Do I have the wrong charger?

[g__0]

Was recommended this charger over on the reddit OverkillSolar sub. https://expertpower.us/products/epc1220-20a-1

I'm trying to understand if this charger matches Will's recommendations in the Sticky thread. It doesn't appear to say what the Float voltage is in the specifications and I don't see WHEN it switches to Float voltage either. It doesn't appear to be configurable (no dip switches or anything).

Can anyone educate me on whether this particular charger is appropriate for my 12v 200ah lifepo4 pack? I'm using the overkill BMS.

 

[snoobler]

14.4V = 3.6V/cell - good.
13.6V float = 3.4V/cell - good.

It will likely switch to float around 2A. Not great, but not a big deal. Finding an off-the shelf charger capable of the correct tail current is essentially impossible.

If Overkill themselves recommended it, I'd take it without question. If I were looking for a 20A 4S LFP charger, I would consider this one based on the available information.

For your 200Ah pack, the moment you hit 14.4V, you're almost fully charged. The correct tail current for your pack is about 10A in lieu of specific battery data.

 

[g__0]

Overkill themselves didn't recommend it just another person on the sub.

Think I'm missing something basic in terms of the charging - when you say it switches to float around 2a, can you explain?

 

[snoobler]

Charger works as follows:

20A input until 14.4V
Hold 14.4V by tapering current as battery fills at a slower rate.
Once current tapers to 2A while holding 14.4V, charge terminated.
Provide sufficient current to maintain 13.6V.


Vref = 14.4V
Iref = 20A
Ico = 2A

The float portion is not shown.

 

[John Frum]

Tail current refers to terminating the charge before current flow gets to 0.
Optimal tail current for lifepo4 is probably .05 c
For a 200 amp hou r battery thats 10 amps.
I wouldn't worry to much about 2 to 2.5 amps though.

 

[g__0]

Thanks all, I get it now.

 

[DJSmiley]

Another option is the Meanwell PB 360P-12 power supply. Same price range, slightly higher current (24A)

TRC Electronics - Power Supplies and LED Drivers

Order MEAN WELL PB-360P-12 battery chargers on-line or call today for exceptional customer service. TRC is the USA stocking headquarters of MEAN WELL PB-360P-12 Battery Chargers. PB-360P-12 is ready to ship today.

www.trcelectronics.com

https://www.meanwell.com/Upload/PDF/PB-360/PB-360-SPEC.PDF

Also it allows adjusting boost and float voltages, so you can set them to 14.2V/13.4V as per Will's recommended settings for long-life

Personally, I prefer Meanwell, since they have a good track record in providing reliable powersupplies for industrial purposes.

(For a huge bank they also offer a PB-600 and PB-1000, 40 and 60A chargers, which can be set to 2 or 3-stage for use with Lithium)

PB-600-MEAN WELL Switching Power Supply Manufacturer

MEAN WELL is one of the world's few standard power supply mainly professional manufacturers, covering 0.5 to 25,600W products are widely used in industrial control, medical and other fields, in line with international safety certification, short delivery of spot inventory.

www.meanwell.com

PB-1000-MEAN WELL Switching Power Supply Manufacturer

MEAN WELL is one of the world's few standard power supply mainly professional manufacturers, covering 0.5 to 25,600W products are widely used in industrial control, medical and other fields, in line with international safety certification, short delivery of spot inventory.

www.meanwell.com