom
balanced for safety when driving. BUT I need the ending current to be
what I ORDERED !!!!!

I know you are quite active on the DIY forum
http://www.diyelectriccar.com http://www.diyelectriccar.com/.

I strongly urge you to reconsider your efforts to get this charger
reprogrammed.


I SPECIFIED 5A ending current for the charger.

WE agreed on that.

If I had know that the Charger you sent me would do this low ending
current I would NEVER had ordered it.


NOW give me a solution for this problem.

And the solution is NOT to PUT a BMS on the battery.

The soultion is to reprogram the charger to STOP CHARGING at 5A.

Send me a new firmware for the charger and a description on how to
reprogram it, OR

pay the shipping to return the charger to you for reprogramming, OR

Return the Money for the charger, and I will return the charger.


I look forward to your swift effort in solving this problem.


Best Regards

/Per


On 10 aug 2013 09:40 "export2" <removed> wrote:

>
> Dear Per
>
> Could you let us know the manufacturer of your battery?
>
> Can you please check with your battery supplier if it is better to use
> Battery Protection Board for Lithium battery?
>
> Thank you.
>
> Nancy Loo
>
>
>
> Online Skype: nancyloolooMP:+86-136 666 70413
>
> TCcharger- Tiecheng Info & Tech http://www.tccharger.com/
>
>
> From:"me"
> <[email protected]>Date:2013-08-09 17:38Cc:
>
> Hi !
>
> You cannot force me to use a battery protection board.
>
> I know what I am doing.
>
> These batteries does not need to be balanced more then once a year.
>
> That I do manually.
>
> Fact still remains.
>
> The charger you sent is not programmed according to the SPECIFICATIONS
> that we agreed on.
>
> If you do not find a way for me to get the charge reprogrammed I will
> have to urge you on a refund of the charger and a return.
>
> Best regards
>
> /Per
>
>
> On 9 aug 2013 10:58 "export2" <removed> wrote:
>
> >
> > Dear Per
> >
> >
> > Thank you for your quick response.
> >
> > As per our experience with different Lithium battery manufaturers,
> > they
> > all recommand to use battery protection board.
> >
> > Otherwise, the cell balance problem will become more serious. Even
> > the
> > charger has setup to 5A ending current, it can't solve the balance
> > problem.
> >
> > Please kindly understand. It is better to use Battery protection
> > board.
> >
> >
> > Thank you again.
> >
> > Nancy Loo
> >
> > Online Skype: nancyloolooMP:+86-136 666 70413
> >
> > TCcharger- Tiecheng Info & Tech http://www.tccharger.com/
> >
> >
> > From:"me"
> > <[email protected]>Date:2013-08-09 16:47Cc:
> >
> >
> > Hi !
> >
> >
> > LiFePo4 batteries will work very good even without protection boards
> > if
> > you set up the charger correctly. There is no "MUST" for having a
> > battery protection.
> >
> > I'm not going to add a lot of cell level protection to this pack
> > just
> > because you sent me a charger that has not been programmed to my
> > specifications.
> >
> > This problem is not a something that has to be adressed by a
> > protection
> > board.
> >
> > This is a pure charger problem.
> >
> > I ordered a charger that would stop charging when it had come down
> > to 5A of current.
> >
> > That is NOT what I got.
> >
> > So I restate my question from the last mail:
> >
> >
> > HOW DO WE RESOLVE THIS PROBLEM?
> >
> >
> > Best Regards
> >
> > /Per



On 9 aug 2013 10:28 "export2" <removed> wrote:


Dear Per


As checked with our engineer, using a battery protection board for
Lithium battery is a must.

The battery protection board can shut off charging if any
cell goes up to 3.65V.


Nancy Loo


Online Skype: removed

TCcharger- Tiecheng Info & Tech http://www.tccharger.com/


From:"Me"
<[email protected]>Date:2013-08-09 16:12Cc:


Hi Nancy

The Charger did NOT stop charging at 5A.

It continued under 1A.

The lowest current value I read was 0,8A before I terminated the
charge manually.


I do not use any battery protection boards in this setup.

That is why I was very picky about the ending current of the
charger.

Can you please provide a full charge profile description of the
charger you sent me.


The CHARGER IS NOT STOPPING CHARGING at 5A current.

So the product you sent me is not what I ordered.

How do we resolve that ?


Best REgards

/Per


On 9 aug 2013 09:05 "export2" <removed> wrote:


Dear Per

Thank you for your feedback.

