PIP-2424 Settings for Lithium Charging

Hey all,

First time posting. I finally have enough recycled 18650 cells to build a starterpack and start pulling the trigger on some hardware.
From what I can tell, the PIP-2424LV-MSD (Canada 120V version) is the best bang for buck and people have had good success using them.
However, they are not designed to charge lithium batteries and some setup is involved in getting them to run the 18650 packs safely.

Is it possible to use their software to get reliable settings for charging these packs?


Thanks for the advice!

Matt

Yes it is. But you must set your top charge to 4.1V/cell max. You don't want to carry too far into the top end of LiIons without starting to cut back current.

Korishan said:

Yes it is. But you must set your top charge to 4.1V/cell max. You don't want to carry too far into the top end of LiIons without starting to cut back current.

Click to expand...

Thanks Korishan, this is what I have read but it is nice to get confirmation

Can someone clarify the bulk and float voltage settings and how they relate to the constant current charging and max charge voltage of lithium cells?
I am confused because some people are saying they set the values to the same voltage (eg. 4.1V) and others set them to different values. I have also heard of people talking about setting the max time for the float charge. Will the charger not simply charge to the max voltage (4.1V = bulk or float?) and then shutoff when the charge current is below a threshold?

The only safe way to charge lithiums is with a balance charger, lithiums have a habbit of going out of balance especially when being fast charged. Most BMS on lithium batteries can't balance a pack fast enough.With any none balancecharger, eithersolar or AC powered, if they can't monitor each cells voltage, your are going have to rely on overall voltage.

Your pack has to be in perfect balance, I use active balancers on my 4s lifepo4 battery pack to make sure it stays in balance, no matter what. With li-ion 18650 its even more important to stay in balance.

I been using the ecoworthy 20 amp mppt to charge my pack, its not lithium capable, but I can adjust the absorb/float voltage. When I had a 3s 11.1 volt li-ion pack, I was told to set the ecoworthy absorb to 12.6 volts, but the lowest it went was 13.1 volts. I ran with that, even in full sunlight I was charging at less that 5 amps from my 240 watt panel, which was too slow for me, I decided tochange the absorb voltage to 14.4 volts, now I was getting 15 amps from the panel.In other words to get best performance your going to have to find a voltage that will fast charge your battery, too low and the battery will only slow charge at very low amps. As far as float if you set it low enough, it will give the battery less than 1 amp or even 0amps. You have to find the voltage sweetspot that will work on your battery pack.

But for safety, use asetup like on my system,an overvoltage relay disconnects the solar panel when the battery reaches a set voltage. For instance if you have a 3s 11.1 volt battery and you don't want the cells to go past 4.1 volts, set the overvoltage relay to disconnect the panel at 12.3 volts. The Battery BMS should only be the final safety feature if everything else fails. If the BMS on the battery ever trips while on the solar controller, the controller will try to forcefully charge the battery, this will cause voltage surges, these surges will destroy any equipment connected to the battery pack. The overvoltage relays are extremely reliable I been using them since last year connected 24/7. Before I started using the relays I had to adjust the absorb voltage several times every day, now I go months without adjusting anything.

The most important thing to fast charge with solar, is your battery has to be in perfect balance, otherwise the battery BMS will always trip when fast charging and your battery will never get a full charge.

Picture of relay I use on my 4s lifepo4 (set to disconnect at 14.4 volts), but you can use on li-ion, the cutoff voltage can be adjusted up to 40 volts, other overvoltage relays are available that can go up to 99 volts.

jonyjoe505 said:

The only safe way to charge lithiums is with a balance charger

Click to expand...

Yes, I will be installing the Batrium hardware for balance charging.

---

Regardless of balance charging, I am still curious about using the PIP software to charge the lithium batteries.

Refer to my previous post.

It will work fine. Set float and bulk to same voltage or like 0.1-0.2V part from each other. Setting them same generally is the way most people do it.
If you plan on 4.1V per cell then 4.1x number of cells in series and you are good to go.

Just beware of that the first top run you charge them up that you manually monitor them or have the Batrium hooked up with an emergency disconnect in case one or multiple packs run away upwards when getting fully charged.

daromer said:

It will work fine. Set float and bulk to same voltage or like 0.1-0.2V part from each other. Setting them same generally is the way most people do it.
If you plan on 4.1V per cell then 4.1x number of cells in series and you are good to go.

Just beware of that the first top run you charge them up that you manually monitor them or have the Batrium hooked up with an emergency disconnect in case one or multiple packs run away upwards when getting fully charged.

Click to expand...

Perfect! Thanks for the info! Can't wait to start generating some clean energy.

Just sent "Peggy" a money transfer for the PIP-2424LV-MSD and will beeagerly waiting for the email confirmation for the order.

I've been looking at this inverter over the Split Phase one as I am only looking for 120V @ 60Hz How have you found this inverter for use?

Thanks

The PIP is what I use. It's a CCCV charger and is the same if you watch hbpowerwall's youtube videos. There's no complication on if it runs on Lithium or not. I don't think there's even an equalization option on mine, if I recall. So I simply switch it from one of the preset modes to the user mode, set the bulk and float voltage to be the same. That's it. It'll charge until it reaches 28.5V on mine at 60A and then once it reaches 28.5V it will decrease the amps down until the battery can maintain a steady 28.5V.

I was debating about the split-phase but the one thing that kills me is that the idle power consumption. 1.2kw is what it uses per day. It takes about 800W out of my batteries. It was a huge problem when I had only 3.5kwh, because with 80% duty cycle and 90% inverter efficiency, I was left with only about 1.8kwh of actual power. But now with 10kwh it's much more manageable. But to have two units for the split phase would be a waste of energy unless I needed to run something large.

Otherwise my PIP has been working well since Feb. I ran everything from PC, TV, fridge to a 5000BTU A/C with no issues. My plan for this winter is a 12000BTU heat pump.

bumping this thread as I'm having issues with my 48v pip inverter.
max voltage it will apply to my batts is 58.4 and i've calculated with my 14s pack it should be charged at 58.8
is this 0.4v difference going to matter at all ? should i drop down to 13s instead ?

edit: after a day of charging, it looks like it doesn't matter. but i'd be interested to hear if anyone think it's an issue.

58.4 is healthier/easier on the cells. At 58.8, that's 4.2V on each cell. With 58.4, that's 4.17 per cell. A bit better. If you want 100% max power capacity, then that's fine. If you want longevity of the cells, then 4.1 (57.4V) would be better.

And no, .4V difference won't make much of a difference. The usable capacity difference is negligible.

Thanks Korishan. As I suspected but great that you can confirm it for me.
Tested today, and batteries did charge although not much (overcast day) so it doesn't seem to make any difference.

Good to know!