AussieJester
1 TW
Any idea how much i need to transfer too you PayPal account to get my hands on thie kit Mr GGoodrum?
KiM
KiM
Zippy Flightmax / Turnigy lipo testing
- Thread starter johnrobholmes
- Start date
- Status
GGoodrum
1 MW
Ypedal said:Wooohooo !!!
Yeah !
This is perfect ! my 10ah PSI pack is ok for testing but not giving me the range i want, 20ah worth of lipo should be just about right however ! I'm itching to buy some lipo's right now but Winter is very near out here ( -3 celcius this morning, one COLD ebike ride to work ! ) snow won't be far behind.. Best to wait until it all ends and get a fresh pack for next season..
Are you planning to have these available down the road ? or is this a limited time offer ?
I should have them, or some variant of them down the road as well.
-3C? Man, that is cold. It still isn't cool enough here to wear long pants yet.
-- Gary
Hyena
10 GW
Excellent work Gary
This might be a silly question but what if our chargers are set to 4.2v/ cell, or something higher that 4.15v ? Assuming no cell exceeds 4.25v and trips the HVC, will the the cells only be balanced to 4.15v ? Will the balancer sit there 'indefinitely' trying to pull the cells back to 4.15v against the higher voltage output from the charger ?
Speaking of cold weather, I must post a picture for all you northerners of me riding in a singlet and boardies along the beach over the next few months
GGoodrum said:
This might be a silly question but what if our chargers are set to 4.2v/ cell, or something higher that 4.15v ? Assuming no cell exceeds 4.25v and trips the HVC, will the the cells only be balanced to 4.15v ? Will the balancer sit there 'indefinitely' trying to pull the cells back to 4.15v against the higher voltage output from the charger ?
Speaking of cold weather, I must post a picture for all you northerners of me riding in a singlet and boardies along the beach over the next few months
AussieJester
1 TW
Hyena said:Speaking of cold weather, I must post a picture for all you northerners of me riding in a singlet and boardies along the beach over the next few months
You have some rain coming your way Hyena pissing down here today after 30 degree weather few days ago ... :-S
KiM
GGoodrum
1 MW
Hyena said:Excellent work Gary
Thanks.
Hyena said:
I can also do a version with the shunt set for 4.2V, with one resistor change, but I'm really convinced using 4.15V is better for pack longevity.
Hyena said:Speaking of cold weather, I must post a picture for all you northerners of me riding in a singlet and boardies along the beach over the next few months
This last weekend it was still in the 90s here (33C?), so not all of us "northerners" are suffering so much.
-- Gary
mwkeefer
1 MW
Gary,
Nice work man!!! Order coming soon.
A bit of caution... I ordered several meanwell supplies from sure-electronics.com back on the 20th. The order shipped on the 22nd and I received a tracking number from Alan.
For the past 6 days I have watched my shippment bounce back and forth from NANJING to SHANGHI and now this morning when I check the status (this is EMS) it comes up as Delivered but it was delivered in NANJING ?
I have emailed Alan about this but haven't heard back yet.
Just to check myself... I contacted several web vendors and they all had similar issues with shipping from China in the past weeks (2 or so). It seems many of their orders bounced around alot (different suppliers in China, different provinces) before making it out but mine was the only which seems to have redirected back to the factory.
When I spoke with these retailers at least one mentioned some recent press about Lithium batteries being air shipped from China and that retailer is of the opinion that air shipping of these batteries is going to come to an end. I am not crying the sky is falling but this person has been dead on about everything over the past months as they have 15+ years of import / export experience.
Personally I just ordered enough Hobby King cells to last me (and my family) about 2 years of 20-30mi per day on 4 different eBikes. I figure worst case, I can charge them to just above nominal... wrap them and store them in the freezer for a few years.
All this strangeness in the shipments coming from China may be the catching up after their big holiday but its been a while (2-3 weeks right) since the holiday so ... well it still may be nothing but I wanted to be sure to let everyone else know what I (and several others) are seeing with Chinese imports.
Hope it helps!
Mike
Nice work man!!! Order coming soon.
