New PowerMax Lithium Series Converter/Chargers

[Sabre36]

Better than Progressive Dynamics and WFCO going right to 14.60 that will virtually always cause a DIY battery BMS to disconnect.

Not convinced the adjustable voltage affects more than just the boost voltage. Have read posts the 13.2 and 13.6 remain fixed.

I wish it was power factor corrected.

We've had multiple customers destroy LFP batteries withProgressive dynamics chargers.14.6V 24/7/365.....D'oh

 

[time2roll]

Got to know the specs. The word "lithium" is still a mystery for both users and manufacturers.

 

[Browneye]

My Orion 'smart' charger arrived today. ?
Oooh boy...another BT app. LOL

 

[Browneye]

I have to admit, the Victron Smart Charger is really slick. Easy to setup with a nice BT interface, you can easily set all the parameters, and it's rock solid. Works perfectly. Turns on when the engine does, charges to bulk then backs off to float - set values to whatever you want.

Now I need to do a deep discharge and test it all again. Let's go camping.

 

[JimmyM]

If I hadn't already bought the Powermax I think I might prefer the Victron Blue Smart IP22 charger. It's "only" 30A, but has all the lithium settings the MPPT's have for lithium charging via bluetooth.
But alas, here we are.

 

[rickst29]

We've had multiple customers destroy LFP batteries withProgressive dynamics chargers.14.6V 24/7/365.....D'oh

Yep, 14.6V all the time is a very bad choice. But with a Lithium-Capable PD, (rather than a Lithium-ONLY model), you can (and I have) just set the DP switches for GEL. That prevents anti-sulfation cycles completely. (In PD, they are only at 14.6V and not as "deadly" for LFP as high-voltage anti-sulfation cycles - but why not prevent them completely?)

From there, however, PD converters have the optional charge-wizard pendant: Unlike the Powermax models, you can simply press the button to re-invoke "Bulk" mode. I like 'em (and have installed several for my customers, as well as myself), but only when set for GEL.

 

[JimmyM]

I got the new converter today.
The label shows model: PM3-55LKX and output voltage 13.6
It arrived set in the fixed voltage mode with 14.600V measured. Yup to the millivolt.
Below are my test results:
Out of box:
Fixed Voltage: 14.600V (3.65 V/Cell)
3-stage Boost: 14.600V (3.65 V/Cell) (dropped to 14.584 at 30 minutes)
Dropped from Boost to Absorption at 30min.
3-stage Absorption: 13.598V (3.4 V/Cell)
Didn't wait for drop to storage mode
3-stage Storage: Didn't wait for the switch, but literature states 13.2V (3.3 V/Cell)

Adjusted fixed mode to 14.0V
Fixed Voltage: 13.998V (3.5 V/cell)
3-stage Boost: 13.998V (3.5 V/cell),(dropped to 13.996 at 30 minutes)
Dropped from Boost to Absorption at 30min.
3-stage Absorption: 13.008V (3.25 V/cell)
Didn't wait for drop to storage mode
3-stage Storage: calculated to 12.65V (3.16 V/Cell)

A simple 1V offset would have resulted in Absorption = 12.998V.
A linear adjustment calculates to 13.038V
But the measured 13.008 lies very close to the 1V offset by 0.010V and from the calculated linear value by 0.030.
These are only 100ths of a volt. So who cares?

For absorption, 13.6V (3.4 V/cell) for a few hours would be fine.
For Storage, 13.2V (3.30 V/cell) would be great
But to get those values, you need 14.6V for 30 min. Not sure if that 30 min is after the battery reaches 14.6V or it's just a fixed 30 minutes. That will trip the BMS over and over.

If you adjust to 14.2V Boost, you get the below voltages

14.2V Boost: 3.55 V/cell. A little high, but it only happens very infrequently and would be good for balancing.
13.23V Absorption: 3.31 V/Cell. This is a great voltage for floating
12.84V Storage: (3.21 V/Cell). A little on the low side for use (~20-30% SOC), but with the converter running, the battery SOC is irrelevant.

I'm going to set 14.2V tonight and wait until morning to check the storage voltage.

