JTL
10 W
I don't currently have any kind of watt meter. Do most ebikers have one? I don't want or need a CA but I was thinking about an ebay cheapo or a less cheapo Watts Up. Any suggestions?
Watt Meters
- Thread starter JTL
- Start date
dogman dan
1 PW
The cheap blue watt meters cost about 12 bucks these days, and are quite adequate if you don't want to mount it on the bars. It sounds like a pain to stop to look at it, but really it's not.
A bar mounted watt meter like the CA, is still the only way to go for learning to ride the bike for max distance. Not really max efficiency, but max combination of speed, your pedaling, the terrain and weather, etc, to go farther. The ca does a continuous watthours per mile display, that is priceless when you need maximum range, without going to maximum pedaling effort.
You can of course stop, look, and make the mental calculations as you go, with a cheap blue meter.
A bar mounted watt meter like the CA, is still the only way to go for learning to ride the bike for max distance. Not really max efficiency, but max combination of speed, your pedaling, the terrain and weather, etc, to go farther. The ca does a continuous watthours per mile display, that is priceless when you need maximum range, without going to maximum pedaling effort.
You can of course stop, look, and make the mental calculations as you go, with a cheap blue meter.
Ykick
1 GW
On my simple bikes, after I’ve learned their power usage it really isn’t gonna change much. Therefore, I temporarily insert RC type type power meters, ride for a while and observe what the system does. Perform any tweaks needed and eventually just remove the meter and put it back on my charger station.
Be aware inserted power meters will require connector ecosystem. That’s something to consider along with your choice of power meter. Good solid power connections and wire make it all possible.
Be aware inserted power meters will require connector ecosystem. That’s something to consider along with your choice of power meter. Good solid power connections and wire make it all possible.
JTL
10 W
Ykick said:
Do you monitor the info while you are riding? I think I read that some of the cheap meters have a problem with accurate data if the meter is not real close to the battery. It would be nice to be able to monitor the charger. Thanks
JTL
10 W
dogman dan said:
Thanks for the info.
docw009
1 MW
I have a pair of the cheap ebay wattmeters. I was surprised how well they work and both give reproducible data, with one exception. With my initial trial on a fully charged 52 volt battery, the voltage readings were over 60 volts, way too high, and the watts data looked way too low. Could be they weren't calibrated to run so high, or my connectors were loose.
Since they are mounted near my batteries, I have to stop and look. I mainly used them to see what kind of mileage I get for different speeds on my bikes. It does help to know how your power draw changes with average speed, but after you know that, you know it. It's also a useful method for assessing the health of a battery.
Since they are mounted near my batteries, I have to stop and look. I mainly used them to see what kind of mileage I get for different speeds on my bikes. It does help to know how your power draw changes with average speed, but after you know that, you know it. It's also a useful method for assessing the health of a battery.
Ykick
1 GW
JTL said:
Long power wire is the problem for remote mounting, not what you pay for the meter. Use large enough gauge wire and good connectors 3-4ft wire isn't gonna make significant difference.
However, once you go through all of that trouble you'll probably find the RC power meters are too small to read under most riding conditions. Even the slightest vibration makes them very difficult to see under way.
You might be missing what they're designed to do? RC power meters are often installed temporarily into planes or RC vehicles then sent out to fly or do what they do. When they return, you make note of min/max and amount values for that particular mission.
That's how I use RC power meters on my simple ebikes. Insert in a logical place, usually near the battery, go ride and retrieve pertinent info when stopped.
Is that ideal? Maybe not? That's why we've got the CA (cycle analyst) for an actual dashboard that provides the power data and more. Using a compatible controller and DP (direct plugin) CA you won't even need to bother with power wiring and connectors. But, it does come at a price well above that of RC power meters.
MrDude_1
100 kW
JTL said:
After being spoiled with a CA, I feel blind without one.
With one, I know my wattage being used (and can adjust as needed) but more importantly I know how much power I have consumed... then when I plug my bulk charger in, I know how much it rolled back.... that way I can keep track of where I stand.