A bit of caution... I ordered several meanwell supplies from sure-electronics.com back on the 20th. The order shipped on the 22nd and I received a tracking number from Alan.
For the past 6 days I have watched my shippment bounce back and forth from NANJING to SHANGHI and now this morning when I check the status (this is EMS) it comes up as Delivered but it was delivered in NANJING ?
I have emailed Alan about this but haven't heard back yet.
Just to check myself... I contacted several web vendors and they all had similar issues with shipping from China in the past weeks (2 or so). It seems many of their orders bounced around alot (different suppliers in China, different provinces) before making it out but mine was the only which seems to have redirected back to the factory.
When I spoke with these retailers at least one mentioned some recent press about Lithium batteries being air shipped from China and that retailer is of the opinion that air shipping of these batteries is going to come to an end. I am not crying the sky is falling but this person has been dead on about everything over the past months as they have 15+ years of import / export experience.
Personally I just ordered enough Hobby King cells to last me (and my family) about 2 years of 20-30mi per day on 4 different eBikes. I figure worst case, I can charge them to just above nominal... wrap them and store them in the freezer for a few years.
All this strangeness in the shipments coming from China may be the catching up after their big holiday but its been a while (2-3 weeks right) since the holiday so ... well it still may be nothing but I wanted to be sure to let everyone else know what I (and several others) are seeing with Chinese imports.
Hope it helps!
Mike
GGoodrum
1 MW
Thanks for the heads-up, Mike. I'm guessing eventually HC will have to start using their warehouses in the US and Europe to make "local" LiPo shipments, but hopefully they will keep their prices low, like they are now.
-- Gary
-- Gary
GGoodrum
1 MW
Here's an illustration I did for the LVC instructions, that shows the connections between four 6s-5000 Turnigy packs and two LVC/Parallel Adapter boards in order to end up with a 12s2p 44V/10Ah configuration:
View attachment 12s LVC-Parallel Adapter Connections-v3.5-02.png
This has a single connector/cable for charging and balancing, independent from the main pack discharge leads. I just did another illustration for the balancer instructions that shows what this single connector plugs into:
I've had some PMs from a couple people who were a bit confused about how these are connected, so these drawings should help, I hope.
-- Gary
View attachment 12s LVC-Parallel Adapter Connections-v3.5-02.png
This has a single connector/cable for charging and balancing, independent from the main pack discharge leads. I just did another illustration for the balancer instructions that shows what this single connector plugs into:
I've had some PMs from a couple people who were a bit confused about how these are connected, so these drawings should help, I hope.
-- Gary
liveforphysics
100 TW
You've made such a simple an elegant solution for LiPo powered E-bikes Gary Big thumbs up!
I must have spent 10 hours soldering balance lead wires and pack leads together, and it's darn tedious work, because you can never shut-off the battery, so you gotta be on your toes the whole time! My end product doesn't offer HVC/LVC, and only balances when connected to an RC charger.
With Garys product here, any goon can just buy some packs, and in a few minutes have them all plugged in together in a minimal labor effort with outstanding safety and functionality. I can't say "thank you" enough for making this missing and much needed product Gary! Thank you!
Big thumbs up! I must have spent 10 hours soldering balance lead wires and pack leads together, and it's darn tedious work, because you can never shut-off the battery, so you gotta be on your toes the whole time! My end product doesn't offer HVC/LVC, and only balances when connected to an RC charger.
With Garys product here, any goon can just buy some packs, and in a few minutes have them all plugged in together in a minimal labor effort with outstanding safety and functionality. I can't say "thank you" enough for making this missing and much needed product Gary! Thank you!
mwkeefer
1 MW
Gary,
I do think your boards are a very nice, all in one package which for the price surpasses all the other hacked together methods weve come up with (we all have different methods right) which never work 100% (hence the KFF). Since people won't need to break down the packs to charge and wont need to solder balance wires (luke your right, ive smoked a few balance leads doing the same thing) and everything is just simpler and neater..
To that end, please forgive me this but... after reading lukes post about any old goon, I had a thought? Do you have a temperature sensor in this design?
I would suggest that if possible for the next version and if not implemented in this one that you add some thermistors or perhaps the little transistor case style LM65 digital sensors.
