Cheap Voltage Meter / Load Tester Suggestions?

[Logos]

I have a X-TREME XB-300Li
http://www.x-tremescooters.com/electric_bicycles/xb300li/xb300li.html

I have two 12v 7ah sla batteries hooked up in a series.And I charge then individually with some computer battery backup surge protectors.But the Battery Level Display is just a a few red leds.I want something more accurate. So a voltage meter and load tester are essentially the same things right?heres the voltage meter I was thinking of getting this Car Voltage Meter / In-Out Thermometer / Clock
http://www1.jaycar.com.au/productView.asp?ID=XC0116
since it would basically become a gas(electric) gauge for my bike.Im guessing it can handle up to 24volts.Not sure.The reason Id like to get that is because it functions as a constant load tester with other features, so I dont have to buy a Innova 3320 Auto-Ranging DMM
http://www.equus.com/Product/3320/Auto-Ranging-DMM

I mean it seems liek the car volt meter does the same as these fancy expensive meters
http://www.ebikes.ca/store/store_CA.php

But Maybe car batteries are only 12v and the car volt meter wont read beyond 12v?

 

[amberwolf]

The JC thing definitely doesn't do what the CA does. It appears to only measure voltage, and not any of the other things the CA can.

For SLA, that still might be ok, as long as you remember what voltage means what state of charge (how much power you have left).

 

[Logos]

Yes Im aware The Cycle Analyst (formerly called DrainBrain) has lot of features,but its $120.And Im looking for bare minimum need to have features, and the Car Voltage Meter / In-Out Thermometer / Clock has quite a few for only $25

in-car voltage and temperature meter features an EL-Blue backlit LCD which is constantly illuminated when the power is present. The unit can be hard wired for permanent connection.

Two LR44 button cells keep the clock powered when the power is switched off.
Two temperature sensors monitor both the inside and outside temperature , with the external sensor attached to a 3m length of cable. Min and max displays are recorded for both the inside and outside temperature sensors for ongoing reference.

A green LED advises you if the battery level is good, but it will flash and an audible warning will sound if the battery voltage is critically low. The LCD, however, will indicate a more accurate reading if it's required. An ice warning is also available if you live in a cold area (based on zero temp, monitored by the outside sensor). A clock and calendar are also featured.

if you have another suggestion thats cheaper than the Cycle Analyst, please let me know or link to it here.

 

[dnmun]

the reason everyone uses a cycle analyst is because there is nothing else to compare to it in terms of what it does.

to me the most important is remembering the last measurements in memory so that when the bike breaks down on the road then you have something to inform you of what the problem is. without it there is no way to guess your way into understanding why the bike just broke down.

if someone could make something and get it to perform the same task, it would not cost any less.

also it is part of how we can help support the guy who made this place free from evil.

 

[dogman dan]

Affordable voltage meters exist. Here is one example. We have a thread here about it in reviews I think. You want the two wire type, so it powers up on any voltage you happen to have, in this example, up to 120v. Avoid the three wire ones, they need a seperate power supply to run them.



http://www.ebay.com/itm/Waterproof-Digital-Panel-Meter-DC-15-120V-Red-LED-24V-Battery-Voltage-Voltmeter-/281026600955?pt=LH_DefaultDomain_0&hash=item416e7d9ffb

Defintiely not close to a CA, but a LOT better than a "you just ran your battery too low again" indicator.

Relatively cheap wattmeters exist too, that go to about 60v. Look at the RC hobby websites for them, Hobby King etc.

A wattmeter is one of the most valuable functions of a CA. It's the true gas guage for an EV. By using a wattmeter, you can determine what the true capacity of your batteries is. The load can be a light or heating element, or your bike motor. Once you know how many watthours you have avaliable, from fully charged to the point you wish to stop, then you can ride along and by looking at your current wh used, know exactly how many wh you have remaining.

However, the way lead acid batteries slowly lose voltage along the whole ride, you can make a pretty good guess about remaining capacity with that less than ten bucks voltmeter.

 

[Logos]

@ Amberwolf
This is my first Electric bike so Im not trying to spend alot of money on this,just turn it into a good daily rider with bare minimum necessities.The Cycle Analyst is a complete overkill for a sealed lead acid battery in my situation.So your right it would probably suit my needs.The car voltage meter tells me the voltage and warns me when its low.Which is the bare minimum of what I need.And only costs about $25.