 

[Browneye]

14.2 to 13.2 would be pretty good. If the pack actually reaches 14.2volts for full charge.
12-something is worthless.

I setup two charge profiles for my main SCC, one low voltage for storage and one with normal to high for active usage.

For storage I want to maintain about 70% SOC.

Orion set for 13.6 absorb and 13.4 float. I only want it to charge if the battery is down. It has a minimum 1 hour absorption stage. Holding a higher voltage isn’t very desirable. If that’s too low I could adjust up to 13.8.
Every time you start the engine the charge cycle starts over. ?

 

[JimmyM]

14.2 to 13.2 would be pretty good. If the pack actually reaches 14.2volts for full charge.
12-something is worthless.

I setup two charge profiles for my main SCC, one low voltage for storage and one with normal to high for active usage.

For storage I want to maintain about 70% SOC.

Orion set for 13.6 absorb and 13.4 float. I only want it to charge if the battery is down. It has a minimum 1 hour absorption stage. Holding a higher voltage isn’t very desirable. If that’s too low I could adjust up to 13.8.
Every time you start the engine the charge cycle starts over. ?

My situation is mostly plugged in waiting for the next trip. Then plugged in at the camp ground. Before my 2 boondocking trips, I'll power cycle the converter to get into the boost mode to be full for the trip.
12.84V would just prevent the pack from going dead.

I don't have an Orion DC-DC charger.

I'm cracking open that PM4 this weekend.

 

[JimmyM]

It's been about 10 hours and the converter is still putting out 13.196 volts. The manual for the PM3-xxLK doesn't state how long it will take to drop to the storage mode. However, the manual for the PM3 based converter replacement section says it should drop down after about 12 hours.
Powermax could definitely raise their game with respect to documentation.

 

[triplethreat]

It's been about 10 hours and the converter is still putting out 13.196 volts. The manual for the PM3-xxLK doesn't state how long it will take to drop to the storage mode. However, the manual for the PM3 based converter replacement section says it should drop down after about 12 hours.
Powermax could definitely raise their game with respect to documentation.

I really had high hopes for the PowerMax converter/chargers if I find out that I need one after trying my existing WFCO 9855 OEM charger on the new LFP battery. After reading and following this thread.........not so much.

 

[Browneye]

13.2 is a good float charge. What's the battery charge level? Is it showing 13.2 on the bms?
That should maintain you at about 90%.

 

[JimmyM]

13.2 is a good float charge. What's the battery charge level? Is it showing 13.2 on the bms?
That should maintain you at about 90%.

Don't have the cells or BMS yet. But 13.2V (3.3 V/cell) isn't 90%. It's closer to 40%. 3.45 V/cell is 90%, But staying at that voltage is too high for long periods I've been told here.
I've got the lid off the PM3-55LK. It looks different than the one you showed, but it too has a VR2.
Maybe I'll just void my warranty and start dicking around with the voltages on the VR1 pot and see if I can make a switch.
I want that functioning PM3-55LKL Lithium Series. That thing should come preset for 14.4V Boost & 13.4V Float and have 2 pots to adjust the 2. How this wasn't obvious to the designers, I'll never know

 

[JimmyM]

Also, it has an ES7P003FGTF micro controller on it. It's not like it's a PIC or Atmel that I can dump the code and sort through things.
But it may be that the pot VR1 is read by the uC to adjust voltages instead of it being a simple feedback pot to the SMPS controller.

 

[Browneye]

You're certainly more technical than I. Not familiar with any of that stuff. ?

 

[sshibly]

As a fixed voltage power source, buying a PowerMax 55 is simply a waste of $$$.
As mentioned before, a similar power source can bought new for much less.
I found that if my batts are halfway down (100ah 12v LFEs), I can zap for 40 mins or so and be done.

Just John mentioned an egg style timer for this, peace of mind, connect to shore power, reach over to Mr Egg and wind it and forget about it.