Over temperature condition should be monitored to make these truly "safe" for any idiot to use (you know someone is going to try to pull 150A out of a 1P pack continuous eventually and blow themselves and your beautiful boards up in the process).
This may not be possible due to the nature of your design, or just not feasible and I suppose that since the boards eliminate the need to break the packs down a person can always install the packs wrapped in a lipo bag for protection from fire.
Just my .02 for what its worth.
-Mike
I do think your boards are a very nice, all in one package which for the price surpasses all the other hacked together methods weve come up with (we all have different methods right) which never work 100% (hence the KFF). Since people won't need to break down the packs to charge and wont need to solder balance wires (luke your right, ive smoked a few balance leads doing the same thing) and everything is just simpler and neater..
To that end, please forgive me this but... after reading lukes post about any old goon, I had a thought? Do you have a temperature sensor in this design?
I would suggest that if possible for the next version and if not implemented in this one that you add some thermistors or perhaps the little transistor case style LM65 digital sensors.
Over temperature condition should be monitored to make these truly "safe" for any idiot to use (you know someone is going to try to pull 150A out of a 1P pack continuous eventually and blow themselves and your beautiful boards up in the process).
This may not be possible due to the nature of your design, or just not feasible and I suppose that since the boards eliminate the need to break the packs down a person can always install the packs wrapped in a lipo bag for protection from fire.
Just my .02 for what its worth.
-Mike
GGoodrum
1 MW
In all my experience with LiPos, I've not ever had a thermal runaway problem while discharging packs, just during charging, and that has always been because a cell, or block of cells were trying to be charged with too high a voltage. I have seen fires that have been the cause of short circuits, but with these super high power packs, a dead short will vaporize connectors, and/or the links between cells, so I'm not sure a temp sensor controlled controller cutoff isn't going to do much, in my opinion.
I thought about adding this feature to the balancer's HVC charge current cutoff circuit, but again, I'm not sure much is gained. Thermal runaways are almost always caused by over-volting a cell, which the individual cell HVC logic will prevent. The only cases I've seen this happen without over-volting was back when ThunderPower released their flawed "V2" 10c lIPo packs, back in 2004. Back then, the cells were not made in humidity-controlled environments, and the cells manufactured in the Korean summer months had water vapor that got trapped in the cells. Eventually, the water would interact with the Lithium (not a good thing...), the cells would puff and go into thermal runaway once any sort of charge current was applied. Anyway, I'll look into what it would take to add a couple temp sensors into the HVC logic for a future version.
-- Gary
I thought about adding this feature to the balancer's HVC charge current cutoff circuit, but again, I'm not sure much is gained. Thermal runaways are almost always caused by over-volting a cell, which the individual cell HVC logic will prevent. The only cases I've seen this happen without over-volting was back when ThunderPower released their flawed "V2" 10c lIPo packs, back in 2004. Back then, the cells were not made in humidity-controlled environments, and the cells manufactured in the Korean summer months had water vapor that got trapped in the cells. Eventually, the water would interact with the Lithium (not a good thing...), the cells would puff and go into thermal runaway once any sort of charge current was applied. Anyway, I'll look into what it would take to add a couple temp sensors into the HVC logic for a future version.
-- Gary
mwkeefer
1 MW
Gary,
For the record... Ive never seen a pack (or caused) damaged durring discharge as long as the LVC is functioning correctly (I have seen and destroyed packs by over discharging then they puffed or flamed durring next charger cycle - I expected this) and I don't know how fast you could detect thermal conditions going haywire... I know from an over volt (intentional) of 5v to the cell you have approx 12 seconds from application of power to burn out but what I don't know (should have stuck a sensor in the pack, now I have to destroy another) is the temperature progression or if the destruction / damage could have been prevented if the power was cut before 2 or 3 or 6 seconds... I didn't do enough testing to determine the available reaction time to see if a pack entering thermal runaway could be detected and shut down fast enough.
In addition... this should not be an issue as you say and with further reflection I'm not even sure you could effectivly detect the runaway before it was too late.
