High rate of charge on small Lead acid batteries - Meanwell Charger

[OnTheRoadAgain]

Hello,
I just received a Meanwell PB-300P-12 battery charger and I just wanted to tell others about the way it charges batteries.
I looked at a number of different chargers and settled on this one, but I admit I did gloss over the recommended battery range it is designed for.
Had I pad better attention, I would have preferred a charger better suited for a wider range of batteries such as 5Ah - 200Ah.
However, the Continous Output Current says 12.5Amps, yet I see 20Amps continuous anytime I connect a discharged battery....so it will be an effective charger for my completed LiFePO4 100Ah pack and even for my 272Ah LiFePO4 pack (albeit a bit longer to charge)

So the intent of this post is to help people new to solar power and battery charging to choose the right charger for themselves in case they do a forum search on chargers for LiFePO4 batteries.

Meanwell PB-300P-12 Datasheet
https://www.meanwell.com/productPdf.aspx?i=22#1

In the datasheet it does say output range 60-100Ah That means mean it is suitable for batteries between 60Ah and 100Ah which is suitable for my 100Ah LiFePO4 battery, and most batteries at least 60Ah but not smaller batteries like my 8 Ah scooter batteries or an ebike battery.
I honestly glossed over this important specification before ordering.

Specifically, it applies a 2.5C rate of charge to a 8Ah small motorcycle battery and that is too much for a small battery
When you connect the meanwell charger, it immediately begins charging at 20Amps

The result is that smaller batteries (less than 60Ah) will gas and get warmer than they should
The voltage can be adjusted, but not the current. So while you can adjust the charging and topping voltage slightly, it will still charge at 20Amps.

For a large 100Ah Lithium battery this would be ok, but this charger is not suitable for batteries under 60Ah.

I just wanted to pass this on as this charger has been mentioned in this forum more than once and it's easy to gloss over that fact if you're
new to all this or not taking the time to carefully read all the specifications.............guilty.

 

[snoobler]

Going a layer deeper:

FLA/AGM/GEL batteries all have a recommended charge rate typically between 0.1 and 0.3C. It varies by manufacturer and type, but this is why the MW recommends 60-200Ah.

LFP tends to be 0.5 to 1.0C.

Note 6:
This is MW's suggested range. Please consult your battery manufacturer for their suggestions about maximum charging current limitation

Note that with the 13-14.7V adjustable range, this charger can still be used on small batteries. You just sneak up on the topping voltage. Start at 13.2V. Once current drops to near 0.01C, 13.6V. Once current drops to 0.01C, 13.8V. Once current drops to 0.01C, back to a float voltage, 13.2-13.6V depending on battery.

If you want to monitor it like a crazy person, you can just incrementally increase the volts until you see the current you want.

Even high currents won't produce gassing at the lower voltages.

Step 1 in selecting a battery charger: What is the acceptable charge current range for my battery?
Step 2: Go find a charger that produces the acceptable charge current.

 

[OnTheRoadAgain]

Good points Mr. Snoobler.

I already ordered yet another LiFePO4 charger. lol

The Meanwell becomes my home base AC charger and a (just ordered today) dedicated 10A (max) LiFePO4 AC charger just became my "travel" (vehicle) Plug in LiFePO4 charger. Once my LiFePO4 batteries actually arrive and I can build my packs, I'll set up my vehicle controller to charge LiFePO4's because right now they're still charging the only batteries I have at the moment, Lead Acid batteries.