Wow, 14 page, Chris, now you are resident PowerMax eggspert

 

[JimmyM]

I just did some measuring and some math on my PM4-60. By adding a single resistor with a switch to the voltage sampling divider, I can jump from 13.4V to 14.2V.
Manual boost mode!
Measured voltage are:
No resistor: 13.406V <-Set with pot
With resistor: 14.216V

With that same resistor:
No resistor: 13.201V <-Set with pot
With resistor: 14.108V

Maintain and float for as long as I want at 13.4V (or whatever I set it to), then close a switch with a resistor and I get 14.2 (or 14.4 or whatever I calculate the value of that resistor to)

 

[JimmyM]

Wow, 14 page, Chris, now you are resident PowerMax eggspert

Ha! I see what you did there

 

[Browneye]

As a fixed voltage power source, buying a PowerMax 55 is simply a waste of $$$.
>snip

Agreed. $180 door stop. LOL
The 2-stage charging at 14.6 always pops one cell up over 3.65 and bms shuts down charging. One of them is always going to get there before the others. Completely unusable.

And I'm afraid to set CV too high should I forget to turn the thing off when the pack is full. It would just sit there and burn them.
I have it set to 13.8V for now, turn it off when the pack gets there or close. Re-balancing the cells keeps them equal up to there, but trying to push those last millivolts pushes one over the top. I can get to 14.4 now but no more. And that's really pushing it, equalize is running on at least one or more cells, and that's just not very strong with the Overkill JBD.

13.6V CV might be better, I may try it there. It's just a little low for balancing, but might be fine for 'zapping'. It wouldn't kill the pack to sit at 3.4/cell for a time either. It settles to about 3.35V.
Programmed charging with my SCC does a nice job maintaining the pack - only using AC power and the Powermax when the pack is way discharged.

Or just order out the Means Well charger.
This one will support loads as well as charge, 43A:

NPB-750-12 - MEAN WELL - TRC Electronics

Order MEAN WELL NPB-750-12 battery chargers on-line or call today for exceptional customer service. TRC is the USA stocking headquarters of MEAN WELL NPB-750-12 Battery Chargers. NPB-750-12 is ready to ship today.

www.trcelectronics.com

 

[time2roll]

Agreed. $180 door stop. LOL
The 2-stage charging at 14.6 always pops one cell up over 3.65 and bms shuts down charging. One of them is always going to get there before the others. Completely unusable.

Battleborn and some others must allow higher cell voltages as the 14.6 is the recommended maximum charging voltage.
From what I read 14.6 will not shut down these drop in type batteries.

The PowerMax is apparently fine for those that just want to plug and play.

 

[Browneye]

Battleborn and some others must allow higher cell voltages as the 14.6 is the recommended maximum charging voltage.
From what I read 14.6 will not shut down these drop in type batteries.

The PowerMax is apparently fine for those that just want to plug and play.

And elsewhere here recently, someone was commenting about charging above 3.65V per cell without permanent damage to them.
That BB uses different cells has always been a contention that their recommendations aren't applicable for our 'beautiful blue prismatic' cells as they have been described. LOL.

If this is the case the BMS parameter could be set higher, another 10mv or so, and let the charger peak them up past 3.65V. I dunno, I'm just a hack amateur without funds to throw at experiments. [shrug]
Others have cooked their batteries from charging too high.

As has been said over and over, with these flat voltage readings throughout the charge and discharge profile of these cells, we get enough capacity and longevity staying within the rather narrow voltage levels recommended. Or, 'good enough'. ?

 

[JimmyM]

Just got off the phone with Graham at PowerMax. He recommended the same thing as a few here. Get it charged, then shut it off.
But I described the PM4 modification I made for voltage selection.

He said he'll accommodate the swap of the PM3-55LKL for the PM-55LK or the return of them both. Great guy to work with.

 

[JimmyM]

I've modified my converter with an external switch to select 2 different voltages. I also ran 12V from the converter to the switch panel to power an LED to show which mode is selected. The DPDT slide switch I used doesn't stick out beyond the little panel. So it can't be switched mistakenly.
Those voltages result in 3.3 V/cell and 3.55 V/cell

 

[triplethreat]

Very nice job Sir! So what did the resistance values end up being for the 14.2 volt and for the 13.2 volts?

 

[Browneye]

That is way cool.
You're using the fixed output then? But can switch it manually for charge or float?