60v 30ah brand new battery

Hi,
I am a proud new owner of a 60v 30ah battery. I have upgraded from a 48/20.(both lifepo4)soft pack 1p.
I recieved the battery today and took reading of 67/22. That opened my eyes because that high of voltage should = higher amp on 60/30. Charger cut off is 73.5 and measures 24 amp no load. So come to my supprise amps are not the same as AH.
I put the battery on the charger and it topped off in less than 10 min at 72.6/24.1.

Immediately I felt disscuraged. But am i incorrect in thinking a 60/30AH lipo battery should measure 30 amp fully charged?
One other question for users out there,
What do you think 1750 watts will do to a 1000 watt hub motor with 1500 watt controller max is 84v/45 amp
I'm using 12 gauge wire and also replaced hub stock motor wire with rated 1500 watt to internal 3 phase windings

thanks for your help

Lipo does not equal LiFePO4. Two different, but similar chemistries. You used both in your post to refer to your new pack. With LiFePO4, it is much harder to correlate a given voltage to a state of charge.

Amps (A) = An instantaneous charge or discharge rate.
Watts (W) = Amps * Volts
Amp Hours (Ah) = Average Amps for 1 hour

I'm not sure what you are measuring on the right side of the /. 72.6V ok. What is 24.1? It can't be Ah unless you fully discharge the pack and use Discharge Time and Average Amps to calculate Ah. Can't really be Amps either, that's a rate at a moment in time.

If this is a guess from a RC charger, have to take that as a guess until more data is known.

I'm not a motor guy yet. Others may have more comment. But 1750 watts on 1000 watt windings depends on what was behind the 1000 watt rating. If it is 1000W continuously, brief excursions to 1750W will likely work OK. I think the main measure is temperature, which requires a monitored temp sensor in the hub motor. Keep that at 120C or less, and you probably won't fry the motor.

thanks for your reply, It is a po4 and when purchased there rating was 60v/30AH fully charged at 73v.
fully noted i am a beginner i assumed the pack should measure near 73/30a fully charged.
Is this an incorrect assumption of the term 30AH.
And thank you for the rest of your input for what declares rating as well as burst or spike . I also believe Heat is your best measurment to eliminate failure when over-volting a hub motor.
Thanks again for your accurate and educated response

JamieWlcox said:

Immediately I felt disscuraged. But am i incorrect in thinking a 60/30AH lipo battery should measure 30 amp fully charged?

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How are you "measuring" this? There is no way to directly measure state of charge or capacity of a battery. It can only be estimated by either draining it completely then charging it fully and measuring the energy supplied by the charger; or charging it fully and draining it completely while measuring the discharge.
"30 amp fully charged" makes no sense, unless you're saying you connected a load after charging the battery and the highest discharge rate achieved was 30 amps (that seems unusual, since it would indicate that the pack can only provide 1C). A 30Ah lipo with 10C cells could provide 300 amps, for about 6 minutes.

so more than likely here just tell me i am stupid for thinking my volt meter can measure amps ,not just volts.
Why do they put amps on volt meters if there is no way to measure them

Voltage isn't directly related to Amp Hours. It can be an indicator or remaining capacity, but that isn't at all an exact science. Generally speaking, you fully charge a battery, then use what's called coulomb counting that monitors amps in/out over time calculating Ah used/added. Then at a defined fully charged voltage and rate, reset state of charge to 100%. Capacity in Ah is the Ah consumed when reaching full discharge voltage.

Capacity in amp hours is not a constant. The higher the discharge rate in amps, the lower the capacity in Ah. For example, in a normal deep cycle flooded lead acid battery rated at 225 Ah total, the 225 Ah rating is based on a 20 hour rate. When new, the battery will provide 11.25A for 20 hours. However at a 10 hour rate, it only provides 207 Ah total at 20.7A for 10 hours. At a 2 hour rate, only 146 Ah total which is 73A for 2 hours. This from a Trojan T105.

These specs are harder to find for lithium cells, but generally far better than my example at high rates of discharge. Most would provide the rated capacity, even at a 2 hour rate. And the difference between Ah capacity at 2 hour and 20 hour rates would only vary slightly. But discharge from 100% to 0% in 30 minutes instead of 2 hours, the capacity observed will be less for sure, and probably less than the advertised rating. If the cells are rated for that level of discharge, the capacity reduction would be small compared to traditional chemistries.

