Test The Brake Lever Switch help
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omadawn
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Ok, stopped the charge 29.4 V , as expected the charger still had the red light when disconnected. However after LCD reset it displayed 29,2 V. (Had no idea that could happen)
Motor started at this voltage, so one can presume that at 29.4 it will start as well?
Motor started at this voltage, so one can presume that at 29.4 it will start as well?
Dui ni shuo de dui
10 kW
omadawn said:
Instead of presuming you can do some actual testing:
-Charge until it reaches 29.4V, then let it rest for one or 2 minutes and note the voltage (the voltage will go down a little, then stabilize, it's normal). Apparently here your stabilized voltage was around 29.2V
-Check if the motor works (apparently it does since you just did that test already)
-Then charge up to 29.5V, let it rest, note whatever voltage it stabilizes to after 2 minutes,
-Check if the motor spins. If it doesn't then you know that 29.2 Volts was your actual maximum limit. If it does spin, then continue to go slightly higher (29.6, 29.7, etc) until you find our what the actual limit is.
But actually, if you care about making your battery last longer, it is better to slightly undercharge it, so you might want to stick with something between 29 and 29.4V if this works fine already. It won't make much difference in terms of range, but it will make your cells live a longer life.
In which case, try to find a new charger rated at 29Volts and similar charge current, I don't think you can tweak your current charger easily. It is for sure doable (I did it on my motorbike charger in order to limit the max voltage, using a carefully calculated zener diode), but it would need you to open the charger, find out how it works and solder stuff inside, which is not very beginner friendly.
So first, make those tests in order to make 100% sure that the problem is actually indeed a controller max voltage limit (but that's almost 100% sure it is the case if you want my opinion, the symptoms you described over those 4 pages all point into that direction), and once sure, buy a new charger.
omadawn
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Was already considering that as the easiest way to solve this. Will make a new charge to to have more consistent results.
Any way, I was led to assume the Lithium batteries all have an internal circuit protector to stop them from being overcharged.
Is it credible to assume that mine doesn't or, it´s faulty?
Makes sense to consider the LCD reading (after full charge stabilize) be slightly different from the real one in the battery (if this was true the charger might not be faulty and charging precisely at 29.4V) ?
TommyCat
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omadawn said:
This would be my recommendation.. :thumb:
omadawn said:
A typical Li ion battery BMS will start over voltage protection at 4.25vdc plus or minus .025vdc which with a 7S battery would be 29.75 total vdc. So it may well be a defective charger with the BMS saving the battery pack. Although the charger was verified as having an output of 29.7 volts. Close.
omadawn said:
TommyCat said:
omadawn
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Already purchased it, waiting to deliver.
something like this:
https://www.ebay.com/itm/DC-AC-29V-2A-Power-Supply-Adapter-For-Recliner-Sofa-Chair-Massage-Practical-HOT/254256102016?hash=item3b32d83a80:g:lFIAAOSwRq5c-8F0
However with the above charger I am limited to 29.0 V. Can not choose to charge till 29.2 V (for example)
TommyCat
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Very good, a multi meter is a good long term investment!
Taking a close look at your proposed charger replacement, you will see that it is a "power supply" and in my opinion not adequate for properly charging a Lithium Ion battery pack. Look for a specific "charger" for a 24 volt nominal Li Ion battery, at 2 amps or less charging rate.
I've found it impossible to find a charger with your type connector (4 pin). As it's receptacle is built into the scooter...? You may still want to try to open up your existing charger, at least to just see if adjustment is possible. And if further down the road you will want to change the charging wire and connector over to your new charger.
As you can see from this chart, charging and discharging more toward the middle of the battery's nominal voltage zone will help prolong it's life.
But that said. I am a firm believer in being able to do a full charge occasionally in order for the cell groups to be able to balance. With your smaller battery this may not be a huge deal. But I'd still recommend a charger that would go to your full charge voltage. I like my charger that has a percentage switch on it that allows charging to 80, 90, or 100%.
Some I know will go with a 100% charger, then add a diode or 2 to drop the output for a lower voltage charge when they want too.