So... I guess just make sure your pack is insulated from your legs and groin areas.. Lipo bags would be best or kevlar/nomex layers inside battery bag (sewn in) similar to a LiPo bag. That would solve the issue all around.
I wonder now... why do all the high end RC chargers have temperature sensors? They must be able to react fast enough to limit the potential for damage (or so I would assume)... I've only triggered one thermal shutdown while using an iCharger 1010B+ and that was only because it was about 90 degrees in my house and I was charging without much air circulation. No damage to the pack or anything though...
Suppose I will have to detonate another pack or two with temp sensors inside logging via eagletree.. I think if I provide external power via USB that I could connect a single cell or two at most and log voltage and current rates in addition to temperature sampling but the max is about 10 samples per second, think the resolution is high enough to justify the destruction of a mid life pack?
-Mike
For the record... Ive never seen a pack (or caused) damaged durring discharge as long as the LVC is functioning correctly (I have seen and destroyed packs by over discharging then they puffed or flamed durring next charger cycle - I expected this) and I don't know how fast you could detect thermal conditions going haywire... I know from an over volt (intentional) of 5v to the cell you have approx 12 seconds from application of power to burn out but what I don't know (should have stuck a sensor in the pack, now I have to destroy another) is the temperature progression or if the destruction / damage could have been prevented if the power was cut before 2 or 3 or 6 seconds... I didn't do enough testing to determine the available reaction time to see if a pack entering thermal runaway could be detected and shut down fast enough.
In addition... this should not be an issue as you say and with further reflection I'm not even sure you could effectivly detect the runaway before it was too late.
So... I guess just make sure your pack is insulated from your legs and groin areas.. Lipo bags would be best or kevlar/nomex layers inside battery bag (sewn in) similar to a LiPo bag. That would solve the issue all around.
I wonder now... why do all the high end RC chargers have temperature sensors? They must be able to react fast enough to limit the potential for damage (or so I would assume)... I've only triggered one thermal shutdown while using an iCharger 1010B+ and that was only because it was about 90 degrees in my house and I was charging without much air circulation. No damage to the pack or anything though...
Suppose I will have to detonate another pack or two with temp sensors inside logging via eagletree.. I think if I provide external power via USB that I could connect a single cell or two at most and log voltage and current rates in addition to temperature sampling but the max is about 10 samples per second, think the resolution is high enough to justify the destruction of a mid life pack?
-Mike
rscamp
1 kW
GGoodrum said:
Hey Gary. I BOUGHT some of those "V2" cells from you back then! They were for helis though, not bikes. I remember talking to you on the phone about replacements at the time. I recently got the bug to put electric assist on a trike and - here you are again! Great implementation - I think I'll have to get me one of these!
GGoodrum
1 MW
Hey Rob --
Yes, it's a small world. You'll find quite a few RC Group veterans over here.
Fun stuff, for sure.
-- Gary
Yes, it's a small world.
You'll find quite a few RC Group veterans over here.Fun stuff, for sure.
-- Gary
Grinhill
10 kW
Thanks for those diagrams a few posts back, Gary.
Another dumb question for you, will the balancer also be able to be configured for other sizes (e.g. 10S) like the LVC's can be?
Another dumb question for you, will the balancer also be able to be configured for other sizes (e.g. 10S) like the LVC's can be?
recumpence
1 GW
Hey Rob,
Heli Mod Man here.
Small world!
What trike do you have? I do not remember if you told me on Bentrider.
(Oh, man we are getting off topic here. Sorry).
Matt
Heli Mod Man here.
Small world!
What trike do you have? I do not remember if you told me on Bentrider.
(Oh, man we are getting off topic here. Sorry).
Matt
GGoodrum
1 MW
Grinhill said:
Yes, in a couple of different ways. You use a 6s balancer with a 5s pack, for instance, with a simple adapter cable. Or, you could build the balancer from the get-go with just five channels populated. If you have a 10s setup, chances are it is made up of 5s packs in series, so you can use two 5s balancers, or two 6s balancers with adapter cables. Unlike the RC balancers, which all balance the cells to the level of the lowest one, these units balance to a fixed voltage (4.15V...), so there's no need to overlap cells from multiple packs. You just need one balancing channel per cell, so for 12s, you need 12 channels. It doesn't matter physically where the channels are (i.e. -- which physical balancer unit they are in...), because each is completely independent.