The charger is OK.

The charger did stop charging at 5A. Only after a while, the LED
changed from Yellow to Green.


"I had one cell in the pack go to 3,96v.That is not good, If the
charger had stopped at 5A as I ordered the cell would not have gone
above 3,6v which I consider safe."
It is nothing to do with the charger.
It's your battery protection board's work. Your battery protection board
can send a shut off signal if the battery go up to 3.65V.


Nancy Loo


Online Skype: removed

TCcharger- Tiecheng Info & Tech http://www.tccharger.com/


From:"ME"
<[email protected]>Date:2013-08-09 13:55Cc:


Hi !


I would say the contrary.

So this means that what you call "ending current" is only when
the led changes from yellow to green.

That is not what I wanted !


I NEED the charger to stop charging at 5A 85,2v

That is why I was very specific about that.


I had one cell in the pack go to 3,96v.

That is not good, If the charger had stopped at 5A as I ordered the
cell would not have gone above 3,6v which I consider safe.


I need to resolve this in some way.


I have sent a skype request to you so that we can talk.


Best Regards

/Per Eklund


On 9 aug 2013 04:06 "export2" <removed> wrote:


Dear Per



Thank you for asking.


It's not a problem as you thought.

Actually, the ending current is 5A. The charger turns off at
5A. When it reaches 5A, the current will reduce progressively and
meanwhile
after a while the light turns green. At the time you measure the
charger, the current was reduced to 1A.

It's no damage to the battery pack.


Nancy Loo


Online Skype: removed

TCcharger- Tiecheng Info & Tech http://www.tccharger.com/


From:"me"
<[email protected]>Date:2013-08-08 12:15Cc:


Hi Nancy!


The charger has now been installed.

But it does not work as ordered.


The charger does not turn off as current falls under 5A as I
ordered.

I watched the charger go on well under 1A !!!!!!

That is not good for the battery pack.

How do we resolve this problem.

Best regards

/Per Eklund

 

[Siwastaja]

Well, the actual problem here is that the industry standard in using li-ion cells is to use a BMS. (Like it or not.)

While a no-BMS approach is a known kludge that has worked well for many people in many situations, it is still a "non-standard" way to do things, and you should expect problems in communication with experts and problems getting products that work just exactly as you want.

Of course their communication could have been more clear, but clearly, it's a technical misunderstanding between you and them. They assume you will be using the charger like it is supposed to be used, not for a "special" application.

It's possible that they simply cannot program the charger to your exact specification. It could be a large software development project that could cost at least several thousands of $.

Just my two cents. Of course the communication has been very poor, and if they cannot program a stopping current, the charger is quite limited. No charger should rely only on a BMS signal.

 

[Coulomb]

Well, the actual problem here is ...

I think that a contributing factor is how the company refuses to release specifications on how to program it. Once it's programmed, there are few options for changing it.

There is the Elcon place in California, but no-one else apart from the factory seems to know how to program them. I don't think it's appropriate that every Tom and Harry programs their own, but the details should be made available so that those with appropriate programmers and expertise can change the program.

I mean, are they selling chargers or firmware?

Still, we don't have to buy from them; they can take this attitude if they choose. It's just a shame, since they seem to be pretty good chargers, if only they were a little more flexible.

Of course, I agree with the OP that not programming it as agreed to on the invoice is not good enough. Surely they could give instructions on how to post back the relevant PCB, to avoid Chinese customs problems. I've heard of the manufacturer having to send a complete new unit out, because they could not get the original through their customs for repair (even marked "for repair only"). I can understand their frustration with that situation.

 

[Siwastaja]

I agree that it's ridiculous that you cannot program these chargers by yourself. What if you add cells in your pack or lose a few cells? Not only does the programming cost, it also causes a downtime.

This is one of the reasons I'm building my own charger.

 

[kennybobby]

You may want to go thru Elcon for reprogramming, seems they understand how to meet customer specs, and shipping may be less hassle. http://www.diyelectriccar.com/forums/showpost.php?p=355402&postcount=51

i would still like to see serial output from one of these chargers and try to reverse the programming--i'm surprised that it hasn't been done already.

 

[pm_dawn]

Hi !

I have been in contact with Elcon in Sacramento and they will indeed reprogram the charger for me. But the problem is sending it there and shipping it back will be pretty much what I payed for the charger when buying it. Add to that the charge to reprogram the charger.

