Current best way to monitor battery time left?

[shambolic]

It's logically got to be 4 LEDs , then you would know when to head home...but logic doesn't always prevail. This is kind of catering for those 'most people' ( me included) http://batt-man.com/batt-man-DashBoard.

What's the situation with say an hour charge, do Lipos do an 80% charge in a short time like some other Lithium batteries?

 

[Tubamanandy]

How easy is it to wire up a GT Power wattmeter ?

 

[Deleted member 4366]

Very easy if you can solder - not that soldering is difficult!

 

[Deleted member 4366]

Diagram

 

[Aushiker]

Very easy if you can solder - not that soldering is difficult!

My first attempt at soldering yesterday may suggest otherwise

Andrew

 

[Deleted member 4366]

What were you trying to solder? I can give you instructions to make it easy. I taught electronics at school. Every 11 year old kid was able to do it. You've got no excuses.

 

[eHomer]

My first attempt at soldering yesterday may suggest otherwise
Andrew

Dave is quite right, it is easy, but the technique can be very unforgiving if you get anything slightly wrong, and you then end up with a total mess.

Soldering thick cable needs a high enough temperature iron for an absolute minimum length of time, or the insulation runs and the flux boils away.

I always use a "solder station", which is a fairly high wattage iron with a variable temperature, thermostatically controlled.

The type of solder needs to be compatible with what's already on there as well, or better still, use a solder sucker pump to clean off first.

 

[Aushiker]

What were you trying to solder? I can give you instructions to make it easy. I taught electronics at school. Every 11 year old kid was able to do it. You've got no excuses.

I was having a go at soldering some 12AWG silicone wire to a XT60 connector. Realised today I was going about it all wrong after watching a video and had another go this afternoon and it worked well.

I might yet pass electronics

Andrew

 

[shambolic]

I've bought this one http://batt-man.com/batt-man-DashBoard I will quit likely be back with lots of questions when it arrives.

 

[Deleted member 4366]

I was having a go at soldering some 12AWG silicone wire to a XT60 connector. Realised today I was going about it all wrong after watching a video and had another go this afternoon and it worked well.

I might yet pass electronics

Andrew

1 Always clamp the connector so that you're not chasing it around the table
2 For bigger stuff like that, a tin of flux helps. Dip the end of the wire in the flux, or you can dip the solder in the flux, so that it gets a good coating. Don't rely on the flux in the solder core. Cored flux is Ok for smaller stuff.
3 The biggest mistake people make is not leaving the soldering iron on long enough to heat up the mass of the wire and connector.
4. Trim the wire, then heat it up with the iron. Put a bit of solder on the iron's tip first to aid heat transfer. Heat up the wire, then add solder until it's saturated. Try and keep the iron on all the time. Don't try and paint the solder on with the iron. Leave the iron on for a few seconds after adding the last solder.
5 Heat up the terminal with the iron, and add a bit of solder. Keep the iron on until the solder has wetted onto the terminal. Leave a shallow blob.
6 Bring the tinned 12g wire to the terminal and squish it onto it with the iron. Allow plenty of time for everything to heat up and fuse. Always wait a few more seconds after you think it's ready before removing the iron
7 Allow plenty of time for the joint to cool down before you let anything move
8 Check visually that the solder is properly fused to the terminal

That's it. Obviously, if you have a heavy duty iron, everything happens more quickly, and it's easier.

The iron is only used as a heater. It goes on before you add solder, and stays on after you last added solder. You should try and keep it still. Only the solder should move during the soldering. No point in waving it around like a magic wand. No matter what you chant, it's magic won't be strong enough to make your joint good.

One last point: Don't try and solder in mid-air. You won't be able to hold your hand steady enough. Always rest your the side of your hands or elbows on the bench/table.

 

[awol]

2 For bigger stuff like that, a tin of flux helps. Dip the end of the wire in the flux, or you can dip the solder in the flux, so that it gets a good coating. Don't rely on the flux in the solder core. Cored flux is Ok for smaller stuff.
3 The biggest mistake people make is not leaving the soldering iron on long enough to heat up the mass of the wire and connector.

Any chance of a link to some reasonable flux and solder, the stuff I got to practice with doesn't flow very well and just seems to crackle and pop and dries dull and any flux just seems to be for plumbing.

 

[Deleted member 4366]

Good point. I forgot to say that you should steer clear of lead-free solder. 60/40 tin/lead is traditional solder. You can get it from Ebay.

http://www.ebay.co.uk/itm/Templers-Telux-Soldering-Flux-50g-For-Copper-Pipework-Brass-and-Mild-Steel-/151019213488?pt=UK_DIY_Materials_Plumbing_MJ&hash=item23297252b0

http://www.ebay.co.uk/itm/Solder-Wire-60-40-0-5-2mm-2-Flux-Reel-Tube-Tin-Lead-15-500g-/200967203181?pt=UK_Home_Garden_PowerTools_SM&var=&hash=item2eca94296d

 

[Geofft]

My 'fuel gauge' is rather more simplistic, I know to within a mile or so how far I can go on a full charge so I reset the tripmeter on my cheapo bike computer at every charge and leave the display on trip mileage so you can see at a glance how much you've used.

Ok, it doesn't take into account the myriad of variables involved but it gives surprisingly reliable and consistent results for just a fiver.....no soldering involved....

 

[Aushiker]

1 Always clamp the connector so that you're not chasing it around the table ...

Thanks for the detailed explanation. Now added to my file of instructions and manuals.

Regards
Andew

 

[shemozzle999]

I told you before: That wattmeter isn't suitable for an ebike as it stands. Look at the size of the pins on the connector and the tracks on the PCB. You'd need an external shunt of some sort, which they call "external sampling unit".

All the connections to the display could be made in the controller by using the controller shunt as the "external sampling unit".

 

[flecc]

My 'fuel gauge' is rather more simplistic, I know to within a mile or so how far I can go on a full charge so I reset the tripmeter on my cheapo bike computer at every charge and leave the display on trip mileage so you can see at a glance how much you've used.

Ok, it doesn't take into account the myriad of variables involved but it gives surprisingly reliable and consistent results for just a fiver.....no soldering involved....

My method too Geoff, very simple and has never let me down. Certainly far more accurate than 3 LED battery meters and better than many five LED ones.

 

[shemozzle999]

shame, that's the sort of clear display I need. Guess it wouldn't work any way because my battery is 48V. Reckon I might go with the Speedict. It looks fairly simple to setup?

Available in versions up to 80v,100A.

http://www.aliexpress.com/store/other-products/123351.html?categoryId=15370310

 

[shemozzle999]

It looks like it was originally designed to fit a case:

 

[Deleted member 4366]

It's a shame they don't sell it in the case. It would save a lot of messing about.
You could only use the controller's shunt if there's a calibration procedure. By the time you've opened up the controller and soldered all the wires, it would be much easier to make your own shunt out of a piece of battery wire.

 

[RobF]

Another vote for know your bike and battery.

I rarely need to bother with the trip meter as I can estimate the mileage of most journeys closely enough.