Configuring a Meanwell 84V charger

[Kingfish]

Greetings –
I just need a sanity check as I wire up my new Meanwells to create an 84V 13A charger.

Proposed Meanwell wiring

Meanwell84V_charger.jpg (30.25 KiB) Viewed 836 times

• VAC comes in on the right.
• Meanwell SP-320-48 Qty-2 in parallel
• Meanwell S-350-27 in series, taking the +V from the 320s and routing it to the –V of the 350
• Use the +V from the 350 and the GND to charge the battery array via the BMS.
• The –V from the 350 would essentially not be used.
• 320-48s are trimmed to +54V, and the 350-27 is trimmed to +30V.

Does this look correct?

Thanks, KF

[andreym]

Greetings –
I just need a sanity check as I wire up my new Meanwells to create an 84V 13A charger.

Meanwell84V_charger.jpg

• VAC comes in on the right.
• Meanwell SP-320-48 Qty-2 in parallel
• Meanwell S-350-27 in series, taking the +V from the 320s and routing it to the –V of the 350
• Use the +V from the 350 and the GND to charge the battery array via the BMS.
• The –V from the 350 would essentially not be used.
• 320-48s are trimmed to +54V, and the 350-27 is trimmed to +30V.

Does this look correct?

Thanks, KF

It looks correct becides you should take -VDC from lower sp-320-48 supply -V.
As soon as sp-320-48 are hiccup type, be sure that your S-350-27 are true CC\CV.
In that case it will work fine.
One more thing you could worry is higher than 100% CC current of s-350-27
check it out - if the current would be too high you might want to trim it down a bit by cutting\resoldering one of shunts inside (if you have 3 you can just cut one, if you have one you will heed to re-solder it with similar but higher resistance)

[GGoodrum]

Andrey is right, the negative pack connection goes to the DC V- on the bottom unit. Is this for a 20s LiPo setup?

Gary

[Kingfish]

Corrected!

Meanwell84V_charger-corrected.jpg (30.34 KiB) Viewed 785 times

Gary: Yes, 20S LiPo
Understood; makes sense. This look correct? (kinda messy, sorry)

Many thanks! KF

[mwkeefer]

Still not right for all 3 in series - I assume your going to turn down the voltage on all 3 so they max at 83.x when in series?

It should be crossed again on the last unit, the ground i mean.. at one end (bottom of stack) pull GND (-) off as an output line then connect the + positive of that meanwell on the bottom to the GND (-) of the one above it, then the one above it gets it's + connected to the final unit's negative and you pull the + postivive charging lead off the last.

So you end up with all 3 in series and Ground coming from the bottom unit, VCC or Positive coming from the top unit.

The current will limit to approx 125% of whatever the S-350-27 would output so you need to do:

1.) Set desired (lowest) output voltage from the S-350-27
2.) Fan mod - replace thermistor with resistor so fan on S-350 comes on always
3.) Adjust current output via shunts or resistor R33 on the S-350-27

That should get you working reliably and quickly

Hope it helps!
-Mike

[Kingfish]

Still not right for all 3 in series - I assume your going to turn down the voltage on all 3 so they max at 83.x when in series?
<snip>

Mike, it's two 48V in parallel + one 27V in series, voltages bumped to equal 84V max. Currents are matched with the S-350 attempting CC.

However - I plan to use Goodrum's CC charger device so that should be managed.

Clear as mud?

[mwkeefer]

2 in LPT and then Series with the 27v, yep diagram is right.

Even with the charge controller, I'd mod the 27v for the fan and proper current before connecting them all together to a pack.

-Mike

[GGoodrum]

Mike is right, I'd do the current mod on the S-350-27. The Charge Controller doesn't kick in until the cells are nearly full. The current limit mod is a 5 minute task. You simply tack on a 2K resistor to R33, assuming it is in the same place as for most of these.

-- Gary

[Kingfish]

Man, I'm nearly on the way to Radio Shack, can you tell me exactly what do I need?

2K at what wattage?
ES-Link??

[GGoodrum]

Man, I'm nearly on the way to Radio Shack, can you tell me exactly what do I need?

2K at what wattage?
ES-Link??

1/4W or 1/2W

[Kingfish]

Right; I'm away!
Thanks gentlemen

[Kingfish]

With S-350-27, I applied the mods to the Thermistor (1k POT in parallel), and 2k ohm resistor in parallel to R33.

I don’t notice buzzing per se. When the fan comes on it drags the voltage down to 13V and the voltage trim POT cannot overcome this. Once the fan shuts off then I can trim to my hearts’ delight.

My workaround is to remove the top cover altogether and be done with the silly fan

The rest of the assembly went well.

Have I missed something? I thought I bought a 350W PSU at rated voltage. What gives?
~KF