Adding a volt meter to the Rad Rover battery?

[syl3]

Does anyone know, is the charge port a good place to tap a volt meter on a Rad Rover battery. My other thought is at the headlight power cables may work, then you could just turn on the headlight to check voltage. Unless the voltage is stepped down at the headlight possible to usb 5v. I will check when I get a chance.

 

[pete]

I believe it's 52 volts @ light, on a full charge

 

[watts888]

I just ordered a couple of voltage displays to mount on my 'dashboard' and plan on plugging them into each battery's charging port. Simply unplug it and plug in the charger when it is time for a charge.

https://www.amazon.com/dp/B073GG3DWF/

 

[pete]

I ordered this one, it has a really cool display showing either voltage or percentage.

https://www.amazon.com/dp/B07KS1G585/

 

[syl3]

Thanks guys, it will be great to see the actual voltage on the fly

 

[watts888]

I can report that the charge port does not show the voltage of the battery, it is connected through the BMS (battery management system) and only shows a low voltage. My voltmeter will be here tomorrow I believe, next I will look at the front light, for measuring voltage. I don't really want to cut into the wiring at the battery or battery mount as this may void the warranty.

I tested with a plug that fits the terminal, and the voltage is about .1v. I used to make camera parts so I have good collection of different plugs. This does not surprise me as this is an intelligent battery with a built in balancer and thermal protection using a BMS logic board. It is not connected directly to the cells. If it was then you would need a balance port and a n intelligent charger/balancer.

 

[pete]

I build custom lithium battery packs of all chemistries. The bms controls the ground side of the pack using mosfets as the switch. It is either open or closed based on cell voltage, current and temperature. No or low voltage at the charge port would indicate an open circuit. How does current from the power supply flow in an open circuit? Right it doesn't.

You should be able to get a pack voltage reading from the headlight terminals.

 

[watts888]

Volt meter installed, on the head light circuit. Works great, just turn on the headlight and I get a voltmeter reading. I only want to take readings now and then to get an accurate reading of power left. This works perfectly.

Once again the charge port on the Rad Rover does not give a reading of Lipo voltage. This is actually neater, no need for a switch. It was easy to solder the wires on the connectors, piggyback to the original connectors after removing a little of the heat shrink tubing. And then reinstalling new heat shrink and zip tying to original harness.

 

[Hoggdoc]

Does anyone know, is the charge port a good place to tap a volt meter on a Rad Rover battery. My other thought is at the headlight power cables may work, then you could just turn on the headlight to check voltage. Unless the voltage is stepped down at the headlight possible to usb 5v. I will check when I get a chance.

Head and taillights run at bike's battery voltage.

 

[BMoreySurfs]

One of the reasons I outfitted my Himiway Cruiser with Nite Rider rechargeable led front and rear lights is to have the option of not draining down my battery. I have learned by experience that even the Samsung 48v 17.5aH battery has a range pretty much good for 60 miles if you manage the power right it can be cut dramatically while riding at night with the factory lights.

Let us know what you learn on the Rad Rover as it will likely translate to our eBikes too. Wherever I ride I have become accustomed to press the button on the battery at the start of a ride and middle of a ride to help gauge how much assist to use and not rely on the display gauge on the screen.

 

[CloneWerks]

Bike computer, Cadence meter, and now I sort-of want to install a voltmeter... my bike handlebar is going to look like Knight Rider's dash before I get done (LOL).

 

[rgsparber]

Does anyone know, is the charge port a good place to tap a volt meter on a Rad Rover battery. My other thought is at the headlight power cables may work, then you could just turn on the headlight to check voltage. Unless the voltage is stepped down at the headlight possible to usb 5v. I will check when I get a chance.

If you expect the voltage to tell you the state of charge, you may be disappointed. It is only a rough estimate.

 

[Voltaire]

i would say a voltmeter is the very best indicator of when your battery is going to stop, i always install voltmeter using throttle wires.
I hav 52v battery, fully charged 58.8v, my bike will always stop running at 42-43v... consistently over one years riding

 

[Voltaire]

If you expect the voltage to tell you the state of charge, you may be disappointed. It is only a rough estimate.

you mean bar style meter, not numerical, right

 

[Voltaire]

Does anyone know, is the charge port a good place to tap a volt meter on a Rad Rover battery. My other thought is at the headlight power cables may work, then you could just turn on the headlight to check voltage. Unless the voltage is stepped down at the headlight possible to usb 5v. I will check when I get a chance.

depending on your throttle configuration, on a Voilamart type 6 wire, i sue 2 wired from the throttle to measure voltage

 

[rgsparber]

If you expect the voltage to tell you the state of charge, you may be disappointed. It is only a rough estimate.

I run a State Of Health test on my battery yearly and use a Coulomb Counter to estimate my State Of Charge. It isn’t perfect but far better than voltage monitoring.