What I wanted to do by posting this thread is to inform those that have bought TCCH charger direct from factory that they might not have the charge profile that was agreed upon when ordering. And might actually be overcharging their cell without knowing.

I guess I'm on my own when it comes to whos fault it is. I could probably have been more clear on how I was going to use the charger and why the ending current was so important for this setup.

Still dont know how to solve the problem.

This is also the second charger that goes in to the car. I'm running out of charger funds.......

Regards
/Per

 

[Ziggythewiz]

Well, they did get the end voltage correct, so if you were to specify a lower end voltage it wouldn't matter what current it shuts off at. I think people should be doing that anyway.

No need to taper the current at the end. Just turn it off at 90-95%

 

[pm_dawn]

Well Ziggy, did you read the first post?

The charger is setup to 85,2v on 25 cells. that is 3,408v per cell in CV voltage.
How do you suggest I go any lower than that in ending voltage. If I go any lower the cells will not even charge anything. I think I'm been pretty cautious regarding to end voltage.........

The problem does not go away by lower the end voltage. It just gives me a slower charging and still overcharge of that one lower capacity cell.

I know that it has about 1,5ah lower capacity than the next lowest one.
That is why I have kept an eye on it in the later part of the charging.
That is how I found that if the charger would cut at 85,2 -85,5v and 5A that cell would still be safe and under 3,65v.

Regards
/Per

 

[rwaudio]

It sucks and I hate to stereotype but that's the exactly response I've had from every chinese company that I've ever worked with. Once it's sold they consider the transaction finished regardless of if you got what you wanted/ordered/thought you were buying or even if they made a mistake. The only leverage I've had is a few have them started using paypal, so as long as the product arrives while you can still start a claim you have some level of protection.

It's not an ideal solution but I used one of the simple programmable amp meters to create a charger using some modified Mean Well power supplies. First the power supplies were modified for CC-CV output, then alarms were set up in the meter so that I choose the termination current. Plug in the power supplies and it charges normally in CC mode, it hits the CV point and once the current drops below the pre-set value it triggers the alarm and turns off the charger. It's not ideal, however it has proven reliable and it's used every day in my friends lithium powered Solectria Force, I'm pretty sure he past 10,000km awhile ago using this charger.

 

[Ziggythewiz]

Well Ziggy, did you read the first post?

The charger is setup to 85,2v on 25 cells. that is 3,408v per cell in CV voltage.
How do you suggest I go any lower than that in ending voltage. If I go any lower the cells will not even charge anything. I think I'm been pretty cautious regarding to end voltage.........

Yes, I was mostly referring to anyone else who might order the same product. If your end voltage is at or below 3.4 VPC you won't overcharge the cells, even if the CV stage is longer than you'd like.

They will charge just fine at that voltage, unless you really need that last 1-5%.

 

[Roy Von Rogers]

I'm a bit confused here. You say that charger reached the end point of 85v fine, but didn't stop at 5a, and one of the cells started to overcharge. What was the total voltage at that point when you manually ended the charge??

If it overcharged one of the cells, it should mean that the total voltage should have been higher then the 85.2v you specified.

Btw, I also have a TCCH charger from them ordered via a USA supplier, and I asked for 98v shut off at about 5a, and it doesn't shut of at 5a either, but it doesn't charge over the 98v, it just tapers down to that voltage, forgot what the ending amps are.

I was originally charging 28 HiPower cells, I bought 30 cells, just because they fit exactly in to the square I designated, this way I had two spares in case of a cell failure.

I just recently tried an experiment, and added one more cell to see what would happen, I married the cell in via bottom balancing, so now I have 29 cells charging at 98v, at about 3.4 ending voltage per cell, and its working like a champ.

If you have an extra cell and room, try to see what happens, it may work for you, if you cant get satisfaction from TCCH.

Roy

 

[rwaudio]

I'm a bit confused here. You say that charger reached the end point of 85v fine, but didn't stop at 5a, and one of the cells started to overcharge. What was the total voltage at that point when you manually ended the charge??

If it overcharged one of the cells, it should mean that the total voltage should have been higher then the 85.2v you specified.

Btw, I also have a TCCH charger from them ordered via a USA supplier, and I asked for 98v shut off at about 5a, and it doesn't shut of at 5a either, but it doesn't charge over the 98v, it just tapers down to that voltage, forgot what the ending amps are.

I was originally charging 28 HiPower cells, I bought 30 cells, just because they fit exactly in to the square I designated, this way I had two spares in case of a cell failure.