A practical example for me: I go into town on surface streets, and plug in at a public outlet. I grab lunch and get a call from some friends. they want to go stop somewhere and I want to meet them there. do I have enough power to go there to charge?
with no meter, I could have just enough, plenty, or maybe there was a headwind or I was going faster or accelerated extra and I will end up short.
with a meter, i can glance at it and tell if I can go, or if I need to stay plugged in an extra 15 mins or so.
without a meter, i cant tell if my charger is working at all.. or how hard its working, or how charged I am. then I get worried about my range. then its less fun.
if you think the CA V3 costs too much, you can get the V2 pretty cheap... although the throttle with the V3 is awesome if you are willing to learn and use its features.
JTL
10 W
Ykick said:
This may be a stupid question but what are you measuring. It will no doubt show remaining V which I can get with my multimeter. Do you check Ah at the beginning and then at the end and multiply by remaining V to get expended WH? Anything else? For the price I think I will just get one since they are so cheap. I am waiting for my battery and charger from Em3ev then I will know what type of connectors I need. I assume to connect the meter I just need to put in a Y with the matching type of connector on both the battery and the controller. I have the BBSHD, not that it matters.
dogman dan
1 PW
FWIW,, I did open up and tweak my cheap wattmeter, so it read voltage correctly. The watts seemed ok compared with known to be calibrated CA. I don't recall if that can be adjusted inside those cheap meters or not. I only had the one, and it died in a few months. ( I fed it 72v by mistake once) Now I have 4 CA's, so usually I have one on every bike up and running.
To get your fuel gauge, you first charge full, then discharge by riding till it's 100% empty. when the bms stops it, If you have one. Watch at the end, when the battery cuts off, you lose your data on the cheap meter.
Now you know your real world AH or WH. For the way you ride, on your bike. Your 10 ah pack may put out 9.2 ah, or whatever. Now you know what half a tank is, etc. Half of 9.2 is 4.6ah. Or call it 8 ah, and know if you turn for home with 4 ah used, you make it with a big reserve.
The meter will display AH used, it will display watts currently flowing, it will display WH used. It can read the battery flow going out, or you can put it on a charger and read what's going in. Just a matter of plug compatibility to do that. Make adapters for the charger plug is the best way to go, unless it's just a naked pack.( no bms).
Once you know what your performance is,, like Ykick says, you don't need it on the bike anymore. I hardly need my CA to know I'll make the usual 10 mile round trip to the grocery for example. But I sure love a CA when I'm planning a ride of 40-80 miles. 99% of what I use my CA for is knowing I did actually charge the battery. Hey,, lookee there, 54.6v. Before I had any watt meter, I got screwed a few times by poor plugs on chargers. Ride off thinking I had 15 ah, only to find out 10 miles from home I'm empty. Whoops. That's 10 miles all uphill, from home. :lol:
To get your fuel gauge, you first charge full, then discharge by riding till it's 100% empty. when the bms stops it, If you have one. Watch at the end, when the battery cuts off, you lose your data on the cheap meter.
Now you know your real world AH or WH. For the way you ride, on your bike. Your 10 ah pack may put out 9.2 ah, or whatever. Now you know what half a tank is, etc. Half of 9.2 is 4.6ah. Or call it 8 ah, and know if you turn for home with 4 ah used, you make it with a big reserve.
The meter will display AH used, it will display watts currently flowing, it will display WH used. It can read the battery flow going out, or you can put it on a charger and read what's going in. Just a matter of plug compatibility to do that. Make adapters for the charger plug is the best way to go, unless it's just a naked pack.( no bms).
Once you know what your performance is,, like Ykick says, you don't need it on the bike anymore. I hardly need my CA to know I'll make the usual 10 mile round trip to the grocery for example. But I sure love a CA when I'm planning a ride of 40-80 miles. 99% of what I use my CA for is knowing I did actually charge the battery. Hey,, lookee there, 54.6v. Before I had any watt meter, I got screwed a few times by poor plugs on chargers. Ride off thinking I had 15 ah, only to find out 10 miles from home I'm empty. Whoops. That's 10 miles all uphill, from home. :lol:
JTL
10 W
dogman dan said:
More good info..Thanks.
