Building my first iPWM mod, need help

So im in the middle of building my first iPWM mod and im having some issues.

Heres my parts list to start
Big Al’s 2s-6s Lipo Intelligent PWM Board (iPWM) w/pot

Alpinetech Blue 1590N box LED cut out


12mm Switch

Source 40mm 510

I have 2250 mah 2s and a 1500 mah 4s battery to test with it.
When I hook up the 2s, everything is fine.
When I hook up the 4s, starts up find but its always has the display on saying 2.35, I dont understand. It still hits great and all but the display never turns off.

I cant seem to find alot of info on this board other then its a great board to use. Any idea’s?

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Maybe @Whiterose0818 can help you out.


Ask @Whiterose0818 what alternate boards he would recommend.
There was a thread a few years ago and he mentioned there were 3 or 4 other alternatives to the Big Al’s boards that he preferred.


Take a read of the Whiterose thread. There are some links to some Facebook groups if I recall


Are you pressing the button once and then hold it down to get this 2.35 reading?
Does it stay the same when you disconnect and reconnect the battery?
If you’re sure the 4s battery is working fine the display should be flashing 4 times when you connect the battery. I only use these boards with 2s and have not seen a value on the voltmeter which is on all the time.
I’ve found the best info on these boards on the facebook group and one of the mod shop websites. I’ll have a look later if i can.


I got faith that reading or even joing FB will help u alot bud. U really gotta read up on the board too as they arent friendly board to board. Gl to u as always!


another plug for ric grove @Bryn when do i get paid? lol


some vm have a hard time reading pwm.
what load do you have on it?

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this might be helpful

As soon as I plug in the 4s, it’s stays on 2.35 and never turns off. Just worried it will drain the battery. It’s not completely together yet. Led just went out and waiting for red bezel for pots and red switch. Led is yellow. Trying to get a Superman theme.

When I do the commands it does what it’s supposed to do. Like it works fine. But when I’m not taking hit off it the led reads 2.35. Very strange. It says 2.35 then flashes 4 times when I hook up the Lipo and does it’s test but then the 2.35 appears again. With the 2s it stays blank till I take a drag. It shows the voltage out when I’m firing it on both batteries. I wanted to go with the nlpwm but they have been sold out so from I’ve been reading this was supposed to be second best.

Apart from the videos I haven’t found much about diagnosing the iPWM boards. If you are on facebook I would try their group.
I should try one of my iPWMs with 3 or 4 s just to see if they may have the same issue. I have one of the side mount boards with the pot on board but the others are sled mounted ones and a bit older.

I joined the group, posted my question then it seems I got booted out of the group. Not sure what’s going on. Been emailing back and forth with big al’s But he says his board is fine. Wants more pictures. I sent videos and pictures and what not. Hopefully he can help me out

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I’ve tried one of my iPWM sled mounted boards on my psu to simulate 4s. Unfortunately my psu only provides 5A so the test cycle failed. It behaved completely funny due to the lack of juice so I can’t confirm if my mod would behave the same on 4s.