Power Supply for PowerLab8 v2

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Re: Power Supply for PowerLab8 v2

Postby coolice » 15 Nov 2018, 13:21

Good Afternoon Guys and Gals.

Having been linked to this site by Jeffrey, as we discuss his power supply requirements, I felt it might be a good idea to join and provide as much advice as I can from the power supply and charger perspective based on what I have learnt in my many years in the RC hobby and for my line of work.

For those that don't know me, I build standalone power supplies from repurposed server units and custom built charge cases for the RC & UAV guys. However on a handful of occasions now, I have also sold power supplies to power chair users.
Here is my web site: http://www.coolice.co.uk which will show you some of the power supplies and cases I build. But bascially I build setups to buyers budgets and can advise on the equipment that will work well for you also.

I'll be honest, one of the reasons for my posting is due to feeling you may be spending a lot more money on the charging setup than you really need to.
Don't get me wrong, the Revolectrix range of chargers is very nice and desirable, but is not cheap. For a little more than the cost of a PL8, you could have one of my small FPV charge cases which uses an ISDT Q6 Plus 300 watt charger, 25 volt 350 watt PSU, all housed in a high impact case for simplicity and postability.
Of course there are many options still, with more powerful setups available in the charging and power supply line. But from what I have read and been told so far, you are far from needing anything more than a 14 amps charge rate.
The iCharger X6 at £100 for the charger is not only very capable, small, light and thus easy to carry around, but good value to.

I've seen some talk about 48 volt power supplies also, which I have been playing around with recently to and there is one make that works very well, which are called Eltek. These I can program the output voltage from anywhere between 43.6 to 53.6 volts from memory and also the current limit can be set to 10, 20, 30, 40 amps. These units are very popular in the eBike circles for charging the bikes packs.
Prices on these vary and I have atleast 6 ~ 8 in stock, which I got at a good price to sell on, so there is options there to. ALogn with other power levels on the more traditional server units I sell a lot of to.

I won't go on any more for now, but if you would like me to start my own topic so we can discuss further how I may be able to help you or others, please let me know and I shall do so.

Ian Contessa
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 15 Nov 2018, 15:01

ISDT Q6 Plus 300 watt charger, 25 volt 350 watt PSU, all housed in a high impact case for simplicity and postability.
Of course there are many options still, with more powerful setups available in the charging and power supply line. But from what I have read and been told so far, you are far from needing anything more than a 14 amps charge rate.
The iCharger X6 at £100 for the charger is not only very capable, small, light and thus easy to carry around, but good value to.


Those are all tiny unsophysticated 6S chargers. They wont do what we need. By a long way.

The only charger that can PROPERLY be configured to charge large 24V LiFeP04 packs, and lead packs is the PL8v2 and only then because I got them to change many parameters in the charge algo and allowable settings over a full year and because I have deeper access to the user settings than officially allowed!
Those other chargers wont do what we need at all for many reasons. And we really need proper PC connectivity and graphing to problem solve and control at times as well. Also, most of us regularly charge at 28.80V and 40A. Inc myself. So we need at least 1152 watts output plus 15% for losses is about 1325 watts input. So a 1500W 24V power supply that is truly stable under a high frequency pulswidth load is what is needed by most. Slow charging with smaller supplies when travelling may be a different matter.

By way of example, many here are charging 8S X 130Ah to 240Ah lithium packs rated at up to 5C charge! So a 14A charge would take forever. Not to mention we need complex charge termination configuration where we can control termination currentt, balance details and start point, CV time limits and cell balance spread etc etc. Those chargers you show, and even the expensive ichargers are frankly hopless in comparison.

Heres my usual charge setup that is run at max power with 2x 1200 watt power supplies at once and at 40A to charge a 13S (6S and 7S) split pack

http://www.wheelchairdriver.com/BM3-con ... on/PL8.jpg Normal 13S setup with 2x 1200 watt isolated supplies.
Typical battery: This is 120Ah 8S and 5C charge compatible. So 40A just tickles it! Still takes 3 hours and a half... http://www.wheelchairdriver.com/images- ... hair-7.jpg
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Re: Power Supply for PowerLab8 v2

Postby coolice » 16 Nov 2018, 12:12

Burgerman wrote:
ISDT Q6 Plus 300 watt charger, 25 volt 350 watt PSU, all housed in a high impact case for simplicity and postability.
Of course there are many options still, with more powerful setups available in the charging and power supply line. But from what I have read and been told so far, you are far from needing anything more than a 14 amps charge rate.
The iCharger X6 at £100 for the charger is not only very capable, small, light and thus easy to carry around, but good value to.