But most importantly, waiting for the verification and confirmed high voltage lock-out set-point of the controller!
Taking a close look at your proposed charger replacement, you will see that it is a "power supply" and in my opinion not adequate for properly charging a Lithium Ion battery pack.
Look for a specific "charger" for a 24 volt nominal Li Ion battery, at 2 amps or less charging rate. I've found it impossible to find a charger with your type connector (4 pin). As it's receptacle is built into the scooter...? You may still want to try to open up your existing charger, at least to just see if adjustment is possible. And if further down the road you will want to change the charging wire and connector over to your new charger.
As you can see from this chart, charging and discharging more toward the middle of the battery's nominal voltage zone will help prolong it's life.
But that said. I am a firm believer in being able to do a full charge occasionally in order for the cell groups to be able to balance. With your smaller battery this may not be a huge deal. But I'd still recommend a charger that would go to your full charge voltage. I like my charger that has a percentage switch on it that allows charging to 80, 90, or 100%.
Some I know will go with a 100% charger, then add a diode or 2 to drop the output for a lower voltage charge when they want too.
But most importantly, waiting for the verification and confirmed high voltage lock-out set-point of the controller!
omadawn
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Why do you say that? because of the overcharge issues?
what should I look for in the charger´s specs in order not to be cheated?
Ok let me show you my view of that chart:
the blue curve (the ideal one) unfortunately points out to a not practical solution at all.The purple one, however, reflects a more possible use of the charge/discharge process.
Despite that, And as we can see, not so much difference from the white curve (my long term way of dealing with such processes, as in mobile, laptop. shavers etc.)
So I believe the small differences of both curves are more or less compensated by the extra charge/discharges associated to one be using the purple vs the White curve procedure. What do u thing of this?
TommyCat
10 kW
No safeties at all.omadawn said:
And no cc/cv operation 
Please take a closer look at this thread to see what a proper charge is all about.https://electricbike.com/forum/forum/knowledge-base/chargers/38871-how-to-adjust-the-luna-charger-mini-and-advanced
omadawn said:
As discussed...
Bonus if you get the same connector. And naturally that it uses your supply line voltage. (example:120volt) Staying at 2 amps current rating is ok. If in doubt post a link! A reputable dealer is recommended.TommyCat said:
What you charge up to, and discharge down to is all up to your usage, preferences, and priorities. No one size fits all. Distance verses longevity.
Most importantly have you verified that your motor runs at 29.4vdc???
omadawn
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how about this:
https://www.ebay.com/itm/12V-24V-36V-6-60V-Battery-Charging-Control-Board-Charger-Power-Supply-Module/173439309044?var=472142484009
did not have the opportunity yet...Most importantly have you verified that your motor runs at 29.4vdc???
TommyCat
10 kW
omadawn said:
Interesting. Using your charger as a power source and shutting off at your determined set-point. Would not be my choice.(I don't think it allows cc/cv) But if your determined to charge below 29.4 (or have too), perhaps. Beats diodes...
Man, what you can't find on the internet. :wink:
omadawn
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I think it's the best way. I did found an adjustable charger (yes in eBay too!) like you recommended, but I believe the investment ($70) does not compensate in terms of the equipment quality.
This one does, seems perfect to me:
https://www.ebay.com/itm/2A-DC-DC-1-25-30V-12V-Step-down-CC-CV-Power-Board-18650-Battery-Charging-Control/322647992419?epid=2168188646&hash=item4b1f51a863:g:0J0AAOSw9qJaapvG
hummm, that one bellow seems better:
https://www.ebay.com/itm/DC-DC-Boost-Buck-Step-Up-Down-Constant-Voltage-Current-Power-Supply-Module-Case/153508941658?
what do you think?
This one does, seems perfect to me:
https://www.ebay.com/itm/2A-DC-DC-1-25-30V-12V-Step-down-CC-CV-Power-Board-18650-Battery-Charging-Control/322647992419?epid=2168188646&hash=item4b1f51a863:g:0J0AAOSw9qJaapvG
hummm, that one bellow seems better:
https://www.ebay.com/itm/DC-DC-Boost-Buck-Step-Up-Down-Constant-Voltage-Current-Power-Supply-Module-Case/153508941658?
what do you think?
omadawn
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Mistery found. The controller let the motor work at 29.2 V. More than that won't start.
