12s battery / BMS which can be charged on 12v

Hey all, New here and wondering if you can help.

I’m designing a product that basically requires an efoil drive system. Problem is my power source is 12v which is extremely limiting.

Are there any BMS systems which i can charge a 12S battery pack at 12V.
My idea being that i have 48v going to the motor, but then charge that pack from the 12v source. Like 4 separate 3s packs.

Does this exist? Or would that involve 3 separate BMS boards.

Thanks in advance. Ali

Can you install an inverter? Then you can use the 120v wall chargers. With loss of course.

You can charge using hobby chargers that’ll do the separate packs method.

Also think about your 12v power supply. I’m guessing you are charging from a van. Is your solar up to snuff? Is your house battery bank large enough?

Actually from a boat. So have plenty of capacity to charge of leasure battery.

Would like to be able to have it constantly trickle charging the batteries then be able to use the power when required. I don’t require much run time.

Bms for 12s need 50,4v , all it does this let go the 50,4v through the battery until the cells hit 4.1- ( Check voltage and temp ) then takes control off each row to 4,2v/cell

You need to convert your 12v to 50,4v

Or split your battery in to 2 x 6s and use a classic lipo charger (dc 12v) pocket size performe well and cheap

Or buy a 10-15A classic power supply for 12s 50,4v and a convertor dc/ac to go from 12v to 110v or 240v to run the charger 12s to the battery bms

Yeah just build out 2 6s batteries and use a hobby charger to balance and charge. I don’t know how big your system is and how quickly you can regenerate energy but save enough energy for your day to day tasks. I have a 5000w battery bank and have no issues charging at lower amps. Once I get into higher amps there is a significant voltage drop from the house batts.

Thanks.:+1: Was expecting that to be the case but was hoping it wouldn’t be :grinning:

One of rdtech buck boost would work from 12v going to a 12s bms. Supposed to do 5amps, but might end up being less. Only 50v though


Not sure , seeing on its pdf manual :

Make sure that the input voltage is always at least 1.1times the output voltage. In addition, always ensure sufficient ventilation of the device for heat dissipation.

Yeah that is the case in their regular buck (step-down) only ones (DPS series), but the buckboost isn’t the case DPH series. Looks like a copy paste error from their other ones.

Here was one manual:

Due to the Buck & Boost function-ality, voltages can be converted both up and down.

I got one right at my desk that I have used for a battery charging my 10s scooter when its charger died (from a 19V laptop AC/DC brick). I was only charging at 2A because that was what the older dead charger used.

Looks like 10A max input current (120W) so you’d be limited to ~2.4A charging at 50V.

Tell us more about the boat’s power system and your electric propulsion needs. Voltage is only half the equation.

A 12si alternator on a small block GM is very different from a 300amp unit on a detroit series 60.

You must describe better for a better answer.