CC/CV chargers

[KauaiMolokai]

Greetings all,
I read postings regularly and I have to thanks everyone here. Some very smart, knowledgeable, experienced folks!

Can anyone/many people tell me of, and point me at, an effective programmable CC/CV cell charger, please. Something I can use to fully charge LIFePO4 280Ah cells, and also other cells with different current/voltage requirements - that I can set, and which automatically goes to CV when cell voltage is met. (Specifically I will be charging Prius gen 2 cells also). Input will be US domestic AC.

Thanks

 

[Prenes4321]

I use

TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display

so far its worked perfectly for me.

 

[KauaiMolokai]

I use

TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display

so far its worked perfectly for me.

Hi Prenes,
Thanks. Exactly the type of advice, and device, I was looking for. I much appreciate it.

John

 

[yabert]

There is ton of hobby chargers available who can charge and monitor single cell to up to 6-8-10 cells.
Some work directly from 120v outlet, some work at 12-24Vdc and are easy to power from a used laptop power supply or other power supply.

I appreciate my Icharger 1010B+ since a decade now, but if I have to choose today, I think those models are nice and affordable:
-ISDT Q8 (dc input to use with any power supply 10-34vdc)
-iSDT D2 AC Power (AC input)

The main advantage of an hobby charger is the flexibility* and the monitoring of a charge or a discharge.
*I regularly charge 4S Lifepo4 cells, 7S NMC cells, 6S NMC cells, single cell and sometime 12V lead acid batt. with my hobby charger.

 

[KauaiMolokai]

There is ton of hobby chargers available who can charge and monitor single cell to up to 6-8-10 cells.
Some work directly from 120v outlet, some work at 12-24Vdc and are easy to power from a used laptop power supply or other power supply.

I appreciate my Icharger 1010B+ since a decade now, but if I have to choose today, I think those models are nice and affordable:
-ISDT Q8 (dc input to use with any power supply 10-34vdc)
-iSDT D2 AC Power (AC input)

The main advantage of an hobby charger is the flexibility* and the monitoring of a charge or a discharge.
*I regularly charge 4S Lifepo4 cells, 7S NMC cells, 6S NMC cells, single cell and sometime 12V lead acid batt. with my hobby charger.

Hi Yabert,

Thanks. Very helpful recommendation. I appreciate you taking the time

Best regards

John

 

[Steve_S]

I use

TekPower TP1540E DC Adjustable Switching Power Supply 15V 40A Digital Display

so far its worked perfectly for me.

I use this exact same model as well, it works as advertised and have had no issues. https://tekpower.us/tp1540e.html
When I received it, it would not run, after opening it to look, I discovered a connector came unplugged during shipping, fixed that and it's been fine.

An FYI: I am presently Top Charging EVE 280's from 3.29V to 3.65 and saturating till <2A drawn. Starting at 37A CC then to CV it takes about 11 hours time for ONE cell. Once the cells for the pack ate Top Charged and they are settled, then connecting them in Parallel and Top Balancing till <2A is taken again and allowed to settle for 12 hours prior to assembly into a Series Pack with BMS. NB: Acceptable cutoff from EVE-280's is 0.05C or 14A

This Bench Supply CAN charge a 12V Pack without issue, as well as a single cell. They have a 30V/30A version ($269) if you want to be able to do a 24V Battery Pack and they have a 60V version too. Thing is they start to get quite pricey the bigger you go, so you want to make sure you have more uses for it than just to charge your cells, to get your money's worth out of it..

 

[KauaiMolokai]

Hi Steve,

Thank you. This is very valuable info coming from you. I've read almost everything you have posted, and there's no doubt you are for real and not just dabbling. I also became good friends with Amy. She good, honest and helpful. I'll buy from her in a heartbeat. Thanks also for the cell charging parameter - I was going to be looking for just that!

What BMS are you using? If it passes muster with you, it's got to be good!

