How to charge permanent mounted battery

Hello, I would like to have my lipo permenatly fixxed to my board, just like the boosted board has. I currently have a 12AWG wire running through the wood of my deck from the back tructs to the front. Now I would like to solder the charge leads of my lipo to those wires and somehow “split” the charge leads from the lipo so i can charge it without having to dismount them.

I was thinking of using a switch that would close the connection from my battery to the wires running to the esc and opening the connection from the charge port to my lipo’s charge leads ? Would this be a viable solution or is there something better I can/should do ? If not, what switches should I use ?

Lipo: VESC:

not to sure, but i think a loop key switch and connecting a bms may be an alternative to exposing your balance plugs.


first what battery configuration are you going to use? and what charger are you going to use?

this is how i have my batteries, i used 4-3S pack and configured this into 2-6S packs. this configuration can be use in 2 different mode (6S and 12S) via a DTDP switch. the yellow xt90 connector is for a anti-spark key loop, this prevent the charging current from getting to the esc.

i included the charging port, the balance and the volt meter with a 3.4V alarm port into the enclosure , for this i just solder a jst connector to the balance lead and installed a micro on/off switch on to the negative wire of the extension balance lead that goes to the volt meter.

Well, I would like to start with a single 3S pack to which I’ll probally add another 3S pack in the near future. I’m going to use the VESC cutoff settings to disable the board if my batteries aren’t providing enough voltage, So i wont need the voltmeter/alarm port. The ballance wires are only needed for charginf so I have no problem with those…

I do however like that DTDP switch, It gave me the idea to use a 2 way switch or something (if those exist) State A : lipo wires connect to charger wires State B: lipo wires connect to esc wires The only problem i have with this solution are sparks ?

ps. Sorry for my crappy paint skills

For the spark check this

I updated my sketch. I would prefer to use a switch over a loop key, because i’m afraid that I might plug in the charger without pulling out the loop key first. With this switch solution, It doesnt matter. Your charger will not find the batteries if you didnt switch it to charge mode.

How did you know howmuch amps the switch had to be able to handle ? if batteries provide 5000mah @ 20C, would that mean my switch needs to be able to handle 100amps ?

Check the switch rating and get the watts W=v*a And check how much watt you are going to be using

using by ? the esc, motor or charger ?

Your whole setup If you are using 6s that’s 22.2V x 35 amps that will be 777 watts

how did you get those 35 amps?

There are not many switch options that can work.

  1. Vedder antispark
  2. @lowGuido has a breaker that is an actual switch.
  3. @torqueboards has an anti spark switch.
  4. Buy a space cell :wink:

A simple loop key is a good cheap option but not very elegant.

I am not trying to switch my esc off, well not directly. I want to be able to select the circuit. Battery to ESC or battery to charger. (battery to charger = switching esc off indirectly)

Currently i’m looking into heavy duty SPDT switches, which shouldn’t spark since they are designed for such purposes.

On my previous built I installed a watt meter and keep a log. from this normal real world data use I determine the average watt use by the eBoard with a load of my weight.

I am using this rocker switch.

It’s not a SPDT but a DPDT. The reason I go for DPDT is that I could hook up both poles to be able to support double current draw.

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if you isolate the ESC with a switch you are essentially switching the battery to the Charge circuit, aren’t you?

Normally people use a switch to simply isolate the ESC from battery. It’s to turn your board off. You can actually charge your battery whether the ESC is isolated or not.

So what exactly are you trying to do?

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In my thread I specifically posted how to do Antispark with 100 Ohm resistor. It’s cheaper than getting your self an XT90 anti spark. Basically what Antispark does is limiting the current draw of your ESC capacitors when all circuits are connected. By providing a small resistance, it can’t draw that much amps in short period of time, hence there is no spark. But afterwards, you would need to connect the bigger power connector. Here is a simple diagram of an antispark

So you connect the auxiliary first (no sparking already), then connect the power connector. That simple. With the XT90 loop key tutorial, it’s all happening in 1 process as you plug the XT90 together (male and female).

But I got to say the way you think it’s abit strange. Why do you want to have such connections? Either to battery / to charger. The safest way is just to disengage the battery from the ESC completely and make separate cable port for charging (branch it / parallel it from the battery). I believe you would like to install the balancing charger and or powersupply within your electric longboard as well. If that is the case, then you should look for a BMS. BMS is just much smaller and does what balancer does without the bulk of box, displays and other charging features.

I recommend you to read my build, I hope I would shine some light for you. My build components have quiet high similarities as yours. If I am correct with what I mention above, then you should read it!

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This wouldn’t harm the esc ?

Yes, but what if you would start charging and forget to unplug the loop-key which disengages the battery to esc connection ?

You could use this, it has a switch integrated in the circuit, easy !