@ dnmun
while your right most alternatives to the cycle analyst dont store the data after you lose power,If I already figure out what voltage and amperage levels I need to stay above,then its just a quick way to gauge how soon i need to charge my batteries.Since this is just a bike i use to get to and from work on a daily basis.But the devices I found below already have the feature of storing data as long as you get an external power source,along with quite a few features the cycle analyst has

@ dogman
The voltage gauge you linked to is better than what I have but Id rather spend an extra $10 and get alot more features.But your right a watt meter is what I think Im gonna go with.Heres the ones I found

Turnigy 130A Watt Meter and Power Analyzer $23.99
http://www.hobbyking.com/hobbyking/store/__10080__Turnigy_130A_Watt_Meter_and_Power_Analyzer.html
Turnigy 7 in 1 Mega Meter $39.99
http://www.hobbyking.com/hobbyking/store/__22631__Turnigy_7_in_1_Mega_Meter_.html

But Im still curious if anyone can tell me more about the car voltage meters I have looked at?I mean all cars,trucks,motorcycles,and other vehicles use different batteries.So I can also search for those types of gauges as well right? like this one

INTELLITRONIX LED DIGITAL VOLTMETER GAUGE
http://www.jcwhitney.com/led-digital-voltmeter-gauge/p2024096.jcwx?filterid=c27290u0j1
They feature microprocessor controls with peak voltage recall. Accurate, bright and intelligent all in one.
7 - 24 Volts with high voltage recall.
2 1/16" Diameter
Choose from Blue, Green, Red or White LED with a black bezel.
Limited Lifetime Warranty

THANKS IN ADVANCE FOR EVERYONES HELP

 

[Skedgy Sky]

I put together my first e-bike about two weeks ago now (I'm still constantly working on it and waiting for parts to come in) but I bought Hobbyking's watt meter (the one for $25) and it works really well from the couple of times I've tried it on the bike so far. It's simple and tells me everything I wanted to know from when I went looking for one of these.
Also has the back-lit display (IN BLUE! ) so viewing it at night isn't a problem.

I can't comment on any of the other ones listed in the thread but I'd recommend Hobbyking's watt meter for the price.

 

[Logos]

can you link us to the exact model watt meter you bought?And what type of battery supply do you have?how do you power the watt meter?

 

[amberwolf]

It's probably this one:
http://www.endless-sphere.com/forums/viewtopic.php?f=3&t=13607

 

[Logos]

So alot of the Watt Meters I have found say they are for LiPo,LiFe,LiIo batteries. Can I also use those same ones for Sealed Lead Acid?

like this one?

http://www.ebay.com/itm/Digital-60V...racter_Radio_Control_Toys&hash=item3f1ad96860

 

[amberwolf]

Antyhing that is *just a meter* doesnt' matter what it's hooked to as long as you don't exceed the voltage limits of the device, or try to pull more power or current thru it than it is rated for.

Anything that is also a *charger* has to be able to work on the specific type of battery you want to use it on, or else you need to understand how to work around any limitations it might have in using it for something it's not intended for. That includes understanding the consequences of charging at different voltages or currents than the battery you want ot use it on was made to take, if it doesn't have a manual setting to let you set those correctly for your battery.

 

[dogman dan]

Better off to go with one of the ones that's just a wattmeter, or wattmeter and voltmeter.

A wattmeter of any kind beats just a voltmeter. A wattmeter tells you your watthours used, and once you know your battery's max wh, you know just where you stand.

A voltmeter lets you guess at the watthours, based on your voltage. But you can guess pretty darn close just by that once you know your bike well. I used to guess my battery level extremely close just by using an odometer once I knew my battery well.

 

[Logos]

I ended up ordering this http://www.amazon.com/gp/product/B008VOJP6M/ref=oss_product which only cost me $20.70 to my door and was sold by a US reseller.

I unhooked my led battery meter,but when I select the "watt" setting to view my all I can see is this

WAT 0.0A 24.68V
0.0W 0.0AH

Did I hook it up wrong?I wanted to see the Amp Hours and alot more info than the Voltage. So if my total voltage for the two 12v batteries gets down to 12v thats when I need to charge it again?since you shouldnt let a sealed lead acid get down to 10.5v by itself?

 

[Skedgy Sky]

I believe to measure current, amperage, and all the other stuff you have to have the wattmeter inline with your circuit. Just like when you measure voltage with a multimeter... you connect black to black, red to red... and you're not breaking the circuit you're measuring. If you measure Amps with a multimeter, you have to break the circuit and put the multimeter inline with the circuit to get an amp reading.

I think the same goes for the watt meter you ordered. You have to put it inline with your circuit which means connecting the batteries (source) on the left of the meter and the motor or motor controller (the load) on the right of the meter. If you only got one cable with the thing, you may want to cut the cable in two to connect it from each side of the meter.

http://1.bp.blogspot.com/_12Z4sKop594/Ss1OxvcH7oI/AAAAAAAAAaM/ll3-XzEkkDw/s400/WATTSUP-METER.jpg

 

[Logos]

Here are the instructions and diagrams that came with it

 

[amberwolf]

Did I hook it up wrong?I wanted to see the Amp Hours and alot more info than the Voltage.

Yes; I see no wires going into the right side of the meter (load). See Skedgy Sky's post above for the correct way.