Charging to 80% without a Satiator

[Justin Fischer]

Greetings all, I just did some math to figure out how to charge my battery to 80% based on timing the charge cycle on the basic 2 amp charger. Here's what I came up with:

The 52V, 19.2AH battery is actually listed as 52V, 19.2AH on the label, so that's good, I'm not sure where the 52V, 21AH battery listed on the Juiced website comes for battery life comes from. But based on Juiced's documentation that they are LG batteries, 14 series (52V) by 9 parallel, that gives them a nominal capacity of either 19 or 20AH based on LG's HE4 or MJ1, the closest available on https://www.ebikes.ca/tools/charge-simulator.html?bat=cust_c27_s14_p6_l30 Using ebike.ca's calculator, based on 56.3V = 80% = 16.35AH, here's a quick chart of battery voltages, levels, and percentages for the 52V battery available on the CCS and RipCurrent. I based this on them being MJ1 cells. If anyone knows for sure, please chime in.

48.7V - 20% - 4.08AH
49.3V - 25% - 5.10AH
49.8V - 30% - 6.12AH
50.4V - 35% - 7.14AH
51.0V - 40% - 8.17AH
51.4V - 45% - 9.19AH
52.1V - 50% - 10.21AH
52.8V - 55% - 11.24AH
53.5V - 60% - 12.26AH
54.2V - 65% - 13.28AH
54.9V - 70% - 14.31AH
55.4V - 75% - 15.33AH
56.3V - 80% - 16.35AH

Be aware, the CCS low voltage cutoff won't go higher than 43V (at least on mine). Feel free to correct me on my math if I messed anything up, and all values are rounded, including to a single place for voltage because that's what the onboard display will indicate.

To demonstrate, if you were at 20%, 4.08AH, and you wanted to get to 80%, 16.35AH, 16.35-4.08 = 12.27AH differences, at a charge rate of 2AH, gives you 6.135 hours, 6 hours and 8 minutes.

This is all a rough approximation, but if you haven't gotten a satiator yet, I hope this helps you estimate charge time to 80%.

 

[jazz]

Great write up. Should help many people out. Personally, I only charge below 100% when I am storing it for long periods such as over the winter and charge it to around 60% or so. Otherwise, I charge it up full to 100% and use it.

My thought on it is this - yes, it may shorten the overall longevity of the battery. However, if I am not using up to 40% of the battery (using the 20-80% rule), then what is the point really? If it lasts me 3-4 years of good use (which mine typically do), the battery technology by then will likely be slightly different, cheaper and longer lasting anyway.

Every use case is different. Just my 2 cents.

 

[Justin Fischer]

I use 55% of my charge with both legs of my commute combined, so for my use case it's very useful to be able to stop charging at 80%, get back home at 25%, and repeat, letting me get those extra cycles essentially for free. I agree, a lot of people will want to top theirs off for the extra speed given by operating at a higher voltage, the ease of charging, and extra range, but I'm commuting every day (ideally), so I'd like to have the extra battery cycles.

 

[jazz]

Makes perfect sense for your use case

 

[Bruce Arnold]

I'm not sure where the 52V, 21AH battery listed on the Juiced website comes for battery life comes from.

They used to sell a 52V, 21Ah battery when the RipCurrent first came out. So that's where that stat comes from.

For that matter, I have a 48V, 17.4Ah battery. I got one of the last ones sold. The stats used to reference that one, but they did update the graphic a few months ago.

 

[bikerjohn]

Greetings all, I just did some math to figure out how to charge my battery to 80% based on timing the charge cycle on the basic 2 amp charger. Here's what I came up with:

The 52V, 19.2AH battery is actually listed as 52V, 19.2AH on the label, so that's good, I'm not sure where the 52V, 21AH battery listed on the Juiced website comes for battery life comes from. But based on Juiced's documentation that they are LG batteries, 14 series (52V) by 9 parallel, that gives them a nominal capacity of either 19 or 20AH based on LG's HE4 or MJ1, the closest available on https://www.ebikes.ca/tools/charge-simulator.html?bat=cust_c27_s14_p6_l30 Using ebike.ca's calculator, based on 56.3V = 80% = 16.35AH, here's a quick chart of battery voltages, levels, and percentages for the 52V battery available on the CCS and RipCurrent. I based this on them being MJ1 cells. If anyone knows for sure, please chime in.

