5S Charger

[RyanM923]

As of now, I'm using a 4s charger that is made for a 14.8V nominal pack that uses 3.7V cells (charges to 16.8V)...looking to get a little closer to topping off my 5S lifepo4 pack with a real 5S charger that's made for it, but there's a "but". I need it to only charge to 18V, I don't want to push the cells past 3.6V per. Everything I have found charges to 18.25V...

Does anyone know of a place to grab a 5S lifepo4 charger that only charges to 18V?

 

[Sunder]

This one will:

https://hobbyking.com/en_us/imax-b6-ac-v2-charger-discharger-1-6-cells-genuine-au-plug.html

If you already have a DC power supply:

https://hobbyking.com/en_us/imax-b6-50w-5a-charger-discharger-1-6-cells-genuine.html

They both terminate charge at 3.60v per cell. http://www.skyrc.com/download/IMAX_B6_Manual.pdf.8080e517a1de969503f0992b5b056363

That said, why so sensitive? Most LiFePo4 have a fairly wide tolerance. Thundersky for example will tolerate over charge up to 4.0v: http://en.winston-battery.com/index.php/products/power-battery

I doubt terminating a charge at 3.65 instead, is going to have ANY impact on longevity.

 

[RyanM923]

I doubt terminating a charge at 3.65 instead, is going to have ANY impact on longevity.

You have a good point, this is just for testing purposes anyways, to measure voltage sag compared to charging to 16.8V, using 300/500/750/1000A loads. Just need something to top the pack off.

 

[dogman dan]

I agree, 3.5 v is full for lifepo4, but typically battery makers spec to overcharge lifepo4 because its so dang tolerant of it. I've seen it set to charge past 3.8v.

So if you truly want to undercharge, 17v is your target.

yes,, to charge full, the imax b6 is a good affordable utility charger, though slow.

But you could also top off cells one by one, with a 5v wall wart from a phone charger.

 

[RyanM923]

Been doing some more looking, and I cannot for the life of me find a large 16V lifepo4 charger...something at least 10A. Am I missing something or is there just nothing really out there for this application? Only thing I can find is some alibaba people that do a lot of different chargers.

 

[Sunder]

Try something like this:

http://m.ebay.com/itm/LED-Access-Switching-Power-Supply-18V-4A-6A-10A-20A-Power-Transformer-Adapter-/222044455268?nav=SEARCH&varId=520906188655

There's a $10 one as well, but its only 8a sustained, 10a burst.

 

[Sunder]

Wait... 16v? 5S LiFe is 3.6 x 5 = 18v

16v / 5S = 3.2v, the nominal voltage, not the charge voltagr.

 

[999zip999]

17.5v works for me do monitor. At lease 17v or 3.4v each.

 

[RyanM923]

Wait... 16v? 5S LiFe is 3.6 x 5 = 18v

16v / 5S = 3.2v, the nominal voltage, not the charge voltagr.

16V nominal pack I meant, if it wasn't clear. 18.25V charging voltage.

 

[Hillhater]

Just get a $25 Meanwell 350, or clone, from Ebay..the 0-24v adjustable version .
Set it to whatever voltage you want. Charge at 15A , with Cc/CV profile.