Those are all tiny unsophysticated 6S chargers. They wont do what we need. By a long way.

The only charger that can PROPERLY be configured to charge large 24V LiFeP04 packs, and lead packs is the PL8v2 and only then because I got them to change many parameters in the charge algo and allowable settings over a full year and because I have deeper access to the user settings than officially allowed!
Those other chargers wont do what we need at all for many reasons. And we really need proper PC connectivity and graphing to problem solve and control at times as well. Also, most of us regularly charge at 28.80V and 40A. Inc myself. So we need at least 1152 watts output plus 15% for losses is about 1325 watts input. So a 1500W 24V power supply that is truly stable under a high frequency pulswidth load is what is needed by most. Slow charging with smaller supplies when travelling may be a different matter.

By way of example, many here are charging 8S X 130Ah to 240Ah lithium packs rated at up to 5C charge! So a 14A charge would take forever. Not to mention we need complex charge termination configuration where we can control termination currentt, balance details and start point, CV time limits and cell balance spread etc etc. Those chargers you show, and even the expensive ichargers are frankly hopless in comparison.

Heres my usual charge setup that is run at max power with 2x 1200 watt power supplies at once and at 40A to charge a 13S (6S and 7S) split pack

http://www.wheelchairdriver.com/BM3-con ... on/PL8.jpg Normal 13S setup with 2x 1200 watt isolated supplies.
Typical battery: This is 120Ah 8S and 5C charge compatible. So 40A just tickles it! Still takes 3 hours and a half... http://www.wheelchairdriver.com/images- ... hair-7.jpg


Good Morning.

Thank you for the information, you know a lot more about the intergration of batteries into the power chairs then myself. I can just speak from the perspective of an RC user that uses the very same packs and chemistrys, admittedly in smaller capacities, but using the same techniques to promote good life span and safety.

Oh yeah, the ISDT chargers are very basic in their features with just charge, discharge and storage modes. For what they are they work well, no comparison to the PL8, but then they shouldn't be at a fraction the price. The iChargers are different and show in their price difference, as they rival the PL's.

I'm curious with the large 24V LiFeP04 packs though, as you can't charge and balance them as a complete pack on the PL8 V2, as it can only monitor 8 cells at a time. So I am guessing you're either using a seperate BMS and just feeding power into the pack to charge, which then negates the use of the PL8 V2 really I suppose, or breaking the multi cell packs down into banks of 8 cells to be charged in parallel? The latter being the logical conclusion to me.

There aren't many 8 cell capable chargers, the 4010 DUO can do up to 10s and the cheaper 3010b also, so that limits your choices and if you are using the PL8 then this helps with you being able to advise others from vast years of experience.
Lesser chargers would need the banks splitting into 4x 6s packs to parallel charge at one time, which would then open the door to other chargers as they all have the ability to charge lithium polymer and ion cell chemistrys. But this adds more cost in the pack wiring.

PC connectivity is handy, but after initial setup of the charging memory allocation to suit your pack type/wiring configuration, what extra is needed after this point?
Surely the one good indication of pack quality is the IR (internal resistance) of the individual cells to determine the state of the pack as a whole and to help identify single cells on the way out. Which you can gleen from the stock PL8 V2 LCD anyway, so can do away with the laptop until changes are needed.
The user interface of the PL's isn't great sadly, hence their Bump Controller which adds another dimension and might also be handy going by what you have said above with the wireless monitoring and charger setup available through that. This is accessible from an Android or IOS device also which is neat, so a PL8 with Bump could be a good option for some.