KINNINVIEKID
1 kW
I found that the cheap blue meters never lasted very long but the GT power meters have done a couple of years so far.
They were on my bike for 18 months till I bought a CA and since then are connected to my bulk charger.
http://www.ebay.co.uk/itm/G-T-POWER...124881?hash=item4654f61811:g:5LIAAOSwTA9X2Q0h
They were on my bike for 18 months till I bought a CA and since then are connected to my bulk charger.
http://www.ebay.co.uk/itm/G-T-POWER...124881?hash=item4654f61811:g:5LIAAOSwTA9X2Q0h
JTL
10 W
KINNINVIEKID said:I found that the cheap blue meters never lasted very long but the GT power meters have done a couple of years so far.
They were on my bike for 18 months till I bought a CA and since then are connected to my bulk charger.
http://www.ebay.co.uk/itm/G-T-POWER...124881?hash=item4654f61811:g:5LIAAOSwTA9X2Q0h
Thanks for the heads up!
Ykick
1 GW
GT meter is the RC meter I use plus I have 3 CA’s too.
But I can’t stress enough that if you’re going to measure “power” with an RC meter you’re going to need to “insert” it into the battery-to-controller wiring.
Y or parallel connection will only provide voltage and no power data. You need a series connection or ability to “insert” the meter into the power wiring.
Some of us prefer APP (Anderson Power Pole) for these things. There’s many other fine choices such as XT60/90’s, Deans, Bullets, etc.
APP’s really need a seemingly expensive crimp tool. They can be assembled without the correct crimp tool but it’s a hack job.
Most of the other type connectors require soldering and not just small PCB soldering but irons/tips which can deliver a large mass of heat to heavy gauge wire and workpieces.
Check into RC or HAM radio vendors for connectors and wiring which can elegantly handle the Amps we’re working with. Steer away from automotive wiring and connectors - generally not up to the task, IMO.
Some of that fine stranded silicone insulated wire is good stuff to keep on hand too. Maybe various size heat shrink depending on the type of connector you settle on?
But I can’t stress enough that if you’re going to measure “power” with an RC meter you’re going to need to “insert” it into the battery-to-controller wiring.
Y or parallel connection will only provide voltage and no power data. You need a series connection or ability to “insert” the meter into the power wiring.
Some of us prefer APP (Anderson Power Pole) for these things. There’s many other fine choices such as XT60/90’s, Deans, Bullets, etc.
APP’s really need a seemingly expensive crimp tool. They can be assembled without the correct crimp tool but it’s a hack job.
Most of the other type connectors require soldering and not just small PCB soldering but irons/tips which can deliver a large mass of heat to heavy gauge wire and workpieces.
Check into RC or HAM radio vendors for connectors and wiring which can elegantly handle the Amps we’re working with. Steer away from automotive wiring and connectors - generally not up to the task, IMO.
Some of that fine stranded silicone insulated wire is good stuff to keep on hand too. Maybe various size heat shrink depending on the type of connector you settle on?
JTL
10 W
Maybe I have this wrong but my plan was to put a pigtail on the wires to the controller. Two actually one in and one out, maintaining polarity. Gets to be a lot of connections to deal with. Does this sound correct. Maybe "Y" was not the right term.
motomech
10 MW
The Wattmeter needs to placed in series between the batt. and the controller, not paralleled.
I have had about every kind of instrumentation from a CA on down and these days I just use a Voltmeter, it's all I need w/ LiPoly, as it's discharge rate is very linear..
W/ a new controller, I'll temporarily install a Wattmeter to ck. the performance of the controller.
The thing about meters, if they are LED, they need a way to turn them off, either at the batt. or at the meter or it will deplete the batt.. LCD meters that have back lighting, need to have a way to turn off the light.