Ihope I didn't confuse you more.
-- Gary
mwkeefer
1 MW
Hey all,
In the interest of time and space... just a quick note about sure-electronics.com. I placed order with them for a few power supplies which shipped on the 22nd but didn't do anything but bounce back to them... this was the final response I received from customer service before I decided to request a refund (many many missing emails, poor excuses and so on):
So there ready to fire it off again using EMS but they suggest I pay more (6 days in limbo already) to get UPS shipping when I receive 2-3 orders a week from China via EMS without issue (my Hobby King orders are still trucking along as are my sample stock from other vendors)...
I will post status of refund in a short while hopefully I will not have to do the Paypal shuffle = )_
-Mike
In the interest of time and space... just a quick note about sure-electronics.com. I placed order with them for a few power supplies which shipped on the 22nd but didn't do anything but bounce back to them... this was the final response I received from customer service before I decided to request a refund (many many missing emails, poor excuses and so on):
Dear mwkeefer,
Thanks so much for your fast reply.
My colleagues told me today that the Shanghai customs has strengthened the inspection recently and we are so unlucky that the package was returned. Normally, customs guys returns packages for no particular reason at all, so we are also as confused as you are and have no idea why.
The fastest delivery service to USA is UPS. It normally takes 2-3 days. So when we receive the returned package, we can arrange shipment by UPS, of course with your permission and you need to pay more since it is expensive than EMS.
We can also ship your package by HK Post, which is slow and we would not recommend.
Have a good day!
Alan
So there ready to fire it off again using EMS but they suggest I pay more (6 days in limbo already) to get UPS shipping when I receive 2-3 orders a week from China via EMS without issue (my Hobby King orders are still trucking along as are my sample stock from other vendors)...
I will post status of refund in a short while hopefully I will not have to do the Paypal shuffle = )_
-Mike
rscamp
1 kW
recumpence said:Hey Rob,
Heli Mod Man here.
Small world!
What trike do you have? I do not remember if you told me on Bentrider.
(Oh, man we are getting off topic here. Sorry).
Matt
Okay, everyone break into song, "It's a small world after all"...
Matt. My avatar on BROL gives it away, but it is a Trice QNT. The wife has a Q.
Back on topic...
MrKang
100 W
FYI The 6S1P 5Ah 20C are back in stock at hobbycity !! just ordered a couple. be quick before they're out of stock again!
methods
1 GW
I have a feeling that they are going to be in the USA warehouse soon....
When they do it is going to be a good day for ebikers everywhere.
I have decided that when they can be shipped USPS I am going to make a run of custom battery packs.
Maybe four 12S 10Ah batteries - just to see how much trouble it is.
I will outfit them with Gary's awesome BMS kit
They are going to be expensive.....
-methods
When they do it is going to be a good day for ebikers everywhere.
I have decided that when they can be shipped USPS I am going to make a run of custom battery packs.
Maybe four 12S 10Ah batteries - just to see how much trouble it is.
I will outfit them with Gary's awesome BMS kit
They are going to be expensive.....
-methods
mwkeefer
1 MW
Sorry bud.. I have done it a few times (focused on work at hand), hell for some reason the term "pencil iron" sticks in my mind and I try to hold it like a pencil = (Hyena said:
Just an update - I received my Mean Wells from sure-electronics today - Thanks Alan. I've already shot the unboxing, the units and I've calibrated them all to 20.7v they will go lower. I will post a thread later with a complete review once I have a chance to clear my camera...
Does anyone (hyena, gary, ??) know if the Meanwell S-350-24 can be safely connected in series for combined voltages? It would be easier (and less likely to end up with KFF again) to charge the whole pack at once but since these are 14A rated at 24v... I can charge my 15AH15S pack in series or as 3P5S one per charger fora 1C charge rate either way.
Do I need to open the unit and seperate a case ground or anything? They have a screw terminal for earth ground which makes me think the case is isolated (and the way the manual shows proper install, would be nice if they specified that these could be run in parallel or series? If nobody is sure, I'll just crack it open and look for the protection diodes and such.