That last photo is a monster pack, so yeah I have no doubt 40 amps would only tickle it. But then again, ideally you wouldn't want to charge at 5C at all times as that will degrade the pack quicker over time and I am guessing this setup isn't cheap. However, I can see that on the odd occasion to keep mobile, having the ability to do so would be great, so catering to that need as well would be handy.
This is where the eBike way of a powerful power supply and seperate BMS setup might work best, which I have seen here already in other topics and am enjoying reading them.

In any case I'm not trying to argue with you at all, but merely learning what is used and at the same time give another perspective as we're still just charging batteries, just in differing applications.

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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 16 Nov 2018, 12:46

Oh yeah, the ISDT chargers are very basic in their features with just charge, discharge and storage modes. For what they are they work well, no comparison to the PL8, but then they shouldn't be at a fraction the price. The iChargers are different and show in their price difference, as they rival the PL's.

Thier charge algos and safety certainly doesn't. There are numerous cell gap issues and related timers that trip us up with those, as well as balance start voltage issues, and termination current/timer setting problems. The PL8 was just as bad, but I worked with them to fix the firmware issues and option for lead, and LiFePO4 packs. Not so the iChargers. And also the PL8 are more robust electrically for a number of reasons.

I'm curious with the large 24V LiFeP04 packs though, as you can't charge and balance them as a complete pack on the PL8 V2, as it can only monitor 8 cells at a time.

24V is actually 8x 3.2V nominal. So the 8S PL8 works fine. I do have a 13S pack, in one chair, and it is electrically charged as a 6S and a 7S pack, using one connector, with 14 balance wires, and 2 power connections, via 2x PL8 on 2 separate isolated power supplies. It is charged at between 16 and 40A depending on how much of a hurry.

Charging just 2 cells here...
http://www.wheelchairdriver.com/BM3-con ... arging.jpg

6S and 7S charging one 13S battery pack.
http://www.wheelchairdriver.com/BM3-con ... arging.gif

So I am guessing you're either using a seperate BMS and just feeding power into the pack to charge, which then negates the use of the PL8 V2 really I suppose, or breaking the multi cell packs down into banks of 8 cells to be charged in parallel? The latter being the logical conclusion to me.

BMS! NEVER terrible things. A source of battery and usage issues and ruined packs! Just charge as 2 packs, via PL8 with isolated supplies. Dead simple. But remember that most of our chairs are just 8S and 24V so ONE pl8 is fine.

There aren't many 8 cell capable chargers, the 4010 DUO can do up to 10s and the cheaper 3010b also, so that limits your choices and if you are using the PL8 then this helps with you being able to advise others from vast years of experience.

And the fact that they are more reliable, and the charge algo actually works and the PC software and charger makes the PL8 far superior!
Lesser chargers would need the banks splitting into 4x 6s packs to parallel charge at one time, which would then open the door to other chargers as they all have the ability to charge lithium polymer and ion cell chemistrys. But this adds more cost in the pack wiring.

Never seen a lesser charger that can do the job PROPERLY yet! I have tried all the top brands, and even the other Cellpro chargers.
PC connectivity is handy, but after initial setup of the charging memory allocation to suit your pack type/wiring configuration, what extra is needed after this point?

Its essential to me. It allows you to see problems or bad cells, or high self discharge on one group etc developing. And its simply easier than pressing buttons! I fine tune the settings such as termination current, or CV timeout as the pack ages by looking at the curves and data. Remember that I have a higher level of access to the charge presets than normal users too.
Surely the one good indication of pack quality is the IR (internal resistance) of the individual cells to determine the state of the pack as a whole and to help identify single cells on the way out. Which you can gleen from the stock PL8 V2 LCD anyway, so can do away with the laptop until changes are needed.

Thats one parameter. And on long cables, not very accurate.

The user interface of the PL's isn't great sadly, hence their Bump Controller which adds another dimension and might also be handy going by what you have said above with the wireless monitoring and charger setup available through that. This is accessible from an Android or IOS device also which is neat, so a PL8 with Bump could be a good option for some.

I never use the PL8s interface. Its controlled by PC or laptop. The bump controller is too limited in the parameters it can set or configure. So not much use to me. Like opening your toolbox and seeing just pliers and 1 screwdriver! It also doesn't allow any way to configure anything without a fight. The PC software makes it look silly.

