Watt or Ah Meter Options?

[avoleoo]

Been using CA 2.4 for last 5 years and really like used Ah meter where I know precisely how much juice I have left. Now building my second bike and planning on using S12S with LCD3, however I believe the only measure is the battery bar which is not good enough for estimating range. What are other options besides battery bar?

 

[avoleoo]

Looked into these guys, but I would really like to find a smaller or rather more integrated solution.

https://www.ebay.com/itm/150-AMP-WATT-METER-WITH-SPECIAL-HEAVY-GA-WIRE-WIND-GENERATOR-SOLAR-DC-INLINE/272061542420?hash=item3f5821b014:g:w50AAOSwfVpYpd8V:sc:USPSFirstClass!33467!US!-1

Love CA, but it's outdated design and price point with the controller is no fun ......

 

[rote]

I hear you. First thing though, I think the S12S is a KT controller, right? If so, I think you need to run one of their displays for the controller to work.

In any case, I tried one those generic ebay 150A power meters (nice size, form factor). They're not that accurate and I think many of them can't display anything on the LCD if your battery pack is 48V and higher. That was my experience. So then I just used it as a meter when charging the battery but it died within a year. I now use one of these https://www.ebay.com/itm/DC6-5-100V-20A-Car-Digital-LCD-Combo-Panel-Gauge-Voltage-Current-Meter-KWh-Watt-/262681099373?vxp=mtr&hash=item3d29037c6d as my battery charging meter. Pretty accurate and quality is better - but it's kinda bulky, so not sure if you want to mount it on your bike as a watt/amp meter although I've seen some use it as such. Also, this keeps track of cumulated Wh, not Ah (just as fine for me). If you're going to draw more than 20A, they have other versions with an external shunt. Last, there is the Luna Cycle Batt Man which I've read decent reviews.

 

[dogman dan]

That meter will work to just measure watts, ah, wh, etc. But unlike the CA, it does have some limitations. If anything interrupts the connection, it has no memory of the current display.

Shouldn't be a problem, till it is. But that meter, or the cheap blue ones in metal box work fine, for cheap.

I do agree, the bars on displays are just too primitive. At the very least, you need a read out of actual volts to do your guessing. Just a voltmeter display is really cheap, like 3 bucks.


But in the end, nothing beats a DP ca and controller, even as nice as displays have gotten, IMO, they still suck till they have a wattmeter included.

 

[d8veh]

The LCD3 also shows actual battery voltage if you press the power button twice. You soon figure out the relationship between range and voltage.

The cheap wattmeters are OK if you modify them. You can add add an auxillary battery so that they don't lose their memory, and you can rewire then with a remote shunt so that you can mount them on your handlebars without having thick battery wires running all over your bike. All you need for a remote shunt is a piece of 14g or 12g wire about 5 or 10 cm long depending on the value of the shunt in the meter. In fact, you can even use your battery wire by soldering two sense wires to it about 5 cm apart.

 

[rote]

Hey guys, good to hear from the dogman and d8veh. Sorry, don't get on here much anymore. Apparently OP does not want to use a KT display (I think the KT-LCD3 is great, after the CA). Actually, the meter I posted does maintain cumulated Wh until you manually reset it by a button. So that's good.

I remember as a newbie reading about the shunt mod you could do to the 'Turnigy' watt meter. I didn't do the external shunt mod (per d8veh and Jeremy) and just ran the wires to and fro. Unsightly, but the main thing is that these more recent 150A power meters have a poor LCD display when running a pack 48V or higher because they no longer have a pot. This lessens the ability to read the LCD display at higher voltages. If you do the external shunt, I suspect you won't have a display problem but won't be able to calibrate due to the lack of pot so accuracy may be lacking. My 2 cents.

 

[avoleoo]

Thanks guys for your replies, I have placed an order for this one:

https://www.aliexpress.com/item/50A-New-TK15-Professional-Precision-Battery-Tester-for-LiFePO-Coulomb-Counter-Free-Shipping-with-Tracking-Number/32702066121.html

And I have also ordered one that Rote suggested to be placed at the Meanwell charger side, should be covered for now

 

[fechter]

Thanks guys for your replies, I have placed an order for this one:

https://www.aliexpress.com/item/50A-New-TK15-Professional-Precision-Battery-Tester-for-LiFePO-Coulomb-Counter-Free-Shipping-with-Tracking-Number/32702066121.html

I have several of those and I really like them. You can program in the pack capacity and that sets the scale for the bar graph and % remaining. You can program the capacity to be slightly less than the actual capacity of your pack if you typically only charge to 90%. If you leave the over and under voltage settings at zero, they are disabled (recommended). If you mount it between the pack and the BMS, it will count backward during charge and reset itself. If you have it only on the discharge side, you can reset it by a single long button press.

 

[wturber]

Thanks guys for your replies, I have placed an order for this one:

https://www.aliexpress.com/item/50A-New-TK15-Professional-Precision-Battery-Tester-for-LiFePO-Coulomb-Counter-Free-Shipping-with-Tracking-Number/32702066121.html

And I have also ordered one that Rote suggested to be placed at the Meanwell charger side, should be covered for now

I dunno. The label's upside-down. But if you are ok with that ... :^)

 

[fechter]

I dunno. The label's upside-down. But if you are ok with that ... :^)

Ah, you know that Aliexpress stuff, what you get never looks like the picture. :wink:

 

[hcrider]

I've been using a Watts-Up meter on each of my bikes, both running up to 58 volts. They work well, showing total watt hours and amp hours used on a ride, as they dynamically display watts and amps being consumed. They also record peak watts, peak amps, minimum volts. The displays are very readable in daylight. I'm happy with my purchase.