JamieWlcox said:

so more than likely here just tell me i am stupid for thinking my volt meter can measure amps ,not just volts.
Why do they put amps on volt meters if there is no way to measure them

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Not stupid, maybe a reasonable conclusion on the voltmeter since it looks that way. And, you CAN measure amps with the meter, but probably not anything close to 30 amps, since basically you'd need to put the meter leads in series with your battery, between the battery and controller (or other load). For most cheap meters, the max might be 10 amps, but I'm not sure the leads could take much more. With the right meter, you can measure amps (instantaneous), and over time (an hour), amp-hours.

Empty it and fill it up, or fill it up and empty it, and you can figure out the capacity of the battery; no other way to really tell, and it changes as the battery gets older.

so would both of you conclude that amps cannot be measured with out a load using a volt/amp meter.
Thanks for every ones response here i am going to be retiring for the night, and hope to have a more clear understanding of this in the future

JamieWlcox said:

so would both of you conclude that amps cannot be measured with out a load using a volt/amp meter.

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Correct, but you don't need a voltmeter to solve for amps with no load. Ohm's Law: E = IR (Volts equal Current times Resistance)

solve for current: I = E/R = 73.5/infinite = 0

If you are using your voltmeter, and its current inputs, and attaching that directly to your battery, then the "load" is your meter. It may have some protection built in to keep from frying, or short circuiting your battery and the ensuing fireworks.

Amps by definition are zero without a load.

Current flowing is what the unit measures.

Ah if that's what you mean, requires an Ah totalizer, aka coulometer, Ah meter,

also a subset of a proper Battery Monitor that estimates SoC.

All of these will also display the fluctuating Amps rate as well.

But that is **all** an ammeter shows.

If you are trying to read amps from a DMM, link to its manual or datasheet please.

I definitely like your equation to solve amps with no load I will look into this and try and educate myself prior to asking more questions thank you have a nice night

True. No load = 0 amps.

As previously mentioned, most meters are limited to 10A if directly inserted for measurement. Your meter has a spec, probably printed on it somewhere.

However, you can add a shunt, and measure load current using voltage. With the proper shunt, up to any practical amps value for an EV application. The specifics are here:

http://www.measurementest.com/2010/08/how-to-measure-current-using-shunt.html

The key to this and some of this discussion is understanding Ohms Law and Power equations. Lots of places to look on the net for an explanation.

BlueSeas said:

However, you can add a shunt, and measure load current using voltage. With the proper shunt, up to any practical amps value for an EV application.

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I was using one of these, shunt included. It was nice (for $15), since it kept the watt-hours in memory, even after disconnecting the battery. Some others don't. Stopped using it because it stopped registering watt-hours, I think when I turned on regan in my controller settings.Something got fried I guess. I couldn't find anything warning against it, but I've noticed some meters will be explicit with +/- ranges in their specs. Apparently this one couldn't handle the reverse current.

I find useful to measure effective avg W/h in riding conditions. I mean, how many W/h consumed per km. I measure it when charging, repeatedly to have an average. Then I measure it again if I notice my range dropping because of battery wear. Most of the time, I notice a power drop before a range drop. That is because I am pulling close to the peak C rate of my cells day after day, so I need to buy new RC lipo pretty often.

Long ago, I was just abusing them until they start to smell.
Now I measure temp, to know when they are getting weak, and to order new ones before puffing them. :wink:

E-HP said:

I was using one of these, shunt included. It was nice (for $15), since it kept the watt-hours in memory, even after disconnecting the battery. Some others don't. Stopped using it because it stopped registering watt-hours, I think when I turned on regan in my controller settings.Something got fried I guess. I couldn't find anything warning against it, but I've noticed some meters will be explicit with +/- ranges in their specs. Apparently this one couldn't handle the reverse current.

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That's sad news. I have this unit too and was hoping to use it with my DD hub motor.
Any thoughts about bidirectional meter like this?

silence said:

E-HP said:

I was using one of these, shunt included. It was nice (for $15), since it kept the watt-hours in memory, even after disconnecting the battery. Some others don't. Stopped using it because it stopped registering watt-hours, I think when I turned on regan in my controller settings.Something got fried I guess. I couldn't find anything warning against it, but I've noticed some meters will be explicit with +/- ranges in their specs. Apparently this one couldn't handle the reverse current.

Click to expand...

That's sad news. I have this unit too and was hoping to use it with my DD hub motor.
Any thoughts about bidirectional meter like this?