That last photo is a monster pack, so yeah I have no doubt 40 amps would only tickle it. But then again, ideally you wouldn't want to charge at 5C at all times as that will degrade the pack quicker over time and I am guessing this setup isn't cheap
.
Well 5x a 120Ah pack would require a 120Ah x 40A = 4.8KW charger. So say 5.5KW power supply!!! So theres not much danger of that.
At 40A we are charging at ONE THIRD of 1C!

In any case I'm not trying to argue with you at all, but merely learning what is used and at the same time give another perspective as we're still just charging batteries, just in differing applications.


I have been flying RC inc jets, and pulse jets, and electric in helis and multi-rotors since I was a kid. And am now 58. So I understand where you are coming from. But this is a different world! And no arguments here. But for big LEAD or LiFePO4 packs there isnt any alternative thats viable to the PL8 unless we start that massive fight to get the manufacturer to fix everything again. Even the new bump controller built in cellpros that look all carbon fiber dont work. Firmware changes with Safety nazi stuff built in stops us setting the settings that work best. Same prob with the double PL8. And every other icharger I looked at.
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Re: Power Supply for PowerLab8 v2

Postby foghornleghorn » 16 Nov 2018, 13:13

Burgerman wrote:Its essential to me. It allows you to see problems or bad cells, or high self discharge on one group etc developing. And its simply easier than pressing buttons! I fine tune the settings such as termination current, or CV timeout as the pack ages by looking at the curves and data. Remember that I have a higher level of access to the charge presets than normal users too.

Does that mean anyone else buying a PL8 isn't going to get something quite as useful as yours?
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 16 Nov 2018, 13:29

If you use my presets, as are dotted about all over this forum, then you get exactly what I do. With a load of safety nazi setting adjusted or removed, some parameters widened such as cell voltage spread limits etc. So you dont run into safety charge bullshit on huge packs for eg.
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Re: Power Supply for PowerLab8 v2

Postby coolice » 16 Nov 2018, 19:18

Evening.

I did forget you use Li-Ion over polymer, so the nominal volate of each cell is lower.[/quote]
Lithium ion phosphate. Totally different to charge than polymer or lithium ion cobalt type cells.

As with foghornleghorn above, your comments on the charger parameters did lead me to belive you had some back door access within the Revolectrix software opened up, which would then not be available to the average buyer. But your last post says this isn't the case and it is just the parameters you input using the PC interface for simplicity that tunes the PL8's charging preset to suit the packs you are using.
Thus once set do not need touching.

The PC interface provides you with a graphical view of the cells behaviour during the charge cycle, which again unless you were building packs to sell I don't see the end user messing around with that very much. i'd imagine they would just want a plug and play setup that is safe and reliable, with the simple tell tale feedback to give an indication on the packs state of health.
The LCD interface has never been one of my favourites, it works but is clunky.

I'm surprised not to see you offering PL8's with the presets already flashed to them for ease, would make a nice out of the box working package.

Here is a photo of one of my 2400 watt, 12/24 volt units. Bit smaller than the lab PSU's.

EDIT BURGERMAN, I MAY HAVE MESSED UP YOUR POST A LITTLE IN ERROR... WHAT CAN I SAY. IAM AN IDIOT! :cussing
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 16 Nov 2018, 19:53

Evening.

I did forget you use Li-Ion over polymer, so the nominal volate of each cell is lower.

Lithium ion phosphate. Totally different to charge than polymer or lithium ion cobalt type cells. Very flat discharge curve, and right at the end they go ballistic. Self discharge over even a day on a big pack means they can go out of balance, only right at the top above 3.45V per cell.

As with foghornleghorn above, your comments on the charger parameters did lead me to belive you had some back door access within the Revolectrix software opened up, which would then not be available to the average buyer. But your last post says this isn't the case and it is just the parameters you input using the PC interface for simplicity that tunes the PL8's charging preset to suit the packs you are using.


I do have a back door access. And on the PL8 alone, persuaded the manufacturer to make a few changes to the firmware. Only 3.33 is of any use to us. But I can save the profiles with a few invisible and non official settings and removed some barriers etc and make them work better for our purposes. By uploading modded profiles that you cant do with normal user access here.

