250W 36 or 42V charger/balancer for 100$

Doctorbass

Doctorbass

100 GW
Joined
Apr 8, 2007
Messages
7,501
Location
Quebec, Canada East
Nup, you've got me Doc.

How is a 10 x 5v supply a charger? It's just a 5v supply, it doesn't have a lithium charging profile or balance.
 
Mark_A_W said:
Nup, you've got me Doc.

How is a 10 x 5v supply a charger? It's just a 5v supply, it doesn't have a lithium charging profile or balance.
Click to expand...

A charger IS a power supply. Precisly a power supply with a current limit and a voltage limit.

A charger is JUST "like you said" a power supply with limits...

The charging profile of li-ion is CC-CV power supply mode! so these dc-dc device ARE CC-CV.. so THEY fit to charge any li-ion cells

These "power supply" are step down DC-DC converter wich mean that it is a device that take higher voltage like 48V and decrease it to low voltage with more current like 5V....


BUT what make this idea brilliant is that this is a 5V adjustable one! from 3V to 6.5V.. . and can stak in serie any number of them!!! you can put 100 of them in serie .. no prob. for a 360V pack for exemple for a ev car

That mean you can set their output (with a potentiommeter (1$) to charge any voltage from 3V to 6.5V... ideally 3.6V for A123 and 4.2V for lipo or other li-ion cells...

the 48V power supply is to supply all their input. but you can use any from 36 to 72V

The dc-dc are isolated between in and out so no short circuit could happen if paralleling input and makig output in serie.

Everybody SHOULD consider this idea as a simple and cheap and rapid way to charge battery pack with balancing feature!

I know what i mean!... keep in mind that idea

see my project:http://endless-sphere.com/forums/viewtopic.php?f=14&t=2824

Doc
 
The Doc is right.

The best I've been able to find for an adjustable power supply at 5V is $7.95 (in volumes above 25 units) for this 65W product:

12922.jpg


http://www.powersupplydepot.com/listitems.asp?dept=3&main=1

...this does appear to be a good deal. As long as the charger addresses just one cell it only needs to know to slow to a stop it's current as the voltage rises.

This product he's presented is even cheaper and looks good. 25 watts is probably a better charge rate for the smaller cells than the 13 amps (65W) of the other one.

Plus they look really compact... so using them would be easier. (they might even be built into the bike itself somehow)
 
Hey Doc! Does this mean U can use, say, an Astroflight 112D which can put out 72 volts, as the Power supply to these little DC'DC converters to charge Lithium batts?? I sounds like it to me!
David (other Doc)
 
docnjoj said:
Hey Doc! Does this mean U can use, say, an Astroflight 112D which can put out 72 volts, as the Power supply to these little DC'DC converters to charge Lithium batts?? I sounds like it to me!
David (other Doc)
Click to expand...


Probably.. but usually, RC charger like mine (Megapower) ned to measure at least a minimum voltage on their output (like the voltage of a empty battery) to activate... mayve if you put it in Ni-Cad mode it will not need that.. try that... try to see if your charger can output voltage if you dont plug any cell... if it can, then the ball is in your group!
:wink:

mine can output 12s at 4.2V (so it's 50V)

Usually these DC-DC can accept between 34 to 75V

Doc
 
Also, what could make it portable and compack is to fix all dc-dc on the top of the charger alluminium case for dissipating the heat. all dc dc are around 85% efficient so 250W output would mean (1.15 x 250)-250 =37.5W of heat and this case should work fine for that brecause the power supply would be used half the power su the other half not used would accept the 37.5W and use 100% of the cooling.

now who want to charge at 250W and balance their at the same time for 100$ :mrgreen:

My project is close to that exept that i'll charge to 1000W for 350$ total investment.

Doc
 
Doctorbass said:
Mark_A_W said:
Nup, you've got me Doc.

How is a 10 x 5v supply a charger? It's just a 5v supply, it doesn't have a lithium charging profile or balance.
Click to expand...

A charger IS a power supply. Precisly a power supply with a current limit and a voltage limit.

A charger is JUST "like you said" a power supply with limits...

The charging profile of li-ion is CC-CV power supply mode! so these dc-dc device ARE CC-CV.. so THEY fit to charge any li-ion cells

These "power supply" are step down DC-DC converter wich mean that it is a device that take higher voltage like 48V and decrease it to low voltage with more current like 5V....