I just recently tried an experiment, and added one more cell to see what would happen, I married the cell in via bottom balancing, so now I have 29 cells charging at 98v, at about 3.4 ending voltage per cell, and its working like a champ.

If you have an extra cell and room, try to see what happens, it may work for you, if you cant get satisfaction from TCCH.

Roy

For the exact reason that you bottom balance the voltages are all over the place at the top. When you hit the CV point and the current starts to drop off, depending on the cells, some voltages will continue to rise while others will fall. The actual CV point is likely maintained however the individual cell voltages can spread dramatically leading to what the OP talked about with a cell hitting 3.9v, I've also experienced this with my EMW 10kw charger, but I simply reduced the charge voltage from 3.45v to 3.40v per cell and all is well and I'm only down about 0.5Ah. This is also with a bottom balanced pack.

 

[Roy Von Rogers]

Let me tell what I notice the other day charging and rechecking the cells. I noticed some of them coming up quicker then others, and at first I thought that maybe I hadn't bottom balanced them correctly, even though I let them sit for 24 hours or more when I got the final 2.7v per cells.

Some cells came up faster, but as the pack was getting fuller, those cells slowed down and the others were catching up. I actually stopped the charger before it finished, I had to leave. But the cells were all between 3.35 and 3.39v at .8 amps when I took the charger of.

I feel much better now that I put the extra cell in, for I know at least there is no way for them to ever overcharge, unless there is a charger failure, and my JLD404 will take care of that.

Not to mention there is little energy at the top, and its better for the cells to stay at the lower end of the charging cycle.

I'm also amazed that no one has figured out how to change the charging profile on these TCCH chargers. I really don't like the idea of using another electronic device to set the profile via can bus, since I have no use for active balancing schemes.

Roy

 

[pm_dawn]

@ziggy

The problem is that I have charger that does a too long CV phase.
If I could get it to do CC only I would be better off.

The problem when going down in charge current is that cell that are higher capacity tend to fall a little bit in voltage when the current decreases, that makes room for the lower capacity cells to go even higher in voltage without the whole pack going to high.
So @5A most of the cells would be 3,39, leaving one cell to go up to 3,81 and over without the charger knowing.........


@Roy
I dont know if you have ever checked your cell voltages during the last part of the charge. Then you would have observed exactly what rwaudio and I has described here. It is a series string..... all of the cell will not have the same voltage during the last part of the CV phase. I only have 1,5ah difference in my pack, that is about 1,5% on these 100ah cells, and still that makes one cell go really high if the charger keeps charging at those low currents.


@rwaudio
It is a sad experience. For sure. Guess I need to start building my own charges from here on. Damn ! How hard can it be to sell a charger that can be reprogrammed within certain limits and not cost an arm and three of your legs......
I like your solution with the current meter, I guess you mean the lightobject meters. I have been thinking about using the voltage version of them to safeguard the cell that is lower capacity and use that meter to shut off the charger. But using the current version on the dc charge lead might just be a notch smarter. That way I would not risk introducing any parasitic load on any cell. Might be the best solution here. Then I could actually change the ending current by just reprogramming the meter.

Thanks for the idea !

regards
/Per

 

[frodus]

The only problem I see, is if your charger is not plugged in, the alarm will be "active" because the charge current would be under 5A..... so when you plug the charger in, it will already be disabled. You may need to start it manually, then once it's charging, enable the alarm.

So I see it running once the meter sees current flowing, but how does the charger start?

 

[pm_dawn]

@Roy

I'm sorry if I offended you. You must have the most consistant pack I have ever heard of. But on the other hand you really undercharge those cells really nice.

Maybe I should try to go even lower in CV voltage.

I still have the other charger from BMSbattery. That charger was adjustable both for max current and CV voltage. But I could not chage the ending current on that one either.

I have to ask you Roy, when does your charger shut off, at what current ?

Best Regards
/Per

 

[pm_dawn]

The only problem I see, is if your charger is not plugged in, the alarm will be "active" because the charge current would be under 5A..... so when you plug the charger in, it will already be disabled. You may need to start it manually, then once it's charging, enable the alarm.

So I see it running once the meter sees current flowing, but how does the charger start?