Thus once set do not need touching.

How are you going to fine tune the termination current, to match each pack? For eg. Without fine tuning? You dont do this with hobby stuff for various reasons such as lower impedance and relatively high balance current to cell Ah ratios. So no need. Or fine tune the balance voltage start point. If you start balancing LiFePO4 packs that are large below a certain voltage then the balancer UNBALANCES the pack at the top. Not to mention some are charging lead/lithium combo packs! Theres no two packs the same even on my own chairs.

The PC interface provides you with a graphical view of the cells behaviour during the charge cycle, which again unless you were building packs to sell I don't see the end user messing around with that very much. i'd imagine they would just want a plug and play setup that is safe and reliable, with the simple tell tale feedback to give an indication on the packs state of health.
The LCD interface has never been one of my favourites, it works but is clunky.

I have literally never used the LCD interface. Other than to see if it worked!
If that was the case, there wouldn't be literally hundreds of screenshots of packs with problems shown on packs people are building on this forum. The graph, and the 8 separate curves show up loose connections or duff cells that we otherwise wouldn't see. Etc. Long before the huge packs get loaded into a chair. And show if a cell or group of cells has a problem long before that becomes a bigger problem. It also allows us to fine tune the charge parameters to suit each battery and situation. After this we can just monitor every 5th or 10th charge. And also see how crap BMS are! Or other manufacturers chargers. If we monitor a charge. The lack of powerful PC control, and monitoring software would be a dealbreaker.

I'm surprised not to see you offering PL8's with the presets already flashed to them for ease, would make a nice out of the box working package.

Theres nothing to flash. And theres no "standard" set of settings that work for all. I just upload a preset for someone if they want me to do so. Or they can take an existing one off here and adjust the parameters to suit their own use.
Because I fine tune them to suit peoples packs so that they charge correctly. And they fine tune them further after looking at graphs to tailor the voltages to suit where charge balance starts, and the termination current to suit different cell types and pack sizes, etc. For E.g. some are using the PL8 to charge both LiFePO4 and lead batteries linked in parallel and this needs to be fine tuned to give a long enough CV for lead but have charge voltage set to a compromise, as well as termination current fine tuned. No two setups are the same! I imagine everyone is using slightly different settings. Esp for lead, where there are a multitude of types and sizes, and charge currents etc.

Here is a photo of one of my 2400 watt, 12/24 volt units. Bit smaller than the lab PSU's.

No picture?

I am using two of these 3000 watt adjustable supplies. 0-60V and 0-50A capable... With 3 stage charger fully adjustable for lead built in. BELOW:
You might look into these. Very high quality, electronics, and very compact. But also available with or without the fancy case.


3kw. Very cheap. Very well built electrically for rack use by huge telecoms company. ZXD2400 under the fancy skin. With custom adjustable output. Available from Shirley_hkg on this forum.
As used by many of us here now. Its got a very adjustable 3 stage Lead acid charger built into it too.
On mine, the anderson is used for anything beyond 20A as its more reliable as a high current connector. I charge a 24V battery system, lead at 29.4V and at 50A with this. And run the PL8 too.

0-60V and 0-50A capable.

viewtopic.php?f=2&t=7670&start=60
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 16 Nov 2018, 20:47

http://www.wheelchairdriver.com/gopro/3stage.mp4

Movie above. Here its set as a 3 stage charger. Instead of a simple power supply. One of the FEW lead chargers that actually does things properly. Unlike almost all hobby ones. But that battery is 99.99% charged already. So you can watch it transition to float at .2A charge.

Limited here to a 12A and 28.20V (correct for gel), 3 stage because thats the maximum the connector/powerchair here allows.
With transition to FLOAT at the point where CV current falls to 0.2A and at continues at my chosen 27.20V.

Normally I set it to 24V and 50A to power a PL8.
Or I charge lead via an Anderson connector at 50A. A cheap, powerful, compact and very adaptable tool/3kw power supply.
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 21 Nov 2018, 23:54

Hopefully I'll be setting up a new PL8 for charging the MK gels via the XLR plug soon.