BUT what make this idea brilliant is that this is a 5V adjustable one! from 3V to 6.5V.. . and can stak in serie any number of them!!! you can put 100 of them in serie .. no prob. for a 360V pack for exemple for a ev car

That mean you can set their output (with a potentiommeter (1$) to charge any voltage from 3V to 6.5V... ideally 3.6V for A123 and 4.2V for lipo or other li-ion cells...

the 48V power supply is to supply all their input. but you can use any from 36 to 72V

The dc-dc are isolated between in and out so no short circuit could happen if paralleling input and makig output in serie.

Everybody SHOULD consider this idea as a simple and cheap and rapid way to charge battery pack with balancing feature!

I know what i mean!... keep in mind that idea

see my project:http://endless-sphere.com/forums/viewtopic.php?f=14&t=2824

Doc
Click to expand...

Ahh, ok, it's adjustable voltage.

But it still doesn't have a two stage lithium style charging profile. I'm not sure you need that 2 stage charging for an a123 cell.
 
PDF?

Do you know of a technical pdf file for these?

I prefer to proceed with an indepth analysis of the technical stuff before I completely buy in on the idea. :?

(though it looks very good)
 
Mark_A_W said:
Doctorbass said:
Mark_A_W said:
Nup, you've got me Doc.

How is a 10 x 5v supply a charger? It's just a 5v supply, it doesn't have a lithium charging profile or balance.
Click to expand...

A charger IS a power supply. Precisly a power supply with a current limit and a voltage limit.

A charger is JUST "like you said" a power supply with limits...

The charging profile of li-ion is CC-CV power supply mode! so these dc-dc device ARE CC-CV.. so THEY fit to charge any li-ion cells

These "power supply" are step down DC-DC converter wich mean that it is a device that take higher voltage like 48V and decrease it to low voltage with more current like 5V....


BUT what make this idea brilliant is that this is a 5V adjustable one! from 3V to 6.5V.. . and can stak in serie any number of them!!! you can put 100 of them in serie .. no prob. for a 360V pack for exemple for a ev car

That mean you can set their output (with a potentiommeter (1$) to charge any voltage from 3V to 6.5V... ideally 3.6V for A123 and 4.2V for lipo or other li-ion cells...

the 48V power supply is to supply all their input. but you can use any from 36 to 72V

The dc-dc are isolated between in and out so no short circuit could happen if paralleling input and makig output in serie.

Everybody SHOULD consider this idea as a simple and cheap and rapid way to charge battery pack with balancing feature!

I know what i mean!... keep in mind that idea

see my project:http://endless-sphere.com/forums/viewtopic.php?f=14&t=2824

Doc
Click to expand...

Ahh, ok, it's adjustable voltage.

But it still doesn't have a two stage lithium style charging profile. I'm not sure you need that 2 stage charging for an a123 cell.
Click to expand...

What you need to know is that generally, when talking about two stage charging we doo not talk about cc-cv. two stage is a two current level charging... not a Constant Current - Constant Voltage charger.

These "two stages" are cheaper charger that have not the perfect circuitry to perfectly stabilyze voltage and current (CC and CV). Often it is like two fixed current power supply with a circuit that switch from one to the next at a given threshold. They are used because they have better performance than if they could have a single normal not cc-cv power supply that charge at a simple voltage and that can not balance cells.. using two power supply with two current mode, when voltage of the pack reach a level where cells could become unbalanced, it switch to low current mode to let them balance with or without a small a circuit that balance cell on the cell pack. That method take alot of time cause the low current second stage can sometime take few hours! Soneil Charger i think are like that.. they are made to charge overnight.. not fast chargeor burst charge for many ride in the same day...

With the method of single cell charger(one charger per string) using DC-DC i am suggesting, there is no need of external circuit that balance the cell... because the cell will never get unbalance while charging, cause each parallel string charger have a fixed limit... 3.600 or 4.200V... the comon two stages charger can only charge all cells string in serie.. so it can not balance efficiently the cell while charging

But the DC-DC do that! and alot faster!

And any li-ion including A123 NEED CC-CV to charge fast and to avoud overvolting them at the end of the charge.

Doc
 
safe said:
PDF?

Do you know of a technical pdf file for these?

I prefer to proceed with an indepth analysis of the technical stuff before I completely buy in on the idea. :?

(though it looks very good)
Click to expand...


Safe, check for the 6C 21 in that PDF:http://www.btcpower.com/PDF/Datasheets/LP/C Series/6C DS ver2.PDF

:mrgreen:

cheaper and more powerfull and acurate than voltfreak for cheaper!!!! :wink:


The 6C-01 model would be great too to be able to charge from a single car lighter plug or 12 battery!!!.. but from now it does'nt exist on ebay... maybe a price quote could be interesting!

Doc
 
Trim?

It looks like you trim the chip by adding a pot and just connecting it across a couple of the pins. If that's all there is to it that's very easy.