48.7V - 20% - 4.08AH
49.3V - 25% - 5.10AH
49.8V - 30% - 6.12AH
50.4V - 35% - 7.14AH
51.0V - 40% - 8.17AH
51.4V - 45% - 9.19AH
52.1V - 50% - 10.21AH
52.8V - 55% - 11.24AH
53.5V - 60% - 12.26AH
54.2V - 65% - 13.28AH
54.9V - 70% - 14.31AH
55.4V - 75% - 15.33AH
56.3V - 80% - 16.35AH

Be aware, the CCS low voltage cutoff won't go higher than 43V (at least on mine). Feel free to correct me on my math if I messed anything up, and all values are rounded, including to a single place for voltage because that's what the onboard display will indicate.

To demonstrate, if you were at 20%, 4.08AH, and you wanted to get to 80%, 16.35AH, 16.35-4.08 = 12.27AH differences, at a charge rate of 2AH, gives you 6.135 hours, 6 hours and 8 minutes.

This is all a rough approximation, but if you haven't gotten a satiator yet, I hope this helps you estimate charge time to 80%.

Justin, I'm confused a bit.
The voltage/percentage capacities you state above vary significantly from from the graph I re-posted yesterday:

I'd like your input to clear up the discrepancies.
For instance the graph I posted shows 56.3 volts as an 85% charge on a 52 volt 14s pack (-vs-80% on the list above) . Which is correct?
The graph also indicates a 20% state of capacity is 45.4 volts -this also varies significantly from your listing of 48.7 volts.
Also, when calculating 20% of 19.2 Ah I come to the value of 3.84 Ah (not 4.08 Ah). Perhaps you have a better understanding of the discrepancies?
While trying to get an accurate grasp on optimal battery usage inaccurate charts, graphs, or statistics only confound the confusion already existing on the subject.

 

[Justin Fischer]

Who originated the chart? No single resource is going to be perfect, and the charts here show why: https://lygte-info.dk/review/batteries2012/Common18650CurvesHigh UK.html

Batteries with the same rated capacity have different actual mAh depending on how much load you put them under, with the discrepancies becoming more noticeable the more power is pulled from each cell. That's why the calculator for the Satiator that I used asked what cell was in the pack, and I made my best guess based on capacity - the MJ1. Until someone rips open the pack and tests an individual cell, this is the variable which will change capacity.

 

[Bruce Arnold]

The graph @bikerjohn posted doesn't reference mah at all, and isn't relevant to capacity. It would be equally accurate (or not) whether your battery has 4 or 40 mah.

Is the chart accurate? Experience of a lot of us suggests that yes it is, within a couple tenths anyway.

Bikerjohn, if you're trying to figure out how to time your charge to get to 80%, it's fairly simple. With the battery on the bike, or not if you use a multimeter, take note of the beginning voltage and time. Charge the bike until you get to ~55.4 V. Note the time again. Simple math will give you the time it took to go from X volts to 55.4. Extrapolate to get an approximate time from any other starting voltage. If you miscalculate a bit and end up anywhere between, say, 75% to 85%, you've done no harm and your range won't be affected. (If you're taking a really long ride, charge to 100% anyway.)

 

[MarkF]

Look at the 1s cell voltage versus the capacity %. Multiply your cell count to get your voltage level.

 

[MarkF]

Based on the chart above. A 13s battery, or 48 volt as there labeled, would be 20% 48.9 volts and 80% 52.26 volts. Capacity doesn't matter. Only cell voltage. Now these numbers will change a little as a battery is used and aged but not much.

Bikerjohn
Your graph is the wrong one. Not your fault.

The graph i just posted comes from a lipo manufacturer and not an ebike shop.

