How to determine battery % charge off-bike

[ExFire]

The Step-Thru owner's manual (pg. 14) suggests keeping/charging the battery in a "room temp (+/- 10 degrees)"
dry environment, at about 75% charge, if not riding for some days. Then charge to 100% when preparing to ride.

The manual (same page) suggests charging the battery "inside", in the given temperatures.
Unless one wishes to have the whole bike in the house, the battery will be detached to meet these storage/charging conditions.

With the battery not connected to the display panel on the bike, I assume that if the equivalent voltage equalling 75% charge is known, a volt-meter could be used to monitor the % charge.

Does anyone know to which of the multi-connection points on the battery the volt-meter should be clipped to take this reading, ...and what voltage would indicate the 75% charge?

 

[jaizon]

That takes care of one.

Assuming the configuration for your plug is the same as mine (3 pins), mine is black at 12 and red at 6. If you get negative voltage readout, reverse the voltmeter wires going in.

 

[Taylor57]

The Step-Thru owner's manual (pg. 14) suggests keeping/charging the battery in a "room temp (+/- 10 degrees)"
dry environment, at about 75% charge, if not riding for some days. Then charge to 100% when preparing to ride.

The manual (same page) suggests charging the battery "inside", in the given temperatures.
Unless one wishes to have the whole bike in the house, the battery will be detached to meet these storage/charging conditions.

With the battery not connected to the display panel on the bike, I assume that if the equivalent voltage equalling 75% charge is known, a volt-meter could be used to monitor the % charge.

Does anyone know to which of the multi-connection points on the battery the volt-meter should be clipped to take this reading, ...and what voltage would indicate the 75% charge?

Your XP has a function on the display that will show you voltage fyi

 

[ExFire]

Your XP has a function on the display that will show you voltage fyi

Yes thanks,
...but not when the battery is off the bike. [Kept in the house, maybe for months(winter) to meet owner's manual suggested storage conditions.]

 

[ExFire]

View attachment 65373

That takes care of one.

Assuming the configuration for your plug is the same as mine (3 pins), mine is black at 12 and red at 6. If you get negative voltage readout, reverse the voltmeter wires going in.

Thanks for chart.
Lectric Step-Thru has 5 "pins"(blades) on bike frame to connect w/battery.

 

[Jeff F]

This photo was sent to me when Lectric wanted me to test voltage of a battery giving me issues. Notice the plus, and minus beside those leads.

 

[Taylor57]

This photo was sent to me when Lectric wanted me to test voltage of a battery giving me issues. Notice the plus, and minus beside those leads.


View attachment 68560

Should the positive be in the negative for the test?

 

[tomjasz]

Should the positive be in the negative for the test?

It really doesn't matter. Probes in the wrong polarity will just show a minus sign with the voltage display. It's also a good way to sort neg from pos.

 

[ExFire]

This photo was sent to me when Lectric wanted me to test voltage of a battery giving me issues. Notice the plus, and minus beside those leads.


View attachment 68560

Thanks Jeff, ...very helpful.

Makes me feel a bit "Duh!" for not looking more closely at the battery markings. :-0

I would have put the red lead in the "plus" mark, though.

Thomas, Good point.
(Did anyone ever tell you that you look like a fish?)

 

[Jeff F]

Should the positive be in the negative for the test?

I wondered about that too. When I check the voltage I have the red lead on the positive, and so forth.

 

[Jeff F]

Thanks Jeff, ...very helpful.

Makes me feel a bit "Duh!" for not looking more closely at the battery markings. :-0

I would have put the red lead in the "plus" mark, though.

Thomas, Good point.
(Did anyone ever tell you that you look like a fish?)

You are welcome, and when I check my batteries I do have the red on positive

 

[tomjasz]

A multimeter is invaluable. Many Chinese kits use blue and brown, rather than red and black. If on the wong poles you'll see a - minus before the numbers. Very useful!

 

[info4johng]

How does the voltage meter measurement vary from the voltage reading on the XP controller screen? Thanks, John

 

[Jeff F]

How does the voltage meter measurement vary from the voltage reading on the XP controller screen? Thanks, John

In my case there was only about a 1.2 volt difference between my meter, and the XP controller screen

 

[Sierratim]

Probably voltage drop across some electronics between the battery terminals and the controller screen; 2 diodes = 1.2V drop for example.

 

[info4johng]

Thanks you all for your reply. I just checked my XP and I get the following static measurements:

Multi-meter = 49.6 v
Controller = 50.4 v

I typically ride only 5-10 miles per day (every day) so I only charge to 70-80%. I am pleased to see that the controller measured voltages is within 1.6 % of the multi-meter and that the controller seems to be measuring high as I am trying to protect my battery from extended periods at voltages over 80 % (except during days when a charge to 100 % for an extended ride).

John G

 

[Two Sons]

I attempted to test my battery's voltage using a multi-meter and couldn't get a reading. I tested other batteries with the multi-meter and was fine, and also installed the battery in the bike and it read 50.4 volts. Can't understand why I'm not getting a reading using the meter to test the bike's battery. Anybody else encounter such an odd thing?

 

[ExFire]

I attempted to test my battery's voltage using a multi-meter and couldn't get a reading. I tested other batteries with the multi-meter and was fine, and also installed the battery in the bike and it read 50.4 volts. Can't understand why I'm not getting a reading using the meter to test the bike's battery. Anybody else encounter such an odd thing?

Exactly. No reading on either of 2 (Step Thru)batteries, tested with working meter, set on 300v. range, 2 days ago. Both batteries showed over 50 volts afterwards when installed in bike. Used contacts marked + and - on batteries. Curious, ( I note that several posters in this thread mention readings taken with meters ...Howdjadoit?) Comments welcome! :-0

TwoSons - Standard XP, or Step-Thru battery? My batteries have the +/- marks on different contacts than shown in the photo above in this thread.

 

[Gionnirocket]

Exactly. No reading on either of 2 (Step Thru)batteries, tested with working meter, set on 300v. range, 2 days ago. Both batteries showed over 50 volts afterwards when installed in bike. Used contacts marked + and - on batteries. Curious, ( I note that several posters in this thread mention readings taken with meters ...Howdjadoit?) Comments welcome! :-0

TwoSons - Standard XP, or Step-Thru battery? My batteries have the +/- marks on different contacts than shown in the photo above in this thread.

You can try different contact points on the battery if it has more than two. If it does typically the outer two are the main contacts but it's not written in stone. Also make sure to switch the battery ON if it has a switch. Lastly your probes might be too thick or too short to reach the contacts past the plastic. I have to use very small screw drivers as probe extensions to reach the battery contacts on some power tool batteries I have.

 

[Grey Max]

I attempted to test my battery's voltage using a multi-meter and couldn't get a reading. I tested other batteries with the multi-meter and was fine, and also installed the battery in the bike and it read 50.4 volts. Can't understand why I'm not getting a reading using the meter to test the bike's battery. Anybody else encounter such an odd thing?

Did you turn on the key first?