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[Burton]

Ok, thinking about adding another charger to my two charger array. As many of you know I currently have 2 RSP-2000-48's trimmed to 56v for 114vDC which happens to be 90% on my bike.

I am getting about 5000w from my RSP + stock chargers in ideal conditions.
The stock charger is giving me 1250w and the stack about 3800w.

With the extra RSP I think I would max out at 6800w with stock chargers, or 5550w from the RSP stack. A 1750w, actual, increase over my current setup for the cost of another RSP charger.


I have some general questions / challenges I need to figure out

1) If I added an RSP 2000 24 to my RSP 2000 48 stack in series would I just add the voltage and current trimming to the 24v charger?
The RSP - 2000 series can trim voltage from 40-115% of the rated output. This means for a 24v unit I should be able to trim from 9.6 - 27.6vDC
But 48+48 = 96 + 9.6 (trimmed 24v charger) = 105.6vDC and the charger won't charge anything less than 80% of the set voltage or in this case 84.48vDC ...

I will need to see what the lowest voltage is for 0-10% battery life and go from there. You can trim the 48's down to as much as 42 with the built in potentiometer or add an external one to trim from the 40-115 range if I recall.


2) I would likely have to add a current trim potentiometer for the RSP - 2000 - 24 unit to make sure I don't trip circuits. Where in the world am I going to put these pots in my current design so they are not easily bumped but are easily accessible? And are there any good solutions for this already which are compact and easy to mount?


3) Will my 60Amp 250V schottky diodes bridging my RSP charger outputs be enough for the stack or should I double stack them?
http://www.mouser.com/ProductDetail/Diodes-Incorporated/SBR60A150CT/?qs=oDfC%252bbpznix4S9PTCizw3w%3D%3D

If I ideal leave a 20% buffer then they should be 52.5*1.2 or 63 amps ... not a EE so will have to figure it out.


4) Voltage sensing circuit will need to be added to get better performance near the max voltages. How would this work with three chargers in series?
Will have to review some of Doctorbass's older replies to make sure I set it up right


5) With more chargers in the stack the size of the container / box to shield them from weather will grow, I will have to revisit my potentials for a weatherproof breathable box for this project. When the new "tank" comes in I can see about fitting these chargers into the tank area by chopping up the old tank and making a new tank to contain the array! ... I think.


I will update my answers to these later if they are not addressed by other users who might provide input in my absence.

[Lecram]

Very interesting project and thanks for sharing!

I am wondering how you can charge at these Amps as the Quick Charge fus is only 30A. Did you replace this fuse with a higher rated one or don't you use the Anderson connector?

[Burton]

I am wondering how you can charge at these Amps as the Quick Charge fus is only 30A. Did you replace this fuse with a higher rated one or don't you use the Anderson connector?

You are welcome, but the complete build isn't done yet which is why I don't have a post indicating "this is how I did it, this is what you need to order etc..."

I don't use the onboard external charging connections. Instead I made connections from my controller's + / - terminals to the Anderson connector and capped off the two on the bike.

I did charge a couple times up to 40 amps through the 30 amp fuse but it blew after a while before I realized what had happened. With the new method I just have to close the contactors (for now that involves turning on stock chargers) then wait about 10 seconds and plug in the external chargers.

I think this is covered in my charging adaptor / update video. I used two 10AGW silicon wires for this.

[Lecram]

Thanks Burton.

What's the max amount of amps you can charge throught the controller connection? Is the charging covered by the BMS than, or isn't that necessary?

[Burton]

Thanks Burton.

What's the max amount of amps you can charge throught the controller connection? Is the charging covered by the BMS than, or isn't that necessary?

The sevcon will limit your "regen braking" amps and you will need to open them up. That said, and I haven't tried this, you might be able to charge through the 30amp on the bike and through the controller.

My sevcon is set to 90 amps right now but Terry said his is set to 400 amps.

The MBB on the 2013 will limit the amps / volts per cell / pack as well. I haven't tested this but I believe it would open the contractor if you try to charge with too many amps.

So far the max amps I have pushed through the controller has only been about 40. After I do a survey of stations local to where I ride for two J1772 connectors I will decide to build another RSP stack or get a elcon stack to supplement it (since they are more weather resistant) and push that up to 82 amps through the controller and 10 through the stock charger.

[Lecram]

Thanks again.

Is it necessary to have a sevcon coding software (as discussed on this forum somewhere else)?

[Burton]

Thanks again.
Is it necessary to have a sevcon coding software (as discussed on this forum somewhere else)?

Might not be necessary if you do the method I suggested. I don't have two charging stacks to make sure it would work though. That is hook one charge up through sevcon and the other to the stock charger.

If this didn't work or isn't desirable then modifying the settings would be necessary if you want to push past stock (I think 40 amps) limitation on the sevcon. If someone who can modify the programming lives close to you then it might be a better option.