Hi !

yes I know that this could be a problem. But I guess some kind of latching relay that is powered by the ac input could solve this. I would of course use the enable cables on the charger to disable it when current falls under the preset.

regards
/Per

 

[rwaudio]

@rwaudio
It is a sad experience. For sure. Guess I need to start building my own charges from here on. Damn ! How hard can it be to sell a charger that can be reprogrammed within certain limits and not cost an arm and three of your legs......
I like your solution with the current meter, I guess you mean the lightobject meters. I have been thinking about using the voltage version of them to safeguard the cell that is lower capacity and use that meter to shut off the charger. But using the current version on the dc charge lead might just be a notch smarter. That way I would not risk introducing any parasitic load on any cell. Might be the best solution here. Then I could actually change the ending current by just reprogramming the meter.

Thanks for the idea !

regards
/Per

Yep, basically just like one of the lightobject meters, however the one I found works on AC input voltage (85-265) instead of the usual DC 9-30v so it just comes on with the charger. I got it on ebay a couple years ago but a quick search didn't bring it up, might be still available somewhere. It's handy, easily programmable and has been reliable.

I had contemplated setting up a short range / full range switch that would switch between the two alarm outputs, one configured with the usual 5A termination (for a 100Ah), and the other configured for just below the CC current, that way there would be no CV phase. You might be a few Ah short on the charge but might help the lifespan of the pack, if you knew you needed all the range you can get, you toggle to the 5A setting. Something similar could be done with a programmable volt meter to terminate at a lower voltage in the CC stage if you wanted to try charging to 80% or something like that. Just make sure the charger will still terminate on it's own and doesn't rely completely on the meter to terminate.

 

[Roy Von Rogers]

@Roy

I'm sorry if I offended you. You must have the most consistant pack I have ever heard of. But on the other hand you really undercharge those cells really nice.

Maybe I should try to go even lower in CV voltage.

I still have the other charger from BMSbattery. That charger was adjustable both for max current and CV voltage. But I could not change the ending current on that one either.

I have to ask you Roy, when does your charger shut off, at what current ?

Best Regards
/Per

You know I don't know anymore..lol. Next time I do a full charge I will have to look at it again. I have a Kill-A-Watt meter on my cord and I just look what the ac amps input to the charger is.

I don't drive a long ways most of the time, if I put 20 to 40 miles on the odometer I just plug it in and go in to my office, and when its time to go home to eat, I just unplug. I may come back later to my office and plug it in again to finish the charge. At times I just look at the KillaWatt meter before I unplug to see the amps. Sometimes its at 8 or 5 amps ac, sometimes its below 1 amp. I don't really care since I don't drive a lot of miles.

But as mentioned earlier, I lifted the truck bed up and charged, just to do a cursory check on the cells, and found what I wrote about.

Now here is my take on your problem. If you have a charger that suppose to shut off at xx voltage, and one of your cells goes too high, there are only two possibilities, either they were not properly bottom balanced, that's getting them to 2.7v per cell, and waiting at least 24 to check voltage and correct, or you have a cell that's lower in capacity then the rest.

Now if you bottom balance as I have stated, and let the charger go, and measure the amp hours going in, the first cell that hits 3.5 v or over, is the lowest capacity cell, and if its under the rated factory amp hours, you need to replace it, or run your vehicle by that ah restriction.

Don't worry about the series thing, if you have 100ah cells and you put in 100ah, the cells are full, and they should be at the voltage the charger is set to. The only reason that one cell is too high, is because of what I stated earlier.

The main thing is the bottom balance, for if that's not done right nothing we talk about has any meaning. And I have to tell, doing it correctly is a PITA.

I know you wanted that thing to turn off at 5 amps, but it is what it is unless they correct it for you. But never the less it should turn of at the voltage you asked for.


Roy

 

[Siwastaja]

Let me tell what I notice the other day charging and rechecking the cells. I noticed some of them coming up quicker then others, and at first I thought that maybe I hadn't bottom balanced them correctly, even though I let them sit for 24 hours or more when I got the final 2.7v per cells.

You probably bottom balanced them just fine and that's exactly the reason why you see what you see; balancing on bottom means unbalancing on top.

You need to top balance if you want them to have even voltages at the end of the charging.

If you want to bottom balance, then you need to adjust the charging voltage low enough that none of the cells exceed 3.65V (or preferably less than that). You can only do that manually by monitoring every cell and lowering the charger voltage as long as any cell gets too high.

For this reason, an unadjustable charger is a nightmare for a bottom balancer. If you top balance, you just get the charger with number of cells times 3.65V or whatever you want to use. When bottom balancing, it's an iterative process that requires at least one measurement run.