DC DC Charger - what profile should I use?

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Am expecting a 4S 100Ahr "A Grade" LiFEPO4 JK-BMS from Amy (Luyuan). In anticipation of using this as a camping battery in a recreation vehicle, about 6 months ago I purchased a Atem Power 40 A DC DC charger model VABG008A. Atem Power come from a company in China - Zhejiang Vicoffroad Vehicle Accessories Co., Ltd

Zhejiang Vicoffroad Vehicle Accessories Co., Ltd. - Camping Light, Battery Box

Zhejiang Vicoffroad Vehicle Accessories Co., Ltd., Experts in Manufacturing and Exporting Camping Light, Battery Box and 0 more Products.

vicoffroad.en.alibaba.com

and have a presence here in Australia - website- vicoffroad.com.au
Even though the profile is labelled "Lion" on the charger settings I was reassured that the profile was suitable for LiFePO4.

There were a few comments on Amazon that this "Lion" profile was not suitable for LiFePO4 as it had an unaccepably low return to boost voltage of 12.4V.

I decided to bench test the DC-DC charger and check the "Lion" and "Lead" profiles. The user manual mentions some voltages for profiles but is incomplete. It does describe a floating voltage of 13.5V for AGM/Gel, Calcium, Lead and says there is no float voltage for LiFePO4.
My testing:
Lion - softstart then full charge to 14.4V and then CV until current tapers to 4A and full charge light comes on and then there is no maintenance charge or float voltage and battery voltage slowly falls (depending on load) until it hits 12.35 V and then full charge to 14.4V starts again. So yes there is a return to boost a 12.4V which is close to an empty 4S LiFePO4 pack.

Lead - softstart then full charge to 14.4V and then CV until current tapers to 4A and full charge light comes on. The charge current is zero if there is no load and the pack drifts to its resting voltage, if there is a load then there is charge current to match outgoing and battery floats at 13.5V. I presume that there may be the same return to boost voltage of 12.4V but the volatge doesnt get here because of the float charge able to maintain a CV 13.5 ( not aware if there is a time limit)

I have taken this up with vicoffroad.com.au and gently asked them - please explain the "Lion" profile and was brushed of with a reply showing a LiFePO4 volts vs SOC table. No reply via the alibaba messaging service so far.

So without going down the track of trying to return the DC DC charger - the "Lead" profile as I have described looks possibly suitable for my 4S pack?

I notice Redarc and Renogy have gone away from listing battery chemistry profiles but describe the profile voltages.

I would welcome comments about using this "Lead" charging profile for my LiFePO4 100Ahr 4S pack.

 

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First are you sure the battery at just 100ah wants to be charged at 40 amps? Are you sure the alternator has 50-60 amps headroom on capacity? Any plans to charge by idling for an extended period while camping?

I would not be bothered by the 12.4 return since I would think the primary use would be to gain full charge while driving. Not really going to cycle the battery 12.4 - 14.4 continuously like a utility powered charger. Otherwise the lead is the same profile with 13.5 float and would be fine while in transit.

Just my random thoughts.

 

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Luyuan (and @Steve_S say charging up to 0.5C is ok (50A) so max rate is ok. Alternator is either 75A or 90A

The concern I have about the "Lion" profile if I start with fully charged pack and drive for 3hrs and stop the SOC will be less the load used for 3hrs from fridge as no charging occurs once hit 14.4V and so arrive without the LiFePo4 being fully charged.

 

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Is the fridge really running on 12v for the heater or compressor? Or is this a propane fridge with 12v controls? The 12v controls will not significantly discharge the battery.

Otherwise set it to flooded and not worry.

50 amps could be a significant burden on the alternator depending on what accessories are running.

 

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Load is a compressor fridge and draws about 7A when cycling on. The "Lead" Profile of this DC-DC charger is very similar to the LiFePO4 profile of the newer Redarc BCDC series (14.5V/13.6V) but with a more realistic return to Boost of 13.2V for LiFEPO4 - see attached.