Thanks in advance!
-Mike
GGoodrum
1 MW
Mike -- These are definitely fully isolated and can be used in series. What I did with miner is stack two, one on top of the other, connect one power cord to the bottom unit, with a connection up to the 2nd unit. I then used some 14-gauge wire for the charge leads, terminated in two Powerpoles. I calibrated both of mine to 24.9V (4.15V x 6), and the units are connected in series so what I end up with is 48.9V at 14A.
This charge cable plugs into a short dongle I have coming off the balancer. Speaking of the balancer, I have some new pics:
View attachment 12s LiPo Balancer with HVC Cutoff-01.jpg
View attachment 12s LiPo Balancer with HVC Cutoff-03.jpg
View attachment 12s LiPo Balancer with HVC Cutoff-04.jpg
The basic balancer circuits are on the lower PCB, which has the shunt resistors and BD136 shunt transistors mounted from the bottom, so they can make thermal contact with the bottom of the box. I switched to the square ceramic power resistors that Digikey sells, instead of the round ones, because the coating can get scraped off of these, which could cause a short. Anyway, these eliminate that potential problem and there is more flat surface area, up against the case, so the heat transfer is better.
The upper board serves two purposes, first as a replacement lid that has holes for the LEDs (I hate drilling these, as I can never seem to get them perfect, even with a drill press...), and connections for a board-mounted 18-pin AMP connector. The second purpose is for the HVC Cutoff parts, which are mounted on the underneath side. Finally, since I almost always use a WattsUp meter, while charging, I decided to add connection holes for it as well. This top board/lid connects to the balancer board via two 7-pin JST-XH connectors and a single JST-BEC 2-wire pigtail.
The single 18-pin AMP connector is used to balance and charge the pack. The main charge current is routed via four of the pins, two for the + connection and two for the - connection. Each of these pins are rated for 9A ea, but I've run more than that through these before, with no issue. My Meanwell setup puts out 14A, so this is fine. Anyway, there is a single charge/balance cable with a matching 18-pin plug on each of my 12s3p packs.
Operation is pretty simple, you just plug in the pack, plug the supply to the balancer and plug in the supply. The 12 LEDs all start out orange, while in the CC charge phase. As the shunts start to come on, the LEDs will transition from orange to green. When the shunt is fully conducting, which happens at 4.15V, the LED is solid green. If an errant block of cells tries to go above 4.25V, the LED for that channel will switch to solid red, and the charge current will be cutoff, until the shunt pulls the voltage for that channel back down to a safe level. This is not the same as the PWM "throttling" on the BMS boards, because there is a little bit of hysteresis built into the HVC cutoff logic, so the voltage needs to drop a bit more than it would by just cutting the current off. Anyway, this is meant to be a safety feature, to keep the packs from lighting up if there are some bad cells. Normally, healthy cells won't ever be far enough out-of-balance that the cells get that high. The worst case is if you have one cell/block of cells that has lost a lot of its capacity, so it ends up getting full way before the rest. That will where this HVC cutoff feature will likely be enabled.
Anyway, all you do is wait for the LEDs to all turn green, and check to see that the charge current on the WattsUp has dropped to about 660-670 mA. At that point all the current is being absorbed by the shunts, and the cells are as full as they are going to get.
I'm still working on the instructions, but I hope to have those complete by tomorrow, and then I'll start a new thread, and make them available on my site. Initially, I'm going to do this in complete kit form, which is why I am doing very detailed assembly instructions, with lots of pics. These aren't hard to build, if you know your way around a soldering iron, but it does take a fair amount of time.
-- Gary
This charge cable plugs into a short dongle I have coming off the balancer. Speaking of the balancer, I have some new pics:
View attachment 12s LiPo Balancer with HVC Cutoff-01.jpg
View attachment 12s LiPo Balancer with HVC Cutoff-03.jpg
View attachment 12s LiPo Balancer with HVC Cutoff-04.jpg
The basic balancer circuits are on the lower PCB, which has the shunt resistors and BD136 shunt transistors mounted from the bottom, so they can make thermal contact with the bottom of the box. I switched to the square ceramic power resistors that Digikey sells, instead of the round ones, because the coating can get scraped off of these, which could cause a short. Anyway, these eliminate that potential problem and there is more flat surface area, up against the case, so the heat transfer is better.
