Schematic check and PS / Charger question

[Mike N]

Hi all, I'd like to run my schematic by you guys before pulling the trigger on my SBMS0 purchases. It's starting out as a simple van battery without solar yet, AC charging while mobile or stationary and a Victron Battery Protect for battery control.

For the power supply I'm leaning toward the Meanwell NPP-750-12 (Charger/Power Supply), it seems like it's a better fit than the NPB-750 (Intelligent Battery Charger). With the SBMS0 doing all the thinking and just turning the NPP power supply on and off, the NPB two stage charging seems like overkill. The NPP also has adjustable current.

Searching on the forum, Kenk mentions the NPB having more charging presets, but I'm thinking that's not as useful for the SBMS0. Egbert mentions "utilizes the Canbus protocol for customization, I wont be doing that. I'm guessing the downside of the NPP is that in case of emergency (without the SBMS0) I couldn't use it to charge my battery without physically switching it off when the battery voltage maxes out, it has a adjustable voltage but no auto cutoff as I understand. I don't see a way around the NPP's three stage charging curve when in Charger mode.

Your thoughts would be appreciated.

Thanks, Mike

[Dacian Todea (electrodacus)]

Mike,

EXT IO4+ will need to be connected to pin 8 (NPP-750) and EXT IO4- to pin 7 (NPP-750)

The rest of the schematic seems fine.

[Ken King]

Mike,

I believe it's worth the $20 difference to be able to set charging voltages and choose between 2 or 3 stage charging profiles to fit your application. The support folks a Meanwell are very good at explaining their equipment.  Also Mouser electronics has good pricing.

Good luck with your project.

[Mike N]

Dacian, thank you for finding that, it was left over from when it was a SSR.

Thanks Kenk, I’m happy to spend the extra if it gets me more functionality. Is the idea then that the SBMS0 shuts off the NPB before it shuts itself off at the end of stage 2 charging. I’ll reach out to Meanwell on Tue.

[Dacian Todea (electrodacus)]

For this particular application the extra functionality plays no role. Maybe the resale value could be better if you no longer need this in a year or two but there is no advantage in this particular application.

There is no multistage charging here just bulk charge and SBMS0 will stop charging when any cell gets to 3.55V

[Mike N]

Thank you Dacian, that’s what I was thinking. NPP it is, I like the idea of having the adjustable current.