If anyone in the DC area who has a 30 amp charger wanted to hook up to confirm this would work let me know. Or, we will just have to wait to see if I build another RSP stack or buy a elcon stack. Or ... someone at zero could confirm it would work

It should be noted this is only an issue on the 2013 bikes. The 2012 and down don't have this problem, and the 2014+ bikes have a higher amp fuse to allow for more amps via the stock Anderson connector.

I should also mention I have no clue how this system would work on an FX as I don't know how close it resembles charging limitations on the S / DS / SR models.

[tommi]

Out of curiosity, what are the charging times going to be? E.g up to 90% and 100%


Sent from my iPhone using Tapatalk

[Burton]

Out of curiosity, what are the charging times going to be? E.g up to 90% and 100%

With my current setup (set to 114vdc for 90% SOC top off) I can push out 40 amps from the RSP's and 10 from the stock chargers in ideal conditions.

As the RSP's get closer to 114 though they taper off on current a bit. This can be corrected with the use of another RSP 24 in series with the two 48's (also in series) and with the addition of voltage sensing circuits. This would also increase the amps from the RSP's to about 50-52 reducing charging slightly since you would be putting out close to 7k total.

I have not let the bike get down below 20% when on the road for charging but it took about an hour and a half to go to 90% last I was charging in the wild. With the additional RSP it could be reduced to about an hour ten minutes.

With two stacks of 2 RSP in series they would allow for 80amps at the RSP side and 10 from stock chargers for 90 amps. Theoretically it would reduce charging from 20 - 90% to 45minutes but would require two 30 amp 200-240v circuits to operate properly.
Two stacks of 3RSP in series would push out 100-105amps in ideal conditions 0_0 adding a stock charger and you are charging at 1.1 - 1.15 C >__<

I will likely keep it under 1C no matter what I end up doing in the long run.

[Doug S]

Stationary they are both set to 57.0 ... when engaging the battery at 50% the top unit is about 52 and the bottom 57 0_0 ... Does this matter at all ? I am still getting 40 amps out to the bike but it worries me the rma unit isn't working as hard as the bottom one.

Hey Burton, sorry for coming to the conversation a little late. It seems to me, if you have two chargers in series, when they're below their current limit they'll put out full voltage -- but that only happens when the battery is fully charged, right? You're not going be able to impress 114V across the battery until it's fully charged. Until then, you'll be up against the current limit of the charging stack, and it's unlikely both of the chargers have exactly the same current limit....they may both be nominally set to 40A, but one's always going to be slightly higher than the other. So you'd expect to see the one with the slightly lower current limit running in CC mode, while the one with the slightly higher current limit runs in CV mode because the other one is keeping the current slightly below its current limit.

I wouldn't worry about it. Seems expected to me.

[Burton]

Zombie thread time.

I will likely be selling this charging stack to help buy my diginow tank charger.

Right now the output is to an Anderson connector (to connect to the bike) and the inputs are to PP45's ... It is set to 114vdc out (which is 90% SOC on my 10.5kW nominal bike)

Message me if interested

[MrDude_1]

Burton,

I did a quick video with some details for you here:

Enjoy!

Doc

Doc,
Sorry to drag up something from a year ago, but are these sense wires correct?
I think I am doing what you're saying, extending the current sense to after the long power cables, but I would like to be sure. Currently I just have my sense wires using the factory meanwell jumpers to the output posts next to them.

[Doctorbass]

Burton,

I did a quick video with some details for you here:

Enjoy!

Doc

Doc,
Sorry to drag up something from a year ago, but are these sense wires correct?
I think I am doing what you're saying, extending the current sense to after the long power cables, but I would like to be sure. Currently I just have my sense wires using the factory meanwell jumpers to the output posts next to them.

The schematic you posted is right!

Doc

[MrDude_1]

The schematic you posted is right!

Doc

Thank you for confirming.
One more related question. Lets say in theory you wanted to raise the voltage of your meanwell slightly past what the voltage pot let you do.
If I were to place a multi turn potentiometer in the middle of one of the sense wires, could I turn it and creep the voltage up a little?
Keeping in mind cap voltages inside, of course... and overall wattage draw.

Do you know of anyone whos tried this? Im searching Endless-sphere right now, but its a hard thing to search for.

edit: ah HA! it actually does work, right up until you slam into the zener diode protection. Apparently the pot limit stops short of what it can do, so that the sense wires can have a couple volts to work with.. and then the diode protection kicks in when the voltage gets too high.

[Doctorbass]

In fact the sense wires can correct up to 0.5V per polarity.. I also already modified the pots of some lab power supply to get higher Volt and it jdoes work most of the time... sometime when you alre Lucky the Contsant Power will kick in and will limit the max output and avoid burning the unit.

Doc