Yeah, I don't have any problem buying tools and equipment. DIY ain't free but no matter how much I spend it's better than paying someone to do it. (with rare exceptions of course).

Call me a cynic but I've found almost everything (or at least all the components) is made in China, regardless of the "made in USA" or "made in Australia" claims. I'll try to track down a source for these Tekpower units, or a Chinese clone.

At this point I'm no further than early contemplation stages of setting up solar systems on a rural property or two I have. Learning as much as possible. I have a couple of Priuses and need to get the HV batteries sorted out/reconditioned/replaced. I found a high voltage power supply which I can use to charge the whole battery to get one car up and running, but this power supply won't help with individual cells.

In my previous life I flew corporate jets all over the world. Many, many stops in deep NE Canada, so I have the utmost respect for you living off grid there! One huge reason why you need reliable equipment! I'm in Hawaii mostly, so I know a little about corrosion! (and don't need low temp cutoff protection hahaha).

Let me know if I can do anything for you.

Thanks again

John

 

[HRTKD]

Can anyone/many people tell me of, and point me at, an effective programmable CC/CV cell charger, please. Something I can use to fully charge LIFePO4 280Ah cells, and also other cells with different current/voltage requirements - that I can set, and which automatically goes to CV when cell voltage is met. (Specifically I will be charging Prius gen 2 cells also). Input will be US domestic AC.

I think you're making it more complicated than it needs to be. "Programmable" is a whole new level of complexity and cost. To charge the type of batteries we're dealing with doesn't require programming. Turn the voltage knob to 3.65 and connect it up. When it hits that voltage threshold the amps goes to zero. This is for most benchtop power supplies. My power supply was $75 and worked just fine. It's been used for a couple other non-battery projects since then, so I am satisfied with what I got.

 

[KauaiMolokai]

Hi HRTKD,

Thanks.
Good points. I do better with KISS equipment.
How about achieving the "saturation" where you want to keep low amps flowing at 3.65 V, rather than just total cut off at 3.65? Of course I get that doing this step might not be absolutely necessary and as such an unnecessary complication.
What power supply do you use?

 

[HRTKD]

Hi HRTKD,

Thanks.
Good points. I do better with KISS equipment.
How about achieving the "saturation" where you want to keep low amps flowing at 3.65 V, rather than just total cut off at 3.65? Of course I get that doing this step might not be absolutely necessary and as such an unnecessary complication.
What power supply do you use?

Are you talking about a float charge?

Here is the power supply I used.

Amazon.com

 

[KauaiMolokai]

Hi Jim,

Thanks. That looks like a good power supply, and if you've used it and it works well for you that's a great recommendation.

I don't know if it's called a float charge or a saturation charge with LiFePO4 cells, and I have very limited experience with any cells/batteries other that old lead acid batteries so I'm the last one to claim any expertise, but I understand that if you charge LiFePO4 cells to 3.65 V and then cut off charging, and let them sit for 24 hours or so they will stabilize at about 3.50 V I'm guessing the Prius cells I'll be working with will do something similar. And I know lead acid does too. (different voltages though obviously). But I also understand that if you keep a float charge on lead acids slowly that stabilizing point creeps higher over an extended period of weeks. And I've heard that if you maintain 3.65 V on LiFePO4s that the current they accept will tail off to less than 2 amps after some number of hours, thus ensuring you then have them topped charged "to the max". I'm more than happy to learn if any of these understandings are wrong.

Thanks again

John

 

[HRTKD]

Most LiFePO4 charge profiles will not maintain a voltage that high. My solar charge controller may charge to 14.4 initially, but then it will drop down to something like 13.6. Checkout this document in the Resources section of the forum:

LiFePO4 Voltage Settings guide for BMS, Chargers and Loads

All the voltage settings in the BMS, Loads and Chargers can be daunting to figure out. This paper attempts to explain the various settings, how they relate to each other and how to choose them. Click on the orange '' button above for the...

diysolarforum.com

 

[KauaiMolokai]

Hi Jim,

Great document and resource, thanks!

John