Charging batteries with external charger

[Yoshi]

Hi,

I am attempting to charge two lithium batteries in parallel with an external Noco 5 amp charger. When I hook them up, the charger lights green (fully charged?) and I do not see any increase in current with my smart shunt (should I ). Is the charger too small?

Is it charging or am I missing something.

The batteries are in the RV and wired as they should be.

Thank you,

 

[DonTom]

Is the charger too small?

The lith battery voltage is above the charger voltage so it will not work. You need to get a charger designed for

Lifepo4 lith batteries:​

-Don- Auburn, CA

 

[Yoshi]

The lith battery voltage is above the charger voltage so it will not work. You need to get a charger designed for

Lifepo4 lith batteries:​

Hi,

It does has a lithium setting. It's lit up in the top photo. I just thought it would charge, but just at a very slow rate. I once (before I installed the batteries) charged them indiviually and it seemed to work.

 

[Mark_K5LXP]

The spec sheet says it can:

LITHIUM
Used for 12V lithium-ion batteries (including lithium iron phosphate). Only for batteries with Battery Management Systems (BMS).

Something I'd try is "force mode", which should (briefly) bypass voltage detection and start a charge cycle.

Mark B.
Albuquerque, NM

 

[Yoshi]

Edit..hmm, last battery I charged with it was my lawn mower battery. Maybe it is still stuck in LA mode.

I'm not sure how to "force it".

I have to do the same thing (force it on) with my stock lead acid WFCO battery charger. Thought this charger would "just work", even if slow (low amps).

 

[DonTom]

It does has a lithium setting. It's lit up in the top photo.

OIC, that was difficult to read.

Are you sure you're not in the six-volt mode? I see that "6V" right after your setting.

-Don- Auburn, CA

 

[Mark_K5LXP]

Force Mode. [Press & Hold for 5 seconds]
Force mode allow the charger to manually begin charging when the connected battery’s voltage is too low to be detected. If battery voltage is too low for the charger to detect, press and hold the mode button for 5 seconds to activate Force Mode, then select the appropriate mode. All available modes will flash. Once a charge mode is selected, the Charge Mode LED and Charge LED will alternate between each other, indicating Force Mode is active. After five (5) minutes the charger will return to the normal charge operation and low voltage detection will be reactivated. CAUTION. USE THIS MODE WITH EXTREME CARE. FORCE MODE DISABLES SAFETY FEATURES


You would think a "smart" charger that is able to detect a particular chemistry would also detect state of charge in some way through iterative current levels or something, but it wouldn't hurt to see if force mode wakes it up.

Mark B.
Albuquerque, NM

 

[Yoshi]

Hi,

I read how to force it on. Press mode button for 7 seconds and all the lights should blink, then you select the type of battery. Mine is not doing that (all the lights flashing). I put it back on my mower battery and still would not go into force mode. Maybe something is wrong with the charger??

Another question.

Instead of changing out my lead acid WFCO, I'm thinking about getting a victron IP22 charger and connecting it full time to either my busbars or directly to the battery. Are there any concerns with leaving it on all the time when on shore power? Or would it better to have a switch of sorts?

 

[Mark_K5LXP]

Hard to say if it's broken or really smart. I might mess with it on a known discharged battery and see if it lights off on that. A call or email to their customer service might reveal something, like the version you have has different operating instructions or mode functions. Sucks that you have to put this much thought into something that should be "plug and play".

The only concerns I have with leaving chargers on shore power continuously is losing power, and having the batteries go flat as I obliviously think they're being maintained. My RV sits 30 feet from my back door and I still disconnect the battery for storage. Weeks can go by that I don't think to check, and by then they're wounded or dead. The other concern is damage from surges and transients. Equipment not connected to the mains is way less likely to get zorched. It's one thing if you "need" this stuff powered all the time and that's an assumed risk but if it's just for storage I disconnect and unplug.

Mark B.
Albuquerque, NM

 

[garyb1st]

Might just be really slow. I have a 4.5 amp Battery Tender charger and when I tried to charge both batteries together I wasn't sure if it was charging. When I first bought the lithium batteries I charged each one overnight. That supposedly brought them up to 100%. Other than a light indicating they were fully charged, there was nothing on the charger to indicate what the ending voltage was.