Lipo Battery Voltage Checker for eBike

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cgokey   1 W

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Lipo Battery Voltage Checker for eBike

Post by cgokey » Jul 01 2016 6:03pm

I was wondering what people are using for a Lipo Battery Voltage Checker for eBikes? Might be nice to have something with a wire that can go from the battery to the handlebars. But these look kind of interesting too:
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https://www.amazon.com/Floureon-Battery ... 2470955011
https://www.amazon.com/Integy-C23212-Vo ... 2470955011


Chris

cgokey   1 W

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Re: Lipo Battery Voltage Checker for eBike

Post by cgokey » Jul 01 2016 6:42pm

Also, how do these alarms work, as a little bit of reading I'm doing states that there is "load" voltage and "resting?" (no load) voltage. Under load the V can get down to like 3.3V or something but then after no load, it move back up to 3.7, 3.8, etc. So if there is only 1 alarm, wouldn't there be a lot of false alarms?

Chris

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motomech   1.21 GW

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Re: Lipo Battery Voltage Checker for eBike

Post by motomech » Jul 01 2016 6:59pm

I don't care much for those alarms. For one thing, they draw enough current that they can't be left connected when the bike is parked, not even for an hour. So every time before the ride they have to be connected(with the annoying screeching).
For use as a Low Voltage Alarm, they are a compromise, as you pointed out, due to Voltage sag. A "hard" Low Voltage Cutoff(LVC), usually in the controller, is a much better way to go. They are fool-proof.
As far as "displays" are concerned, if that is what you are asking about;
Although I started off with a Cycle Analyst, all I run these days is a Volt meter and my fav. is this one';
http://lunacycle.com/batteries/gauge/lu ... age-meter/
It is very flat and draws so little, it can be hooked up all the time.
It's flat form factor works very well for me because it fits inside the little clear plastic pouch that most sm. "over-the-frame saddle bags have. Here are a pair;
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'11 Motobecane Fathom team, Bafang SWX02-13T, 14S (54V) LiPoly, 9-FET 17A controller. Schwalbe Marathon's, 24 to 25 MPH.
Hobie Passport Kayak w/ Watersnake 18# motor, 12S LiPoly (46V) to golf cart 12V converter, 4 mph

cgokey   1 W

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Re: Lipo Battery Voltage Checker for eBike

Post by cgokey » Jul 01 2016 9:47pm

motomech wrote: For use as a Low Voltage Alarm, they are a compromise, as you pointed out, due to Voltage sag. A "hard" Low Voltage Cutoff(LVC), usually in the controller, is a much better way to go. They are fool-proof.
What is the LVC set to in the controllers? Is it pretty standard and therefore protect the lipo battery from reaching too low of voltage?

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wesnewell   100 GW

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Re: Lipo Battery Voltage Checker for eBike

Post by wesnewell » Jul 02 2016 12:22am

I just use one of these for pack voltage.
http://www.ebay.com/itm/RED-DC-Voltmete ... 1405804645
Need Advice? https://endless-sphere.com/forums/viewt ... =3&t=66302
Mongoose 26" Ledge 2.1 mtb bike $99, yescomusa.com 48V 1000W rear hub kit $200, Hua Tong 72V 40A controller $35, 10ah 24s lipo $217=~43mph, range=45 miles @ 20mph. 25K miles and still going strong.
Huffy Fortress 3.0 with MXUS 3000 4T motor, 24s lipo, 96V 60A controller. Total cost with extras <$700. Top speed ~50mph
My videos https://www.youtube.com/channel/UC0KW4U ... _G2wQhptMg

ScooterMan101   10 MW

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Re: Lipo Battery Voltage Checker for eBike

Post by ScooterMan101 » Jul 02 2016 12:59am

So where is the small / simple / inexpensive one that shows Amps used, and Watts ? along with the current voltage of the battery pack .
My first conversion ... Sold

viewtopic.php?f=3&t=71378&p=1077497&hil ... 1#p1077497

It's 2018 already, ( now 2019 ) lets get some real , improved e-bike / e-velomobile / e-motorcycle designs .

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wesnewell   100 GW

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Re: Lipo Battery Voltage Checker for eBike

Post by wesnewell » Jul 02 2016 1:30am

Need Advice? https://endless-sphere.com/forums/viewt ... =3&t=66302
Mongoose 26" Ledge 2.1 mtb bike $99, yescomusa.com 48V 1000W rear hub kit $200, Hua Tong 72V 40A controller $35, 10ah 24s lipo $217=~43mph, range=45 miles @ 20mph. 25K miles and still going strong.
Huffy Fortress 3.0 with MXUS 3000 4T motor, 24s lipo, 96V 60A controller. Total cost with extras <$700. Top speed ~50mph
My videos https://www.youtube.com/channel/UC0KW4U ... _G2wQhptMg

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dogman dan   100 GW

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Re: Lipo Battery Voltage Checker for eBike

Post by dogman dan » Jul 02 2016 6:32am

For a decently accurate checker of all the cells in your pack, get the Cellog 8

This is used at the house, to see if packs are balanced. Pretty accurate compared to the alarms.

Once you know which pack in your whole assembly has the lowest capacity, then you can put one of those cheap alarms on just that pack, when you think you will need it. Not all the time, but when you will beat that pack like a bad dog.

You may be out on the road, and need to wring 99.8% of your capacity out of the pack, or maybe you meant to return sooner, and are now worried about making it home. Once you are in limp home mode, the beeping will tell you to ride slower, and slower, and slower as you get into that last 1% of capacity.

So what I'm saying, when the voltage under load gets low enough, it start cheeping, you slow down, and it stops for a bit.

Set the thing for pretty low, when used like this. Like 3v per cell.

Another way to use one, just set it to 3.7v or so, so you get a warning that you are near the end, under load. When it keeps cheeping when stopped, you are now at 3.7v resting, and should be home if you want to leave some capacity in there.

But once you get a watt meter, or whatever bar mounted pack voltage meter, you can just watch that for the voltage that is 3.7v per cell, for the whole pack.

I love the cycle analyst, and have 4 of them. But that luna cycle meter looks great for just a voltmeter.

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DrkAngel   100 GW

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Re: Lipo Battery Voltage Checker for eBike

Post by DrkAngel » Jul 03 2016 5:27pm

See - eBike Toolbox Bargains
Just found a nice meter - tool
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