Is the profile in this post still the best?
(26 May 2018, Re: To Buy a PL8 - Accessories, attachment: "Lead MK GEL 12A Max With XLR plg.PS8.zip")
viewtopic.php?f=2&t=7925&start=30#p119575

Has anyone used the PL8 software with a virtualised Windows running on a Mac?
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 22 Nov 2018, 00:01

Should be.

Termination is set to 100mA. And if the battery never achieves that low figure after 8 hours of CV it can be raised a little at a time till it does. Its time limited to 8 hours CV too. So will stop after this time. This is for a deep cycle battery used for a full cycle/day.

If you are just topping up a chair thats been say 1 mile, set C to 4 hours limit.
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 22 Nov 2018, 00:50

Thanks a lot.

I rarely get 8 hours straight to charge. If I stop a charge after 4 or 5 hours, use the chair a bit inside, then charge again for another couple of hours, is that nearly as good as a continuous charge? Or does it need the uninterrupted CV time for the best charge?
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 22 Nov 2018, 00:53

No thats the problem. You MUST finish a full total charge at least every few days or the battery ends up sulfated. Thats why mobility chargers are so crap.

After a few hours charging it might be 99% charged.. That last 1% is important! It may double the charge time.
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Re: Power Supply for PowerLab8 v2

Postby shirley_hkg » 22 Nov 2018, 02:20

You sell batteries . I trust you . cheers
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 22 Nov 2018, 02:27

Dont trust me, those details are MK's own, from their own tech sheets. Not mine.

Yet they write this sort of thing on the battery. Because they CAN be charged at 29.6!!
Its safe, its just that it ruins them!
Better for sales. download/file.php?id=9482&mode=view
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 22 Nov 2018, 16:40

Burgerman wrote:Dont trust me, those details are MK's own, from their own tech sheets. Not mine.

Yet they write this sort of thing on the battery. Because they CAN be charged at 29.6!!
Its safe, its just that it ruins them!
Better for sales. download/file.php?id=9482&mode=view

I was wondering about that. I was looking for something definitive on their site, like that chart and diagram you attached earlier. I wanted to show someone that a manufacturer says that voltage above 28.2 for a 24v system would be bad for it. All I found was their retail / promo material which says up to 14.6. Do you have a link to the technical stuff on their site? Or is it behind a wall?

Even on this FAQ which says gels never need to be equalized (in the "Broadband/CATV Questions" section for some reason), it says "The correct charging voltage for a Gel battery is 14.4 to 14.6 volts maximum at 68°F."
http://language.mkbattery.com/content_c ... q#catvfaq1
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 22 Nov 2018, 20:17

Theres a massive difference between what WORKS, as in sell sheets and written on a battery. And what is best for longevity and cycle like. They want to offer a wide voltage range. Because otherwise they lose sales.



Chargers... Almost every mobility charger claims to be universal and that they can charge AGM or Gel, or any sealed battery. They do this with the CC/CV and sometimes float algo. So 2 or 3 stage. And they all charge the MK at too high voltage. Typically 14.4 to 14.6 or even 29.2V per battery. So they charge at too high voltage. Its perfectly true, you CAN charge these at 14.6V as long as you dont care that it reduces service life very markedly.

See the chart on here showing the result of charging above the recommended voltage! You lose 60% of the battery service life, by charging just .7 volt too high. And the correct voltage is 13.8 to 14.1 MAX at 20 degrees C.
So ideal voltage would be 13.95V.

That means that charging at the typical 14.5V per battery, is over-voltage by .55V at 20C. And by .75V at 25C! And by even more in summer at 30C... Remember that this means your battery has just 200 to cycles instead of the claimed 500! So 8 months heavy deep cycle use. Instead of 17 or 18 months!

Whats more almost all of these chargers tell you its charged after say 8 hours overnight with a green LED. Well its not! To fully charge, and so fully return all of the sulfates back to the acid, requires 12 to 16 hours minimum in cyclic use. Again MK shows this clearly here: http://www.mkbattery.com/pdf/mktechm.pdf
So they lose more life through sulfation.

