A simple inline meter to read 8S/32v power like gas gauge

[Nobuo]

My gauge arrived today and I couldn't wait to install it and try it out. Works ok, easy to read even during the day. Don't know how accurate it is. Need to use up the batteries to 3.7v and see what percentage I get. The only complaint is when the percentage displayed goes up and down with corresponding throttle use. Only when you are off the throttle that the display figure stays steady Giving you a "true" percentage of remaining battery level.

Will build a mini matching enclosure to protect device. For the price and being compact enough, I think it serves its purpose.

:lol: :lol: :lol:

I really laugh on this, but this is a genius work!

So I imagine you are not working with any F1, to F6 board functions (and the momentary button) and you use a separated swtich to ON and OFF

 

[sl33py]

What about one of these:
http://www.batteryspace.com/fuelgaugeforpcbof296vli-ionbatterypack.aspx

Those are nice. I'd use one, but you need to specify which voltage and looks to max out at 10s (for 37v one). One thing i like about the one on ebay is it's configurable for 3-14s or something like that. Tons of flexibility if you run different packs like i do.

 

[sl33py]

The only complaint is when the percentage displayed goes up and down with corresponding throttle use. Only when you are off the throttle that the display figure stays steady Giving you a "true" percentage of remaining battery level.

Sorry i missed you mentioned you are building an enclosure for it already. (need more coffee)

Idea - you smart folks let me know if this would work: Capacitor inline with this meter to even out the dips under throttle? I have some spare 63v 2200uF caps for VESC or could get something smaller (that 2200uF cap is almost as big as this display/gauge) but that in theory should even out the voltage "dip" when accelerating and give you a more constant voltage - correct? Even a small one might be sufficient to even this out and give you a better constant display?

Am i way off base here?

 

[MrDude_1]

The only complaint is when the percentage displayed goes up and down with corresponding throttle use. Only when you are off the throttle that the display figure stays steady Giving you a "true" percentage of remaining battery level.

Sorry i missed you mentioned you are building an enclosure for it already. (need more coffee)

Idea - you smart folks let me know if this would work: Capacitor inline with this meter to even out the dips under throttle? I have some spare 63v 2200uF caps for VESC or could get something smaller (that 2200uF cap is almost as big as this display/gauge) but that in theory should even out the voltage "dip" when accelerating and give you a more constant voltage - correct? Even a small one might be sufficient to even this out and give you a better constant display?

Am i way off base here?

you're a little off.
a cap will not help. The voltage really does drop under use. Thats called voltage sag.
when you put a load on the battery, larger than it can handle, the voltage will drop... its normal.

just let off the throttle to see the true amount.... or watch it under load to see how bad your battery is dragging down.

 

[sl33py]

Thanks MrDude! I technically knew that... Thanks for explaining to me again. A millisecond draw would smooth out w/ cap, but several seconds draw on battery it wouldn't help.

 

[cdn]

[attachment=0]GEDC0069 %28640x428%29.jpg[/attachment
[/quote]

:lol: :lol: :lol:

I really laugh on this, but this is a genius work!

So I imagine you are not working with any F1, to F6 board functions (and the momentary button) and you use a separated swtich to ON and OFF[/quote]


I've got the display wired after my electronic HV switch. Looks like 21% on my display is when I start walking.

 

[mjp8081]

OK, so I've been using mine for a couple rides, and as far as I can tell, it is an excellent power gauge. The bars and percentage are basically accurate and I'm super pleased with it.

There is another model by the same maker, more expensive but more display info, including Ahs:
http://ebay.to/1if1p38

Here is a cut and paste of the "f" functions. The wording is a little confusing, and the 20w (soldering) iron info is probably missing a diagram. To enter setup mode, connect battery power while holding down the Bottom "down key" button on the back of the meter. The basic version is this:

F1:Backlight delay off
F2:Backlight voltage trigger
F3:Sleep function
F4ower on self-test
F5:Voltage display
F6:Logo display
---------------------------------
C. Function settings:

[strike]1. Use the pointed iron (20W) to connect the corresponding F1-F6 connection points in the function setting, you should operate in power-off condition, and make the adjusting effective after re-powering.[/strike]

2. The back is not connected in the factory default, functions: the backlight keeping on, the percentage display, no sleep state, no self-inspection, no Logo.

3. The following is the connected F1-F6 points function:[strike](See Pic3)[/strike]

F1: the backlight delay turn-off function; enter the low-power state (100uA) after displaying 10 seconds , the LCD displays but the backlight turns off. Press the OK key and the backlight turns off again after 10 seconds’ lighting. This mode needs the OK key.

F2: the backlight voltage trigger function; enter the low-power state (100uA) after displaying 10 seconds , the LCD displays but the backlight turns off. When the voltage changes,the backlight automatically lights on for 10 seconds, or press the OK key and the backlight turns off again after 10 seconds’ lighting. This mode needs the OK key.

F3: sleep function; enter the ultra low-power state (<20uA) after displaying 10 seconds , the LCD and the backlight turns off. Press the OK key and the backlight turns off again after 10 seconds’ lighting. This mode needs the OK key.

F4: power-on self-inspection; every time the electricity module is powered on, the LCD displays strokes for 2 seconds, and then displays the selected battery type for 1 second, finally displays the electricity capacity.

F5: voltage display; the current battery voltage is displayed only on the right, the battery symbol on the left is still in accordance with the selected type.

F6: the LCD shows the Logo on the lower left.


I also made a rough PDF of the instructions/manual from HTML:
View attachment Baiwat LY5 Battery Meter.pdf

 

[mjp8081]

I was surfing around, and found a Chinese site selling these Baiway meters, this one (same size) toggles display between Ah, A, %, V using front button:

http://world.taobao.com/item/7457682222.htm?fromSite=main&spm=a312a.7728556.w4023-1809775439.10.VbtURd
As far as I can tell, it does not have the other features and settings. Use the "translate page" function to read, and navigate around to see other models and wholesale prices (cheap)

Here it is (marked 90% up) on eBay:
http://www.ebay.com/itm/LCD-Battery-Capacity-Tester-Indicator-for-lead-acid-lithium-battery-iron-battery-/261932141845?hash=item3cfc5f4d15

 

[astilwell611]

I think you guys are seriously overthinking this. I use one of these on my board.

http://www.ebay.com/itm/DROK-0-56-Waterproof-DC-15-120V-Digital-Voltmeter-Voltage-Measurement-Gauge-Re-/111724555824?hash=item1a034d6e30

Waterproof, shockproof, dustproof and it reads out the exact voltage of the packs. I have it inline after my ignition key so when the board is on it is on, board is off it is off. It works great I love it.

 

[xdaass]

although the plate doesn't show accurate voltage it give a fear indication of how much i used and how much is left,

this is my setup. working good and stable
https://goo.gl/photos/REtUWPr8xYwT2m5G6

 

[vince086]

I know the title is for 8S setups so this one won't work but will still share some info.
Bought this LCD Battery Capacity Tester Indicator for 12/24V Lead-acid Lithium LiPo Battery. Just tested it out using a variable voltage power supply and the reading seems close enough (set to work with a 6s Lipo). The reading isn't instant, it takes a few seconds for the display to refresh and display the real value.
Here are some pics with the real voltage and indicated battery percentage: Imgur album.