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^ Not sure I understand: '183V rebound down', '187V no rebound'? What are we talking about here?

Basically, if I'm understanding the difference between the "A" and "B" model correctly, the CC + CV model is closer to what you'd want in a charger, you'd just get that one and not worry about return policies.

You want to be able to set an upper voltage threshold suitable for the pack (or particular circumstances - maybe sometimes you want 180V, another time you want 172.8V) and be assured the power supply won't breach that - and do it in a controlled way, a way that it's designed for. That's the CC + CV "B" model. I don't know exactly how the other one handles the transition at max user-set output voltage - but it's not what the CC+CV model is, otherwise, there wouldn't be a CC+CV model. My guess is that it's not a very 'elegant' affair...
I just meant depending on the termination type. 187V CCCV charger would mean if it "terminates" by just holding the 187V open circuit hence it would be a 187V CCCV charger. 183V with a rebound down would be if it terminates by sensing when the current dropped below the output knobs setting. If that is the case then it would terminate when leaving the CC region at 183V at the full amps hence the LTO chemistry would rebound down over the next few hours to lower than 183V to probably somewhere around 180V. I didn't see anything in the datasheets that definitively makes me think one or the other is more likely. As far as the better fit I just meant most are trying to stay in the 2.0V-2.5V range to stay on the flat part of the LTO chemistry which would be a good fit for if it terminates at 183V since 187V is 2.6V per cell where the LTO slope starts to get steep (not awful but not flat either).

As far as the output knob while it does alter current and voltage, it's really based on the current. The knob all the way would be the 1.75A and the know all the way down at 50% is .8875A. This makes the voltage differential that the power supply is tracking all the way up change but it isn't about the end state it's about how many amps are flowing in the CC region. These are LED power supplies so lowering the current would change the brightness of the LED lights. I definately don't know of power supply that essentially lets you program when to switch from CC to CV other than the Powerlabs or IChargers and they are essentially just middle men that still need a power supply or other power source.
 

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Chicago & Detroit
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This thread is wonderful. I made a Simple Cycler grid charger that @snikrepretep designed. It uses 2 Mean Well 100V CC supplies, and the code he made monitors the voltage and controls the unit. @ davismltc modified the monitoring circuit so it can read the high voltage battery more accurately; I'm sure its accuracy can be made better. Is it possible this charger with updated parts and code can be used to stop charging at 180V; or 182, or whatever?

Simple Cycler post #187

Simple Cycler Voltage Fix Post #5, 6
 

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Linsight Designer
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If you're trying to recharge a lithium pack in very little time, I recommend getting a Lambda Gen. They're often available on eBay... I purchased one last month (300 volts, 11 amps) for under $100 shipped (using eBay's "Best Offer" option). You'll of course need 240 volt mains to run a supply that large. Fun fact: You can easily modify the 240 volt three phase Lambda Gen units to run on residential (split single phase) mains.

Keep in mind that with lithium you'll want to monitor each cell in the stack... otherwise overcharging lithium (even LTO) isn't nearly as forgiving as NiMH.
 

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Discussion Starter #46
If you're trying to recharge a lithium pack in very little time, I recommend getting a Lambda Gen. They're often available on eBay... I purchased one last month (300 volts, 11 amps) for under $100 shipped (using eBay's "Best Offer" option). You'll of course need 240 volt mains to run a supply that large. Fun fact: You can easily modify the 240 volt three phase Lambda Gen units to run on residential (split single phase) mains.

Keep in mind that with lithium you'll want to monitor each cell in the stack... otherwise overcharging lithium (even LTO) isn't nearly as forgiving as NiMH.
Got a model number? I'm seeing Lambda Gen300-11 on ebay for no less than $699... are you saying someone took a best offer of 10% of the listing price?
 

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The eBay world of used test equipment is a strange one indeed. It definitely favors those who approach it with research of different manufacturers product lines, forum posts about unique features or fatal flaws, common failure modes and their fixability, creative searches to find gear not appearing because of mispellings, ability to discern between "not functional" gear improperly tested and something actually broken, the tolerance for ending up with an occasional boat anchor, and a bucket list rather than an immediate need. Most sellers are surplus dealers who have paid very little and will settle for a low price (which is still profitable) if it has been sitting in their kitchen for months without any interest. The high prices are basically for corporate buyers who need to replace old junk yesterday.
 

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Linsight Designer
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Basically what Sean said... I just wait for people who have no idea what they're selling to list equipment. When it doesn't sell in a week, I typically offer to purchase the item for very little, noting that the seller doesn't need to offer a warranty and can sell the item as-is. Since they know nothing about it, and since these units often appear broken (but are not), many sellers are willing to part with the unknown item for very little. Even when these units are actually broken, they are painfully simple inside and are VERY easy to fix. In fact, I've never purchased a broken unit that took more than a few hours to fix. Sometimes the internal fuses are broken. If you buy a broken unit and can't get it to work, send it to me and I'll repair it for peanuts.

FYI: MY "holy grail" unit is the 200-16.5, but the 300-11, 300-8, etc are great, too.
 

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I've started building my portable Zivan 3kw 72 Cell LTO OBDIIC&C controlled charger.
I'm building the prototype on a plywood board and it will be transportable so can be used on any of my cars.
I don't want to carry it round permanently attached due to the weight 5kg or so.
It's quite powerful and should charge my pack up from 10% to about 90% SOC in one hour.
That makes it useful for rest/meal stops on journeys if you have an electrical hookup.

I have installed a 50A Anderson DC connector on my pack that comes out of the IPU (red cable)
and allows the charger to sit on the back shelf when charging.
The Zivan puts out a fair bit of heat so you don't want it hidden away really.

It's great for demisting/defrosting/warming the car in the winter.
Just turn it on an hour before you want to leave!
Battery will be charged and warm and so will the passenger compartment! LOL

86731


For this test version I will probably mount a dedicated OBDIIC&C CAN on the board.
It will have an OBDII port and the LTO BMS boards will simply plug into it.

It will use standard 16A blue mains caravan hook up connectors for the main power in.
It has a 12v 2A meanwell supply for the BMS boards and OBDIIC&C.

It has a solid state logic level operated 20A mains relay to control the charger.
The Zivan charger is also currently adjusted to a maximum of 2.5V per cell (180V) so whatever happen it won't go above this. (We can tweak this)

The OBDIIC&C will monitor cell voltages etc and cut the charger relay if anything goes out of spec.

We will have to think about temperature monitoring, and probably add a standalone
DS18B20 I2C temp sensor to one of the batteries as we don't have any temperature info
from the car (BCM) old OEM sensors when it's off.

The OBDIIC&C can talk to one of these I2C sensor and gives us an accurate temperature.
We might need some fan cooling of batteries when charging at 20A for an hour.
We shall see. :unsure:


Obviously this is all early days proof of concept.
I'm now waiting for parts to arrive.
 
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