 

[Feliz]

All my bikes have either battery volts or percent shown on the display which makes it easy. Of course that means charging it on the bike which I do anyway. Whether they are accurate is another thing.

 

[bikerjohn]

View attachment 28517Look at the 1s cell voltage versus the capacity %. Multiply your cell count to get your voltage level.

There is a very significant discrepancy between the charts at 20% !
Based on your formula for using the chart above, a 14s battery, like the CCX 52V battery, has a 20% voltage of 52.22 volts. How are you able to verify the charts accuracy? Where can I find a link with a write-up on the calculations related to this chart?

 

[MarkF]

It took me a while to figure out what they did wrong What's wrong with that chart is they are using 3 volts as 100 % discharge. Lipos are discharged long before that. So there basing there math on 3 volts to 4.2 That chart might be outdated too.

I own a lipo battery business and work with the engineers that make the lipos I sell. They agree with the chart I posted and that works for me. Sorry i don't have any write ups to point to.

 

[Bruce Arnold]

Based on the chart above. A 13s battery, or 48 volt as there labeled, would be 20% 48.9 volts and 80% 52.26 volts. Capacity doesn't matter. Only cell voltage. Now these numbers will change a little as a battery is used and aged but not much.

Bikerjohn
Your graph is the wrong one. Not your fault.

The graph i just posted comes from a lipo manufacturer and not an ebike shop.

LiPo is different chemistry. The chart Bikerjohn posted is correct, within the usual variance.

@Thomas Jaszewski, do you have any input? You know a whole lot more about this than I do.

 

[MarkF]

Lipo is not a different chemistry. What do you think is in your bike pack?
You can believe what you want, but that chart is very wrong.

 

[2wheeler]

You guys are confusing the hell out of a lot of us that rely on others knowledge/advice. Shouldn't Juices V chart from their website be used to be accurate? All input is welcome but please be accurate. These 19ah 52v batteries are expensive to replace.

 

[MarkF]

The chart I posted is an updated chart. I am the North American distributor of the battery I sell. https://www.dinogylipos.com/
I sell to top racers in the country and have to know what i'm talking about. I get my information from a lipo factory and the engineers that work there. Not an ebike shop.
The chart from Juice is wrong. Sorry to be confusing. My goal when I come on here is to help educate you guys.

 

[surfstar]

I made a chart for my battery - 12.8 Ah 48v that comes with the CCS.
% / V and time to charge based on the 2 amp stock charger (add time if truly topping off battery) - just to give myself something to quickly reference when setting a timer on the charger. I taped this to my charger.

Not sure if it is 100% accurate, but I based it off of info found on the forums and Juiced site (42v cutoff for 20% IIRC)

 

[MarkF]

Your numbers are off a little. Take the chart I posted and use the voltage numbers in the 1 cell column. Multiply by 13 to get your percentage. 20% charged would be 3.73x13 =- 48.49 Do not go below this number if you want your batteries to last longer.
80% full would be 4.02 X 13 =52.26 You can go as high as 4.10 and still get better cycles compared to 4.20
I have been teaching my customers how to take care of their batteries for 7 years now. I recently got into ebikes and can't stand by when I see bad information being posted. The juice chart posted is close on the top end but goes horribly wrong down on the bottom.

 

[bikerjohn]

The chart I posted is an updated chart. I am the North American distributor of the battery I sell. https://www.dinogylipos.com/
I sell to top racers in the country and have to know what i'm talking about. I get my information from a lipo factory and the engineers that work there. Not an ebike shop.
The chart from Juice is wrong. Sorry to be confusing. My goal when I come on here is to help educate you guys.

Mark, I'm curious to learn more!
Do you sell a battery pack with a voltage configuration that can power an ebike? I did not see any 13s or 14s battery configurations on your web site. I'll be the first to admit I don't fully understand the significance of (s)tack numbers, except that a greater number equates to more cells in series and a higher voltage battery. Would the 1s thru 10s batteries I see on your website be useful to power an ebike? I would like to see a mathematical formula used in arriving at the voltages listed in the chart you've been blogging.