MK TECH PDFs
http://www.wheelchairdriver.com/MK0.pdf Ideal tech charge algo...
http://www.wheelchairdriver.com/MK1.pdf ideal charge detail
http://www.wheelchairdriver.com/MK2.pdf AGM and Gel tech sheet and differences
http://www.wheelchairdriver.com/MK3.pdf sell sheet
http://www.wheelchairdriver.com/MK4.pdf sellsheet
http://www.wheelchairdriver.com/MK5.pdf sell sheet
http://www.wheelchairdriver.com/MK-AGM.pdf MK AGM Battery, run away...

http://www.wheelchairdriver.com/odyssey.pdf best lead battery available, and what I use in lead chairs. For fast charge, high current, sport, etc. These cost! Because this low resistance comes from more concentrated acid, and very thin 99.99% pure lead plates. So that impurities dont cause corrosion with stronger acid electrolyte.
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 22 Nov 2018, 20:20

Charts from MK for gel...
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Burgerman
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 26 Nov 2018, 00:27

Burgerman wrote:Again MK shows this clearly here: http://www.mkbattery.com/pdf/mktechm.pdf

Thanks for the graphs and info.
Note that mkbattery.com link above gives a 404.

I got some charge curves back from the Italian charger company that has the relatively lightweight 24v 12a charger. Not very scientific but it looks like the gel curve has about the right voltage, but then does the unwanted higher voltage after CV. The generic gel/AMG (AGM?) curve doesn't have the higher voltage phase, but the CV stage looks too high for gel.

Just out of curiosity I asked if they'd do a custom curve. They said they could for a VAT registered company, in conjunction with their UK dealer, if there was a commitment to buy 50 units. And they also said the 12a charger would not be made any more, so it would have to be 10a or 15a. So I guess I won't try to start a business to sell the perfect 12a 24v charger suitable for travel since it won't exist any more. 15a might melt things with an XLR connector and 10a isn't that much of an advantage over 8a to make it appealing.

I suppose if I got the existing 12a, I could use a diode to lower the voltage of their generic curve and it wouldn't be harmful. Then the float would go down a corresponding amount, but maybe that would be good too.
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 26 Nov 2018, 01:45

Dont buy that. Their CV stage is not constant! It is supposed to be CONSTANT voltage...

And we dont see any mention of the termination point in a time limit sense and they claim its 16% of the charge current which is way too soon. And they dont even get the AGM abbreviation spelling right. It stands for Absorbed Glass Mat separators. That equalization stage is meant for large deep cycle lead storage batteries with WET acid. Not gel. Its designed to mix up the acid by making it gas. Which destroys sealed batteries, and damages gel batteries by making voids in the gel that never heal if you do it regularly. We wont mention that the float voltage for gel is 13.5V at room temp. 13.8 will overcharge it after a few hours. And too high.

You CAN do an accelerated finish, if you stop the CV charge at half the charge current, but unless you know accurately how much was taken out then its inadvisable.
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Re: Power Supply for PowerLab8 v2

Postby flagman1776 » 26 Nov 2018, 03:31

I'll need to upgrade my PSU from 24V / 25A ebay unit to something more powerful once I have the PL8 in hand.
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 26 Nov 2018, 11:28

No rush. Unless you want to charge faster. You can set the PL8 supply section to never exceed your current power supply Amp rating.
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Re: Power Supply for PowerLab8 v2

Postby flagman1776 » 26 Nov 2018, 19:07

Because TravelScoot batteries are so small... just 10 AH... my hour plus charging time is quite acceptable. On the original set up, I did as you suggested & installed Anderson SB50's on the PSU output / Hyperion power feed. So I'd just need the same Anderson Connector to power the new charger.
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 27 Nov 2018, 00:03

I received the PowerLab8 and FUIM3 from revolectrix (£26.51 import tax + Fedex fee). I also got the power supply with EC5 connector and a custom XLR - Banana plug cable I ordered from Coolice. That was everything I needed to connect to my Permobil C500s.

Is there anything on the FUIM3 which indicates which side is up to plug it in to the PL8? I guess I got lucky because it worked when plugged in, or does it matter if it's upside down? Seems like it would physically fit either way.

