Sterling ProDigital Advanced Alternator Regulator: turning on and off for LiFePO4 bank charging

[vas]

good morning,

have finally concluded home testing on a 304Ah 24V LiFePO4 battery bank with diyBMS controller and shunt, bought a BlueSea contactor and a Class-T fuse, so ready to move the lot onboard.
Now, charging sources are 3, two of them are sorted as they are a Victron MPPT solar charger and a Victron Multiplus both connected to a raspberry pi running VenusOS and charging states, levels and current is controlled by the rpi through the instructions it gets from the BMS. diyBMS talks Victronspeak and the main reason I opted for this BMS (as well as it doesn't resort to mosfets to disconnect power.
OK, sounds complicated but works fine.
Third source though is port engine alternator (60A) which is currently routed through a Sterling ProDigital Advanced Alternator Regulator, which needs to be also controlled as I tend to move from one place to another midday early afternoon and the battery will be full from the solar panels.

So after this intro, the simple Q is:

am I right in that passing through a 1A relay (onboard the BMS controller-will check with an ampclamp typical loads on this wire) the yellow cable (which is going to ignition or D+ or wherever it gets +24V in my case) I can safely turn Sterling output to the bank on and off at will without burning anything?

Or I need to consider something more advanced?
Am I right in that diodes cannot be destroyed in the alternator even at 2000rpm if the yellow cable is grounded and effectively the sterling output is killed and later on re-enabled?


cheers

V.

 

[vas]

pasting the reply I got from Sterling (asked them lunchtime yesterday) my Qs in orange:

We’d recommend you consider installing a BB242435.

RE: Questions –

can I cut the 24V supply to the the yellow cable (which is going to ignition or D+) to safely turn Sterling output to the bank off and then on again based on BMS's instructions without burning anything?
No, as cutting the feed mid-charge will typically lead to a voltage spike.

Or I need to consider something more advanced?
The BB242435 is a current limiting and isolating battery to battery charger. It will ensure that you do not overwork/burn-out your alternator from the heavy demands that lithium will put onto it, and it will also, so long as it is installed correctly between your starter system and your lithium system, also protect you from spikes on either side. This is the option we would recommend.

hope it may help someone thinking of achieving something similar for LiFePO4 charging.

cheers

V.

 

[roaringgirl]

I have a Balmar regulator, the BMS can shut down the power to the regulator (this is the config Balmar recommends). However, in practice the regulator shuts down power generation when float voltage is reached and the BMS doesn't have to do anything.

 

[vas]

well, was hoping I can do something similar with my Sterling. Doesn't look like it can, not particularly keen on letting the Sterling alone charging the LifePO4, so will probably keep the alternator/Sterling combo hooked on the T105, and disconnect the LiFePO4 when BMS is not happy, leave the whole system running on the Trojans... Else need to buy a B2B charger that I can turn on/off from the BMS. Not too keen paying yet another piece of kit for that.