How to tell level of charge left in battery on the road

[Mercadr]

I have a battery pack in a triangle bag. This is my first battery. It doesn’t have a charge level indicator. Is the only way to tell the level while on the road on the bikes display?

 

[harryS]

I use these. A little hard to read in bright sunlight. A home made bezel/sun_shield helps. I wire them to the start button on my display, so they only power up when the bike is on. Also good for looking at battery sag when trying a new battery. Price is right.

Amazon.com

 

[Dewey]

I have a battery pack in a triangle bag. This is my first battery. It doesn’t have a charge level indicator. Is the only way to tell the level while on the road on the bikes display?

If your pack has xt60 connectors you could add in-line a Watt meter, or test the voltage output using a multimeter, they give you a snapshot. For example a fully charged 36v pack should measure 42v, and that will drop over time, once it drops 10v below what your manual states the pack is effectively exhausted.

 

[6zfshdb]

If you can find a plug that will fit your battery, there are many cheap digital voltage displays you could connect. It might be just as easy to plug the battery into the bike and read the display though.

 

[JES2020]

I have a battery pack in a triangle bag. This is my first battery. It doesn’t have a charge level indicator. Is the only way to tell the level while on the road on the bikes display?

Here is a watt meter for $14(free shipping) you can wire between the battery and the motor.

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[harryS]

The problem you'll have with the wattmeter is it's intended to go between the battery and controller, so you can't mount it on the handlebars for easy view,. Yt needs to use a short, heavy gauge wire to transmit power to the battery. Some people take out the shunt, mount that by the battery, and then they can run four light wires anywhere, but that's a pin in the neck to wire. I've done it temporarily, but I used an XT extender cable. ANother problem with it is it will drain the battery if you leave it on the bile for 10 days. Slow but steady current drain.

Another pic of the handle bar voltmeter. I just ordered another one.

;

 

[JES2020]

The problem you'll have with the wattmeter is it's intended to go between the battery and controller, so you can't mount it on the handlebars for easy view,. Yt needs to use a short, heavy gauge wire to transmit power to the battery. Some people take out the shunt, mount that by the battery, and then they can run four light wires anywhere, but that's a pin in the neck to wire. I've done it temporarily, but I used an XT extender cable. ANother problem with it is it will drain the battery if you leave it on the bile for 10 days. Slow but steady current drain.

Another pic of the handle bar voltmeter. I just ordered another one.

;

View attachment 105525

The problem you'll have with the wattmeter is it's intended to go between the battery and controller, so you can't mount it on the handlebars for easy view,. Yt needs to use a short, heavy gauge wire to transmit power to the battery. Some people take out the shunt, mount that by the battery, and then they can run four light wires anywhere, but that's a pin in the neck to wire. I've done it temporarily, but I used an XT extender cable. ANother problem with it is it will drain the battery if you leave it on the bile for 10 days. Slow but steady current drain.

Another pic of the handle bar voltmeter. I just ordered another one.

;View attachment 105525

My watt meter $14, turns off when the battery is powered down , so no battery drainage , I have had it sit thru the winter with no drainage on the battery. Also I mounted mine on the lower bar of the frame and can read it easily when riding, didn't even need to attach Anderson plugs as the wires on the meter fit tightly into the battery's Anderson's, I just used some bailing wire to support everything including the meter wires to the Andersons. Extremely easy, simple to do and bullet proof.

I forgot, these units also give many other data fields like max volts , max amps, max amp hours used during the ride. It actually scrolls thru 2 or 3 screens of data !

 

[Mercadr]

Thanks so much for the ideas! I’m going to start with using just the battery level on the display… then hook something up later that is more precise

 

[indianajo]

commercial throttles come with a red/yellow/green led on them. Red going up a hill is bad news.
Other ones have a voltmeter built in. I point mine down so I can see it in the sunlight if I think I'm developing an empty battery. Or decide to charge before going home or not at my summer camp. The voltmeter stays on all the time, and doesn't seem to run the battery down unduly.