Reliable Voltage Meter ?

[Del 80]

Back in the day (about ten years ago) I got my first Ebike......a Powacycle Salisbury, which I thought was quite good, back then there was no handlebar mounted display, so I fitted this homemade voltage meter, which worked very well, and I always knew how much juice was left in the battery.......fast forward 10 years and the Pendleton is now on the road, it DOES have a handlebar display, but it's only a simple thing with 4 or 5 lights on it.......I'm looking at adding a volt meter, to tell me the exact voltage at all times.......anyone got any suggestions ?.........

 

[saneagle]

It's better to use a wattmeter. They show current, volts, watts, amp-hours and watt-hours. Either get one with a remote shunt (most are ugly) or remove the shunt and install it remotely, or make/buy your own shunt and install it remotely.

This one looks fairly waterproof:

0-60V Battery Tester High Precision Digital Wattmeter Accessories with Backlight | eBay

Find many great new & used options and get the best deals for 0-60V Battery Tester High Precision Digital Wattmeter Accessories with Backlight at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

 

[StuartsProjects]

Carefull with Wattmeters, some are close to invisible outdoors;



The display needs to be of the reflective\transflective type that can be read even in bright sunlight.

 

[StuartsProjects]

The other one linked to in this thread looks like it might be the right display type, but it would be good if someone who has one would report back if its visible in bright sun.

 

[saneagle]

Carefull with Wattmeters, some are close to invisible outdoors;

View attachment 52582

The display needs to be of the reflective\transflective type that can be read even in bright sunlight.

I have one of similar to that (GT), and it's fine in the sunlight. It looks like your back-light isn't working.

 

[StuartsProjects]

It looks like your back-light isn't working.

Backlight is working.

 

[saneagle]

Backlight is working.

Maybe yours has a different resistor limiting the current to the backlight. What about changing it to a lower value?

 

[StuartsProjects]

Its nothing to do with the backlight.

A transflective LCD display is highly visible in direct sunlight and does not need a backlight outdoors. Here is a transflective LCD on one of my balloon tracker receivers;

 

[WheezyRider]

It's better to use a wattmeter. They show current, volts, watts, amp-hours and watt-hours. Either get one with a remote shunt (most are ugly) or remove the shunt and install it remotely, or make/buy your own shunt and install it remotely.

This one looks fairly waterproof:

0-60V Battery Tester High Precision Digital Wattmeter Accessories with Backlight | eBay

Find many great new & used options and get the best deals for 0-60V Battery Tester High Precision Digital Wattmeter Accessories with Backlight at the best online prices at eBay! Free delivery for many products.

www.ebay.co.uk

No, it is not waterproof. Mine burned out when it got damp.

 

[saneagle]

Its nothing to do with the backlight.

A transflective LCD display is highly visible in direct sunlight and does not need a backlight outdoors. Here is a transflective LCD on one of my balloon tracker receivers;

View attachment 52584

MIne is the same and worked fine. I had it on my bike for ages. You can see it in this thread post#11:
(80) The Best Value Wattmeter | Pedelecs - Electric Bike Community

My figures are black against a lit background. Yours are white against an unlit dark background.

 

[saneagle]

No, it is not waterproof. Mine burned out when it got damp.

Add some silicone sealant then. It's only a couple of screws. You have to open it to remove the shunt. With the shunt removed, it doesn't get hot so you don't need the ventilation. Read that thread linked above if you need some ideas. You guys like to make things so difficult.

 

[Del 80]

Well, it seems that there is a bit more to it, than just wiring a volt meter up to the battery........I think further research is called for........

 

[Nealh]

If you just want a basic voltage readout only, then a £2 two wire one on ebay will work one just needs to house it in a W/P project box.

 

[StuartsProjects]

My figures are black against a lit background. Yours are white against an unlit dark background.

The backlight is working as in lit as I mentioned earlier.

Black characters = Transflective display and you can read it outdoors.

White characters = Non Transflective display, difficult to read outdoors.

So your power meter has a transflective display, mine does not, plain and simple.

 

[Del 80]

If you just want a basic voltage readout only, then a £2 two wire one on ebay will work one just needs to house it in a W/P project box.

Yes, that's it.....just one that gives a constant voltage read out.......

 

[saneagle]

Yes, that's it.....just one that gives a constant voltage read out.......

That's the problem. You won't get a constant readout. It'll go up and down all the time depending on how much power you use. Watt-hours or amp-hours are more useful because you can see how much battery you've used and whether your battery is deteriorating, and by how much. You learn a lot about how your bike works when you have a wattmeter showing all the data in real time. The installation work is nearly the same.

 

[StuartsProjects]

Yes, that's it.....just one that gives a constant voltage read out.......

Might be OK, but only might.

Over the many years I have been doing electronics, I have used a number of the LED type voltage displays and whilst they are perfectly OK indoors, put them outside when its sunny and you see very little.

But they only cost around £2.50 so no harm done in trying one.

The LCD4 I have on eBrompton will display battery voltage and you can see from that value what state the battery is in, how much load its under etc.

This type of display might be OK, the black characters suggests its a transflective LCD, so might be good outdoors.

 

[WheezyRider]

Add some silicone sealant then. It's only a couple of screws. You have to open it to remove the shunt. With the shunt removed, it doesn't get hot so you don't need the ventilation. Read that thread linked above if you need some ideas. You guys like to make things so difficult.

Sure you can, just don't want people to be misled in thinking it's waterproof out of the box. Very few of these things are.

 

[Nealh]

The ones I have used in the past fluctuate with voltage , one only has to oayse for a few secs to get a steadier pack voltage.

 

[WheezyRider]

I've been using these recently. You can get an external shunt version if required. And of course, if used on the bike you will need to waterproof. It will go up to 100V, whereas most others will only go up to 60V.