question

esimmers avatar image
esimmers asked

Need Lithium battery LiFePO4 charge settings for Blue Smart IP65 charger

Has anyone found a custom setting for the Blue Smart charger that works best with LiFePO4 batteries?

I want to charge three different LiFePO4 batteries I own with my Blue Smart IP65 12-Volt 15 amp battery charger. The battery specifications all call for charging at 14.4-14.6 volts (typical for LiFePO4 batteries). But the manual for the charger says the absorb voltage of the charger is 14.2 volts for "Li-ION" batteries (must be for some other lithium batteries). I'm really surprised that this charger doesn't have a setting for LiFePO4 batteries since they are in such widespread use.

Has anyone found a custom setting (including float and storage values) for the Blue Smart charger that works best with LiFePO4 batteries?

Thanks

Ed


battery chargingLithium Battery
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

3 Answers
matt1309 avatar image
matt1309 answered ·

Hi @esimmers

I would say that the Li-ion settings here are fine for LiFePO4.

14.6v is 3.65 per cell. That's the absolute max i would charge a lifepo4 cell to, personally i think that's excessive just shortening the life of battery.

I personally set my absorption voltages to 3.45v (tbf i am overly cautious though).

It's way less stress on the battery and you lose approx less than 1% SoC by doing so.

The default li-ion setting of 14.2 is 3.55v per cell. That's perfectly fine. The capacity you're losing using 14.2v vs 14.6 is going to be even smaller when using LiFePO4 due to their really steep charging curve when above 3.43v ish.

And honestly probably far better for the longevity of the cells by having them absorption at that slightly lower voltage rather than the absolute max the cells can handle.


Float setting seems to be 13.5 which is 3.375v per cell, a little conservative but that's literally what I use for my setup (I have 48v 16cell pack so float 54v).


Edit: The above is assuming I'm looking at the right manual:

https://www.victronenergy.com/upload/documents/Blue_Smart_IP65_Charger_manual_230V/13527-Blue_Smart_IP65_Charger-pdf-en.pdf

2 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

esimmers avatar image esimmers commented ·

Thanks, matt1309,

YesWhat you say makes sense. And you were looking at the right manual for the Blue Smart IP65 12-Volt 15 amp battery charger with 14.2V absorption, 13.5V float and 13.5V storage.

What's interesting is that SOK batteries (one of my 3 batteries) recommends the Blue Smart charger but said this when I asked which charge profile to use: "Victron LI-ION is NOT for lifepo4 battery, it's for another type lithium battery. Choose the Victron NORMAL mode would be good enough."

SOK's advice is hard to understand given that the NORMAL absorption voltage is 14.7, float is 13.8, storage is 13.5, and there's a 16.5 volt reconditioning phase included.



0 Likes 0 ·
matt1309 avatar image matt1309 esimmers commented ·
Hi @esimmers


That's odd. I'd maybe double check with SoK just to be sure but I agree Normal looks ok I suppose 14.4/4 being 3.6v for absorption. Float 13.8/4 being 3.45 also fine.

However you're right definitely make sure you never enable the recondition mode if you choose normal, 4.05v per cell would not be good for the battery.


The victron manual does mention LiFePO4 (next to Li-ion on page 3) so maybe a it's a newer revised manual that SoK isn't aware of. Might just be worth clarifying with them. But as long as reconditioning isn't enabled I think Normal or Li-ion voltages are ok. I would personally go with the lower Li-ion ones but see what SoK say. Don't want to choose the wrong one and void any warranty you have.

0 Likes 0 ·
Justin Cook avatar image
Justin Cook answered ·

Victron's default LFP charge settings are for Victron LFP batteries, with bulk/absorption at 14.2v. For other brands of LFP batteries that want/need to see 14.4v (or other), just open the charger settings in the app, enable "expert mode", and change the charging parameters as necessary.

screenshot-2023-08-10-10-30-38-210.jpg


1691688862928.png (280.9 KiB)
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

esimmers avatar image
esimmers answered ·

Thanks. All good info. I used your information to get up a custom LiFePO4 charge profile with conservative settings. Ed

2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.