Also the charger's light at 29.4 turned yellow (that's when I hanged up). If I would let it continue it would reach 29.7 and stop the charge by itself (turning to green).
Also the charger's light at 29.4 turned yellow (that's when I hanged up). If I would let it continue it would reach 29.7 and stop the charge by itself (turning to green).
TommyCat
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omadawn said:
Good job getting to the actual cause of the problem!
To a solution...I don't have any experience with those type buck/boost converters you reference. I don't believe they have true constant voltage with automatic reduction of the current and a low current shut-off point. I think you could get them to work with effort and constant surveillance. But with a page of confusing directions, not doing what I actually want, and not knowing for certain they'd work or start my batteries on fire. I'd pass.
(but that's just me, would want something that works out of the box, simple and reliable, like a replacement charger from your original supplier. :wink: But could you trust a replacement? hummmm. )I would still open up your existing charger if possible to see if by chance it's adjustable. But with a yellow light and 4 pins? Perhaps it does have an extra charging monitoring system circuit..? Be interesting to see. But don't want you to break it as you can always just pull the plug when the yellow light comes on.
TommyCat
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Hopefully someone with experience with plastic cases will chime in! My metal one opens easily with 4 screws...
If not... I'd first double check for hidden screws. (even under the sticker, in the wire connector insets, EDIT: under rubber foot pads, etc)
And then probe the spots with the most give (toward the middle), with the smallest blade to carefully, and hopefully, unlock the clips.
If not... I'd first double check for hidden screws. (even under the sticker, in the wire connector insets, EDIT: under rubber foot pads, etc)
And then probe the spots with the most give (toward the middle), with the smallest blade to carefully, and hopefully, unlock the clips.
omadawn
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No I can´t, that would implicate surveillance on all charges, and it is to avoid that we are working on a more practical solution.But don't want you to break it as you can always just pull the plug when the yellow light comes on.
Will try to open it.
Besides the negative and the positive poles, what are the other 2 pins for?
Just a bit outside topic curiosity: when we charge our mobiles 3.6 V lithium trough USB (5 V) are we overcharging it then? (Most chargers are rated more than 4.2 anyway)
omadawn
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Been talking to a colleague (electronic engineer) that scared me a bit about trying to change the charger.
He says it's all about the controller, that should be stopping the charge at a lower voltage point but isn't.
He says that trying to modify the voltage on the charger might result on the 2 A current not dropping when cells are almost charged, and possible burn attached...
He says it's all about the controller, that should be stopping the charge at a lower voltage point but isn't.
He says that trying to modify the voltage on the charger might result on the 2 A current not dropping when cells are almost charged, and possible burn attached...
TommyCat
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I can appreciate the deserved concern which is why I couldn't see using your previous charging options. I disagree on the controller's responsibility towards charging though. As a battery is often charged without the controller even being attached.
Then perhaps you/he means the controller or electronics of the charger... which would be so true.
Back to my recommendation of getting a replacement charger that works properly
Then perhaps you/he means the controller or electronics of the charger... which would be so true.
Back to my recommendation of getting a replacement charger that works properly
TommyCat
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As in the case of 29.7 volts over charge, it could be the battery's BMS over voltage protection. Or the chargers faulty voltage setting.... too close to call. Definitely not the controller's responsibility. Although it may lock-out on over voltage protection as you've seen. But nothing to do with regulating battery charging.
TommyCat
10 kW
omadawn said:
TommyCat said:
...and how to adjust.
omadawn said:
I do not see any trim pots from your picture. Your looking for adjustors like this...
Often the adjustment screws will be coated with paint or glue to keep from moving after setting. Perhaps they might be under the white glue...
What is good to see is that appears that the output of the charger is truly just two wires, with no special extra circuitry. You will have to see how they attach to your 4 pin connector. Just uses 2 pins? or are 2 doubled up... etc.
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