Voltage chart for 52v

[thomasroine]

I would like to have a chart/table for a 52v battery that shows "% left" like the one below. Anyone knows where to find that?

https://cdn1.bigcommerce.com/server800/9vkjq73s/product_images/uploaded_images/48v-nominal.jpg?t=1467500767

[Kocho]

Here. Comes from the same place. This has been posted here a few times. Search the forum for "power curve for a 52v" batery for example.

[Rodney64]

Note: This is an estimate for all 52 volt batteries. GA cells 45 volts is 10% remaining.

[Dynamix]

Yup looks right by how my 52v 19.2ah battery is

[skymon]

Here's another:

https://electricbike.com/forum/filedata/fetch?id=30166&d=1489464332

Can't tell you which is more accurate.

[Rodney64]

It depends on what cell you are asking about.

[Kocho]

Which one is for the GA cells?

[Rodney64]

neither, I would need to put it into a graph which I can do.

[Kocho]

That would be great!

[thomasroine]

Rodney64, could you do it for a 52v GA?
I have this battery:
52v Panasonic Shark Pack 13.5ah GA

[jjs]

All,

Looking for feedback on this. I've been trying to model a Voltage/Amperage/Watt Hours/Miles chart and I got a little bit carried away!

Disclaimers:

• I'm not familiar with electrical engineering; I backed into these numbers.
• I know that, particularly at the extremes, Voltage and Amperage changes are not linear.
• The model doesn't account for degradation over battery cycles.
• I've hidden some of the rows to reduce image size.
• Panasonic GA discharge charts are from batterybro; hopefully that's ok.
• I know this is a lot of questions in one post; I don't expect answers to any/all of them, but I thought this might be useful for discussion.

Some questions:

1. How does one read the batterybro discharge chart? Specifically, what is each set of curves?
2. If the GA cells are rated at 10A max discharge, and I have a 7p pack, then it is capable of 70A discharge?, so if I'm running nearly 30A up the 360 foot Dolores Heights/Liberty Hill in San Francisco hill to my house, I am not stressing the pack? As an aside, I'd prefer that the Bafang/Luna Cycle DPC-18 display had really big numbers for the speed and amperage/wattage in lieu of the speedometer graphic. It's huge screen and most of the space is wasted. I've ordered an egg rider V2.
3. Is my logic correct that *all* of total watt hours of a battery pack are not usable due to the Low Voltage Cutoff of the BMS or Controller? In the model below, 327 watt hours remain at LVC.
4. Which is more likely to cut off first; the LVC of the BMS or the controller?
5. Do you agree that the "usable" capability of the pack, at medium efficiency is between 61 miles (Charge to 100%, run to LVC) and 36 miles (Charge to 80%, run to 20%)?
6. What lower end does the voltage meter on my Bafang/Luna Cycle DPC-18 use to calculate percentage? If that lower end is zero, then *percentage* on the meter is not really useful as a pack with, for example, 20% voltage may have reached the low voltage cutoff?
7. I was thinking about an industry standard test condition for e-bikes, similar to the mpg test conditions used for cars. Thoughts?

Images from https://cdn.shopify.com/s/files/1/06...79572025043155

[Sting]

I have always been confused on the percent of charge. My Pedego 48v pack at 100% is 58.8 volts. So what voltage is 80%? I would also like to know the proper level for long-term winter storage? Thank you.

[Tommycat]

Hi Sting,
And welcome to the forum!

You'd better double check those numbers! ;-) perhaps these will help.







For winter storage I'd probably stay close to 50%, checking it every few weeks.


Regards,
T.C.