575W 12V Server Power Supply issue

[Spacey]

Ok so I bought two of these:

http://www.rc-monster.com/forum/showthread.php?t=27554&highlight=power+supply

And the conversion went really well, but using my i1010B+ charger I can still only get 4amps for an 8Cell 33V Lipo pack charge. The problem is that if I go any higher the charger says that the input voltage is too low? From the output of the HP Server power supply it only drops from 12.4v no load to 12.37v under as much load as I can give the charger?

There are two terminals for each of the positive and negative outputs, I have only connected wire to one so maybe you need both of the terminals for double the power? Maybe the cable going from the power supply to the charger is too long at 1 meter using standard 13amp 240V cable....hmm 13amp 240V cable is ok at 240v but maybe it is too thin for 12v use?

Or maybe it's the crocodile clips I am using for contact of the Lipo plugs?

They were only £15 each so well worth the money, any thoughts?

Oh I just remembered I am using the 12V Battery i.e car battery terminal to the charger rather than the little plug.

 

[Spacey]

The white arrows are where I did not wire up a lead, this is not a pic of my actual charger.

 

[neptronix]

Why are you using clips for the lipo plugs, and not the bullet connectors the lipos came with? break out the soldering iron and make some real connections. Throw those clips away. They are dangerous and it is only a matter of time before you short them.

Use at least 12-14 gauge wires for the power input to the iCharger.. looks like that's what you have already though.

A turnigy watt meter can be used to track down this problem, but i have a feeling that the issue lies in the connectors you're using.

You should be able to output about 6 amps to the battery pack ( you hit an iCharger 1010b+'s watt limitation around there. )

 

[Spacey]

The pic of the charger is not my set up, running out of connectors until my order comes in from Hobby King. But yes I will wire up some proper cables

 

[FMB42]

I believe this unit (DPS-600PB HP 575W Power Supply) is capable of operating with 110 or 220 input voltage. If so, do you have it switched to the proper input voltage?

 

[Spacey]

Interesting thought, I am in UK 240V and bought on UK Ebay so figured it must be set for this, will check though.

In other news my i1010B+ was set for balance on CV Charge and since changing that setting failed to balance my cells on the dodgy pack even though balance charge was chosen and just kept going. Luckily I was monitoring the charge and caught the battery as my runaway cell charged to 4.32v

 

[liveforphysics]

10awg wire.

Connect to both terminals.

Go into settings in your iCharger and change the "low input voltage set-point" to be 10v.

Problems solved.

 

[Hillhater]

I have a similar Dell DPS 500CB PSU which is a great unit (41A @ 12.6v).
Anyone tempted to use these PSUs need to be aware of the need to jumper the control pins in order to power up the outputs ( the white wires as seen in the photo above) .. but be aware , each PSU model seems to have different pin configurations ( mine has 24 pins not the 12 on Spacey's unit)
Most of these have been figured out on the RC forums , together with some mods to up the output to 15v i seem to remember

 

[Metallover]

It should sound like a hairdryer if you have your jumper pins set to right.

 

[Spacey]

Interesting thought, I am in UK 240V and bought on UK Ebay so figured it must be set for this, will check though.

In other news my i1010B+ was set for balance on CV Charge and since changing that setting failed to balance my cells on the dodgy pack even though balance charge was chosen and just kept going. Luckily I was monitoring the charge and caught the battery as my runaway cell charged to 4.32v

I figured out why my i1010B+ didn't balance charge. You need to reset the charger i.e turn it off then back on....otherwise it goes funny if you charge a pack then charge another. I reset the charger and its back to normal.

I will solder on some 10AWG cable with proper connectors tomorrow.

So what are people setting there Cell Logger's to give the LVC alarm at? I have mine set for 3.5v and I charge to 4.15v

 

[auraslip]

8s * 4.2v * 4a = 134 watts from a 575 watt psu...

Since you didn't wire up both connectors, perhaps this power supply has two parallel 12v 250w rails? But you said it only sags to 12.37v under load, so that doesn't like the problem.

You're seeing no sag at the psu, but the wires and the alligator clips could be problematic, but I wouldn't think they cause such a large drop. What does the voltage look like from the i1010's perspective and how does that compare to the multimeter reading?

I think I read somewhere that low voltages can affect balance accuracy with some chargers, and I've found this to be true with my imax b8.


It's cool that you got these for so cheap and locally too!
I've been drooling over a $30 48v 3000w hp server PSU for bulk charging my 16s ping.... just got find out how high the voltage can be adjusted and limit the current on it...

 

[snellemin]

That is my pic up there. There are more mods done to that power supply. The peeps on rcgroups even sell kits to run dual psu's for 24V. You could make a 48V setup if needed for dirt cheap.

This is what I'm pulling from the PSU