Combining charger and power supply for higher voltage 82 v.

[999zip999]

I have read if I understand correct I can combine a 58.9volt 5a. Li-on charger and a 21.4-28.8v meanwell power supply If my charger is isolated. Here a pic of my charger and three screws connecting a heat sink to some fets and the case.

 

[amberwolf]

Did you have a question? Or are you just showing us the project?

 

[dnmun]

yes, you can adjust the charger and power supply voltages so that the sum reaches the final voltage for the pack.

you can use the maximum current adjustment on the charger to set the charging current. the power supply will provide the same amount of current as the charger since they are in series so there is no need for a current feedback hack to the power supply.

if you try to push more current than the limit of the power supply then it may go into hiccups depending on which series of meanwell or knockoff that you are using.

 

[999zip999]

Sorry is my charger isolated so I can use a meanwell 21.6v- 28.8v or can I use two HP600 power supplies series for 25.2volt ? The HP 600 are isolated.
A.W. I was working on getting my phone to transfur pics I had to get out the old G.E. camera. New age can't keep up.

 

[999zip999]

So no worry if charger is isolated or not ?
Power supplies HP 600 12.6v 40amp. x 2.
Just simply put them in series for 82v or so at 5amp. It's the fact that it will charge at 5amp and not higher or can I treak the charger for more amps with out blowing it up. 24s A123 20ah pack no bms. I just use 15ah out of it at the most.

 

[amberwolf]

If everything is isolated, then you can series them. If they're not, then anything not isolated would short across other non-isolated units.

To see what I mean, just draw it out as boxes with ac input connections and dc output connections, parallel all the inputs and series all teh outputs, and then draw in teh connection between ground or neutral on the input and the - of the output on any non-isolated unit, and you can see the shorting path.

Isolation just means that the input side is not connected at all to the output side.

Not isolated usually means the ground of the output side is connected to the ground or neutral of the input side.

If you use ohms and/or continuity test on an unplugged unpowered charger you can verify if any input side wires connect to any output side wires.


Often but not always you can break the connection inside between input and output, and make a non-isolated unit into an isolated one.

 

[999zip999]

Ok one probe in the neg. output and touch all three input and no continuity. Pos. output and touched all three output prongs with switch on and off no continunity. Still scared like a little girl. Don't want to blow a working 16s charger.

 

[999zip999]

I see fets attached with screws to an aluminum plate screwed to the case. This part doesn't look isolated.

 

[999zip999]

Did I do the test right ? I'm I good to go.

 

[999zip999]

Ok I have a three prong AC plug and only two wires are connected the hot and neutral and the third prong is not connected to anything inside the charger.
So I'm good to go ?
This is ground isolated ?

 

[nutnspecial]

http://endless-sphere.com/forums/viewtopic.php?f=14&t=69295
Hey man, I haven't tried isolating any grounds yet, but this thread contains a similar query of mine and appropriate recent links. Notice what Luke says here. And I can vouch that the mw hrp's are isolated.

Li-on charger and a 21.4-28.8v meanwell power supply If my charger is isolated

I think the charger is isolated. Those heatsinks are just connected to be sturdy and for cooling, I don't think for grounding purposes.

Sorry not a be-all-end-all answer, but I think you're ok. Just be careful, but if something is not isolated, I think they usually just don't run/shut off, and that's only if they touch.

Try it and then check continuity between cases to simulate them touching!

 

[dnmun]

all SMPS have the output isolated from the input. by definition.

 

[999zip999]

Good dnmun so it is isolated. Yes ?
Just confusing especially the part of the charger in series limiting the power supply 40 amps to the charger limit of 5 amp. Plus I guess the charger should be last in series on the positive end ?

 

[dnmun]

it does not make any difference if the charger is first in the series or the last. you will only need a 5A power supply if the charger is a 5A charger.

 

[999zip999]

I only have 3 HP 600 12.6v 40amp 550 watt isolated power supplies to play with and the 58.9v 5a charger.
So I did the test correctly for isolation with probe in the neg output and continuity with the two AC input ?
I wish I could get a yes or no on if it's isolated.

 

[dnmun]

you had never mentioned you are using a server power supply. that is not a true independent power supply because it is built as a component of the server.

i thought you were talking about a meanwell power supply which is different from these server power supplies.

 

[999zip999]

I bought them isolated for running Hyperion 1420. I used them at 25.2 volt for that charger. Can I use them with the Li~on charger 58.9v that trying to get an answer if it is also isolated.

 

[cal3thousand]

If everything is isolated, then you can series them. If they're not, then anything not isolated would short across other non-isolated units.

To see what I mean, just draw it out as boxes with ac input connections and dc output connections, parallel all the inputs and series all teh outputs, and then draw in teh connection between ground or neutral on the input and the - of the output on any non-isolated unit, and you can see the shorting path.

Isolation just means that the input side is not connected at all to the output side.

Not isolated usually means the ground of the output side is connected to the ground or neutral of the input side.

If you use ohms and/or continuity test on an unplugged unpowered charger you can verify if any input side wires connect to any output side wires.


Often but not always you can break the connection inside between input and output, and make a non-isolated unit into an isolated one.

This is a very good explanation AW!

 

[999zip999]

I put the negative probe in the neg output and the other probe in the three input prongs and no continuity. Is this the correct method. For the Li~on 58.6v charger ?

 

[999zip999]

Dnmun told me the 58.6v 5a Li~on charger is isolated.
The HP 600 power supplies are isolated 12.6v 40a yes I bought them that way to be used for 24v input for rc charger (1420 that died ). The cases are isolated in case they touch.
Can I series all these for 83.6 volts and the Li~on charger will handle the cc~cv for charging. at 5amps.

 

[999zip999]

So checked the three HP 600 power supplies for isolated ground with a continuity test. The probe in the neg output and the input ground. Two were isolated and the third one wasn't ? I hope this the test for isolation ? Can someone confirm please.

 

[dnmun]

isolation is where the input is isolated from the output. the ground is separate from the input except for 120V AC in the US the ground is the same conductor as the common wire so the ground wire is connected to the common so it is not isolated from the ground on the input but the output negative should not be connected to the input ground unless the designer decided to connect the input ground to the output negative. i think this is how these server supplies are wired.

if the input is 240V then there is no common used and the ground is separated from the input but it can still be connected to the output negative.

 

[999zip999]

What is the proper test ?

 

[dnmun]

just check continuity.