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I use the same $15 meter in all my packs. The front motors of my trikes have regen on 100% of the time and I even have the meters turned 'on' when recharging. When recharging or regen operation the meter does not work in reverse, but I've never had one fail due to how I use them. I have had meters fail for other, unknown reasons (maybe they just didn't like living).

I use the same $15 meter in all my packs. The front motors of my trikes have regen on 100% of the time and I even have the meters turned 'on' when recharging. When recharging or regen operation the meter does not work in reverse, but I've never had one fail due to how I use them. I have had meters fail for other, unknown reasons (maybe they just didn't like living).
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Ya, definitely can't tie it to regen, only the observation that it stopped working shortly after turning it on. At least it worked long enough to gather the data I wanted about the motor and battery performance.

Apparently a good one
https://powerwerx.com/watt-meter-analyzer-inline-dc-powerpole
Would like suggestions for other in-line type, with decent ampacity, not too expensive

Counting coulombs, totalizing Ah/Wh, not just ammeters

Lower cost would be great as long as two-way & reasonably robust.

For expensive ones, adjustibility to use shunts at 100A up to 1000A.

Ok ah is like a 5gal bucket or a 10 gal bucket or 30 gal bucket so it's capacity or amount. Amps is how big the hose is like a garden hose or fire hose or volume of use. Volts is the pressure . I hope that's right ? Maybe someone can help me with volts haha.
Check the voltage of your charger and a link to your battery.

999zip999 said:

Ok ah is like a 5gal bucket or a 10 gal bucket or 30 gal bucket so it's capacity or amount. Amps is how big the hose is like a garden hose or fire hose or volume of use. Volts is the pressure . I hoe that's right ?

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Yes.

Amps and watts are the flow rate, "per second" already part of the unit, vary instantaneously, think of time on the X axis, Amps or Watts on the Y axis.

Ah and Wh is the area under the line, think of calculus, doing a definite integral.

So capacity of a battery, static quantity. Also amount used per time period, so

Ah per 24 hours
Wh used up in twenty minutes.

Yes volts is like pressure, only potential. Work gets done only when current flows.

One thing that makes things simpler, is to stop thinking about amp hours and convert to thinking in watt hours.

Amp hours is capacity at a given voltage. Watt hours is amp hours x voltage, the result of the AH calculation. Calculations are guestimates. A real watt meter can measure your real amps load, and count the real watt hours as they flow into the controller.

If nothing else, you stop confusing amps with amp hours when you get rid of thinking about AH.

You will need to get a watt meter to read your real world amps load, as you ride. They don't cost all that much, but some of the cheaper ones max out at 60v.

Your motor, if its given a big enough load, will overheat, and eventually melt. typical "1000w" kits come with 500w rated motors. They easily take 1500w. But your setup, if it can give 45 amps of 72v will be over 3000w. At that rate, it will overheat in 30-45 min, if you keep riding 40 mph for that long.

Watts is volts times amps. So if you see more than 20 amps on your wattmeter, don't do that for much more than 20 min continuous. What I'm saying is your motor can take it briefly, or intermittently . But if you ride that thing full throttle very much, it WILL melt down a 500w rated motor.

When wanting to be precise in dealing with capacity of large battery, Ah are the better unit, since voltage is changing along the SoC curve.

Also deals better with Peukert's Law,

Both factors vary with chemistry, and where precision is not required it's a moot issue.

Obviously Wh are required when comparing between circuits at different voltages.

john61ct said:

When wanting to be precise in dealing with capacity of large battery, Ah are the better unit, since voltage is changing along the SoC curve.

Also deals better with Peukert's Law,

Both factors vary with chemistry, and where precision is not required it's a moot issue.

Obviously Wh are required when comparing between circuits at different voltages.

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On the other hand, if you look at what information each term provides, the the Ah capacity rating for a 20Ah battery only tells you that it could theoretically provide 20 amps of current for one hour, which in reality the battery may or may not be physically capable of, unless it can provide 20 amps of continuous current. The cells may or may not be capable. It doesn't tell you the energy stored (how far you can go), since that would vary with voltage (1v, 20 Ah = 20 watt-hours)

The watt-hour rating tells you the energy stored. Still doesn't tell you anything about the battery capability, but will tell you how far you can go with it.

I think the word "capacity" causes the most issues. There are at least a half dozen definitions with respect to electricity, and several even within the same industries, and they all mean something either slightly different, or completely different, but all very specific.