Luna Cycles is a good source for meters, I really like their flat Voltmeter.
Here are two of them(I have two packs)in a clear pouch on a sm. over-the-frame bag. Push a button and they lite for a minute or so. The LCD display doesn't draw enough to be factor;
I have had about every kind of instrumentation from a CA on down and these days I just use a Voltmeter, it's all I need w/ LiPoly, as it's discharge rate is very linear..
W/ a new controller, I'll temporarily install a Wattmeter to ck. the performance of the controller.
The thing about meters, if they are LED, they need a way to turn them off, either at the batt. or at the meter or it will deplete the batt.. LCD meters that have back lighting, need to have a way to turn off the light.
Luna Cycles is a good source for meters, I really like their flat Voltmeter.
Here are two of them(I have two packs)in a clear pouch on a sm. over-the-frame bag. Push a button and they lite for a minute or so. The LCD display doesn't draw enough to be factor;
JTL
10 W
motomech said:
pos to neg, ie black to red . Seems counter intuitive but I don't know electronics. Thanks.
motomech
10 MW
Sorry, maybe I should have said in-line;
Red from batt. into meter red, red from meter, to controller red
blk. from batt. into meter blk., blk. from meter to controller blk.
Red from batt. into meter red, red from meter, to controller red
blk. from batt. into meter blk., blk. from meter to controller blk.
JTL
10 W
motomech said:
That makes sense.
TheBeastie
1 MW
I am putting one of these on my electric quad bike project..
http://www.ebay.com/itm/152217005430?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
I understand why these can be unatractive if your trying to keep your wiring on your ebike clean and simple.
http://www.ebay.com/itm/152217005430?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
I understand why these can be unatractive if your trying to keep your wiring on your ebike clean and simple.
RLT
10 kW
After the sun destroyed the LCDs on two of the RC type watt meters within days on my electric 3 wheel cart/pickup truck, I installed one of these wireless watt meters (I also have some of them on my solar system to remotely monitor individual panel groups and charge controllers where I didn't want to pay the big bucks for the factory remotes.).
http://www.ebay.com/itm/DC-0-120V-0...cent-Battery-Monitor-Watt-Meter-/171806357411
The meter display itself can run all day on a small 2S Lipo or Li-Ion pack or even a 9V alkaline battery. If you don't need to constantly monitor conditions, it doesn't even need to be mounted. Stick it in your pocket and just pull it out when you want to check.
They are even programmable to control a relay for voltage / current / time shutoff protection.
They also have 200 Amp units for a couple bucks more.
http://www.ebay.com/itm/DC-0-120V-0...cent-Battery-Monitor-Watt-Meter-/171806357411
The meter display itself can run all day on a small 2S Lipo or Li-Ion pack or even a 9V alkaline battery. If you don't need to constantly monitor conditions, it doesn't even need to be mounted. Stick it in your pocket and just pull it out when you want to check.
They are even programmable to control a relay for voltage / current / time shutoff protection.
They also have 200 Amp units for a couple bucks more.
JTL
10 W
If I put a meter inline between the battery and the controller I could simply unplug it and reconnect my wires direct without the meter when I don't need it. I have an extra xt90 set but they are not the "s" style. My battery to controller connection will have the "s" style according to em3ev and they insist on keeping it that way. My guess is that if I use a non-s male into an "s" female I will negate the pre-charge feature. Is that a fair guess?
Jon NCal
1 kW
No, the pre-charge resistor is in the female side marked with the green markings. It will function properly with the non-S male XT90.JTL said:
JTL
10 W
Jon NCal said:
I thought that perhaps the male connector was slightly longer than normal allowing it to pass through the resistor and make full contact after the pre-charge.
JTL
10 W
I guess the battery I am receiving from em3ev has xt90s connectors on the battery to controller, but Andersons on the batter to charger. If I want to add a watt meter to monitor the charge and also use it to monitor the battery during use I am going to have to change some things around. Where is the best place to get connectors?