I downloaded Oracle's free VirtualBox and a Windows 10 iso for a Mac laptop running Mac OS X (10.13) and installed it. I ran the installer for the PL8 v2 software and the FUIM3 usb driver. I set up a USB filter to let the virtual windows talk to the USB port and it connected to the PL8. I played around with the software a bit and got the gel 12a preset to load, then figured out the right sequence of buttons to press and charged at 12a for a few minutes as a test. Seems to work. Thanks Burgerman and everyone for advice and suggestions.

I think I'll get some kind of small wheeled cart, maybe with space for a laptop on top, so the supply and charger can live next to the chair while I'm in bed and be wheeled out for a quick charge when necessary.
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 27 Nov 2018, 00:07

Use the software to charge. And to control the charger. I just dump the charger on my chairs seat next to my bed. And with it my laptop. I keep a power supply under the bed and the cable on it while I am up and about.

I think the only time I press its buttons is to charge my chair or quadcopter/planes inside the van...

Although I wish you luck with that mac! :fencing
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 27 Nov 2018, 00:46

I'll have to try some things to see how it works. Once I'm in bed, I'm pretty much stuck and don't have the strength to lean over or arrange things, so I have to rely on someone else to plug in and start the charge. Laptops are too heavy to be really portable for me, so using my main one probably won't work. I could get a cheap dedicated laptop to sit next to it. I guess it also depends on who is helping me whether I have more confidence that they can press a few buttons, or click something on the screen without needing a guided support session.

I was pressed for time during my test, and couldn't see how to start the charge from the software, so I'll have to spend more time figuring out the software too. I think it did make a graph which I'm looking forward to seeing when I get back to that laptop.
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Re: Power Supply for PowerLab8 v2

Postby Burgerman » 27 Nov 2018, 02:13

A 10 or 11 inch netbook would do.

I am spoiled. I have an infinity edge laptop from dell, its a 12 inch laptop with a 13.3 quad HD screen, and its the lightest thinnest smallest 13 inch laptop made. Its all carbon fiber, and you can pick it up, and swing it about with 2 fingers. Its also got the best screen on any laptop I ever saw. Rich colour, tons of brightness and contrast. And very good wide viewing angle. But it wasn't cheap. Around 1900 pounds... Which isnt great! Its the lighter business version of the dell 13 XPS. But I use it many hours a day for a TV, and everything else when stuck on my bed. So worth it to me.
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 27 Nov 2018, 14:35

jefferso wrote:Is there anything on the FUIM3 which indicates which side is up to plug it in to the PL8? I guess I got lucky because it worked when plugged in, or does it matter if it's upside down? Seems like it would physically fit either way.


I just found the answer to this question. I took a photo of the USB to FUIM3 plugged in to remember which way it worked, and only then noticed the little "TO P.C." "S + G" legend on the top of the PL8, which corresponds to plug hole in the back for the black, red and white wires of the plug.

That laptop seems good. I have a MacBook air, which is pretty good for weight (not carbon-fiber-good, but good for metal), but it's not just the laptop that's too heavy for me, it's also my arms. I have to get everything set up just right so my hands don't start sliding off the keyboard as I type.

I was looking at a new £99 GEO Book, or some old second hand heavy thing since it would just sit next to the charger most of the time.
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Re: Power Supply for PowerLab8 v2

Postby flagman1776 » 28 Nov 2018, 15:33

I hate some of the plugs that take several tries to get right. I put a sticker on the side that goes UP. A white cord I just drew on it with marker but most are dark color.
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Re: Power Supply for PowerLab8 v2

Postby jefferso » 05 Dec 2018, 20:39

Has anyone added an Anderson connector to a Permobil C500? Now that I have a PL8 working at 12A with an XLR plug, I'm eager to try more amps.
I'm thinking I can get some cable and blade connectors with an Anderson SB50 on one end, add them to the right battery posts, and just leave the end hanging out the plastic shell near the lower XLR plug socket. I'd want to mount it securely eventually, but might have to wait to get some more help for that part.

I have some extra 2mm diameter stranded cable, but for 20 or 30A, I'd need more robust cable, correct?
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