The upper board serves two purposes, first as a replacement lid that has holes for the LEDs (I hate drilling these, as I can never seem to get them perfect, even with a drill press...), and connections for a board-mounted 18-pin AMP connector. The second purpose is for the HVC Cutoff parts, which are mounted on the underneath side. Finally, since I almost always use a WattsUp meter, while charging, I decided to add connection holes for it as well. This top board/lid connects to the balancer board via two 7-pin JST-XH connectors and a single JST-BEC 2-wire pigtail.
The single 18-pin AMP connector is used to balance and charge the pack. The main charge current is routed via four of the pins, two for the + connection and two for the - connection. Each of these pins are rated for 9A ea, but I've run more than that through these before, with no issue. My Meanwell setup puts out 14A, so this is fine. Anyway, there is a single charge/balance cable with a matching 18-pin plug on each of my 12s3p packs.
Operation is pretty simple, you just plug in the pack, plug the supply to the balancer and plug in the supply. The 12 LEDs all start out orange, while in the CC charge phase. As the shunts start to come on, the LEDs will transition from orange to green. When the shunt is fully conducting, which happens at 4.15V, the LED is solid green. If an errant block of cells tries to go above 4.25V, the LED for that channel will switch to solid red, and the charge current will be cutoff, until the shunt pulls the voltage for that channel back down to a safe level. This is not the same as the PWM "throttling" on the BMS boards, because there is a little bit of hysteresis built into the HVC cutoff logic, so the voltage needs to drop a bit more than it would by just cutting the current off. Anyway, this is meant to be a safety feature, to keep the packs from lighting up if there are some bad cells. Normally, healthy cells won't ever be far enough out-of-balance that the cells get that high. The worst case is if you have one cell/block of cells that has lost a lot of its capacity, so it ends up getting full way before the rest. That will where this HVC cutoff feature will likely be enabled.
Anyway, all you do is wait for the LEDs to all turn green, and check to see that the charge current on the WattsUp has dropped to about 660-670 mA. At that point all the current is being absorbed by the shunts, and the cells are as full as they are going to get.
I'm still working on the instructions, but I hope to have those complete by tomorrow, and then I'll start a new thread, and make them available on my site. Initially, I'm going to do this in complete kit form, which is why I am doing very detailed assembly instructions, with lots of pics. These aren't hard to build, if you know your way around a soldering iron, but it does take a fair amount of time.
-- Gary
AussieJester
1 TW
Veeery nice Gary i see i will have a use for my WattSUp meter again too
KiM
KiM
mwkeefer
1 MW
Gary,
Thanks for like the 3rd time today - for the pointer to the guys at sure-electronics.... it was a little sketchy for a minute but they came through, these are great!
So if you stacked them the cases are floating... Ill just have to check between for continuity between output GND and case / earth to be safe (cause Ive had enough KFF but more because they took > 2 weeks to get here, don't want to wait for replacements if I blow these up).
The balancers are coming up nice... what will the kit boards cost? Nice with the AMP connector (I thought you used an X86 processor core - jk).
I see you say, monitor watts up when all LEDs are green to determine when CV is finished? Does this mean the boards won't self disengage (latching until charger power removed)?
-Mike
Thanks for like the 3rd time today - for the pointer to the guys at sure-electronics.... it was a little sketchy for a minute but they came through, these are great!
So if you stacked them the cases are floating... Ill just have to check between for continuity between output GND and case / earth to be safe (cause Ive had enough KFF but more because they took > 2 weeks to get here, don't want to wait for replacements if I blow these up).
The balancers are coming up nice... what will the kit boards cost? Nice with the AMP connector (I thought you used an X86 processor core - jk).
I see you say, monitor watts up when all LEDs are green to determine when CV is finished? Does this mean the boards won't self disengage (latching until charger power removed)?
-Mike
- Status