So let me get this straight...

These "should" reduce the current as the voltage of the cell rises to the target value right?

This just seems so much easier than buying a MOSFET and a comparator and trying to manage the current on your own. (like if you tried to use a computer power supply)
 
Doc do you think i could just buy the dc to dc 5 v and use my 48 volts soneil charger instead of buying another power supply
 
safe said:
Trim?

It looks like you trim the chip by adding a pot and just connecting it across a couple of the pins. If that's all there is to it that's very easy.

So let me get this straight...

These "should" reduce the current as the voltage of the cell rises to the target value right?

This just seems so much easier than buying a MOSFET and a comparator and trying to manage the current on your own. (like if you tried to use a computer power supply)
Click to expand...

These DC-DC are voltage controlled and current limited so the voltage will NEVER exceed the pre-seted value. that is perfect! and the current will never exceed the limit protection of the dc-dc.

That is as simple as you mentioned..

Doc
 
slayer said:
Doc do you think i could just buy the dc to dc 5 v and use my 48 volts soneil charger instead of buying another power supply
Click to expand...


Slayer.. Yes your soneil should work great to supply these.

Doc
 
Doctorbass said:
Also, what could make it portable and compack is to fix all dc-dc on the top of the charger alluminium case for dissipating the heat. all dc dc are around 85% efficient so 250W output would mean (1.15 x 250)-250 =37.5W of heat and this case should work fine for that brecause the power supply would be used half the power su the other half not used would accept the 37.5W and use 100% of the cooling.

now who want to charge at 250W and balance their at the same time for 100$ :mrgreen:

My project is close to that exept that i'll charge to 1000W for 350$ total investment.

Doc
Click to expand...


Thanks a lot DOC

so with that do you think I won't need any extruded aluminium for my Dc-Dc tyco modules then?

I have a sheet of aluminum but with out the fins i wonder if that would be enough?


and secondly my max current is 20 amps would still have to worry about the current adjustment?? (sorry i wish i was more e smarter)

thanks again you r the MAN

efreak
 
do i connect 10 modules or 20 modules of the tyco type QHW100F1 66W AND OUT DC 3.3 20 AMP IN: DC 36-75 2.4AMPS

What amperage at the input d i need 20 amps at 48 volt or is that too much ??

efreak
 
efreak said:
do i connect 10 modules or 20 modules of the tyco type QHW100F1 66W AND OUT DC 3.3 20 AMP IN: DC 36-75 2.4AMPS

What amperage at the input d i need 20 amps at 48 volt or is that too much ??

efreak
Click to expand...



be sure to get at least 110% of the max tyou will need.

DC-DC are around 80% efficient so if you need 80W out per DC-DC, you will have 100W in.. so choose 110W for safety margin.

you will never have too much watt until your budget can buy :mrgreen:

Doc
 
so 1200 or 1500 watt at 20 amps 48 volt then Doc?


thanks

efreak
 
in reading over the this thread got me thinking! can I not use 2 power supplies say 48 volts with like 15 amps or so for 5 modules .

split the input into two power supplies
may be easier to find a suitable power supply?

efreak
 
or this any good?
http://cgi.ebay.com/Argus-Pathfinde...ameZWDVWQQrdZ1QQcmdZViewItem#ebayphotohosting

You are bidding on one (1) Argus Technologies Pathfinder 10kW Rectifier. It is new and in box! The box has never been opened! We have a total of twenty (20) in stock, ALL NEW AND READY TO BE POWERED ON! Contact us if you would like to purchase more than one. (We also have the cabinets for them if you are from a business and want them organized).

-Part Number/Model Number: 010-547-20
-Item available for Local Pick-up

- Here is a PDF file from the internet about this item.

http://www.alpha-group.ru/files/File/rectifiers-systems-telecommunications/pathfinder10000.pdf










Shipping and handling
 
efreak that thing has way more power than you need and it requires a high rated 3 phase supply to run it.

The power supplies doc pointed out in the first post of this thread have isolated outputs and can therefore be combined in parallel to supply more amps. They come in 500W versions too.
 
so if i parallel 3 x 10 amps 500 watt power supplies should i expect it to deliver 25 amps for 10 modules needing 2.5 amps ??

efreak
 
or three of these http://cgi.ebay.com/400W-48V-8-3A-...VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

now only if i can be assured this is going to operate at around 24 -25 amps if paralled x3 (to supply 10 x modules at 48 volt to get the required out put 3.6 )
and not try to adjust down to 8.3 amps like flip was mentioning i think.

ideally would be nice to get 5 power supplies to feed 2 modules each 48 volt 5 amps to get 10 modules fed on 5 ps
 
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