Recharging Monster Sized Batteries

[bikerjohn]

With my old ebike, the 36V/12Ah battery needed a recharge cycle after every commute, that isn't the situation with the CCX's 52V/19.2Ah battery. While I liked the idea of removing the smaller-lighter battery and recharging in an indoor environment, a 13pound monster battery pack seems happy with leaving it just where it needs to be ready for the next ride. I intend to do all recharging on the bike. With this new setup, I'll keep the charger on a count down timer and adjust the recharge time as needed to keep the battery in an optimal performance range.

My only concern is the extreme cold that the battery my encounter between use during the Winter. Right now It's 17°F outside, -about 37°F in the garage where the battery is on the bike. Overnight the outdoor temperature got down to 6°F (probably in the 20's in the garage). My intention is to perform a recharge cycle only when the ambient temperature is between 40°and 75°F

 

[MarkF]

I'm sure you've seen me post about batteries and temperatures. Anything below freezing can damage the electrolyte in your battery. Best to bring it in the house if it's going to be that cold.

 

[bikerjohn]

I'm sure you've seen me post about batteries and temperatures. Anything below freezing can damage the electrolyte in your battery. Best to bring it in the house if it's going to be that cold.

Understanding that an optimal temperature range for recharging a Li Ion battery (or any battery) is +45°F /-80°F , and that would enable garage recharging for the 10 months period of fair weather biking around here.
The essential questions then would be as follows:
Is it be safe to store a battery connected on a bike at a 35°F garage temperature?
Would it be safe storing the battery connected with an ambient garage temperature higher than 90°F ?

 

[MarkF]

I would not store my battery in the garage if temps were less than 45 F or above 85 F

 

[indianajo]

I would not store my battery in the garage if temps were less than 45 F or above 85 F

Why don't we all move to Maui. And since we are so rich, let's forget this whole commuting to work thing as a waste of time.
My garage gets down to about 25 F. My bike sits outside at the summer camp where it peaks at 100 deg F in the shade. I'm definitely not storing a device of the kind that incinerated a car on Rodeo drive or a Boeing airplane at the airport, in my house. I'll let you know in a year or two if life was affected.
I've only partially recharged the battery once since the first charge in October, and that was a nice day that was about 60 deg F.

 

[6zfshdb]

The best advice I can offer is to do what I did and check with your LBS or e-bike manufacturer. I was told emphatically by both, during cold weather, BRING THE BATTERY INDOORS!

 

[Mr. Coffee]

If you are worried about batteries catching fire inside your home, I'd consider a fireproof hoverboard bag (shoutout to @Court) for pointing them out to me.

 

[bikerjohn]

Significant considerations are a battery's awkward size and weight with regard to installing and uninstalling for recharging. Another concern is with the mechanical wear/stress over time from coupling and uncoupling the battery.

 

[ebikemom]

Whatever a person's bike storage circumstances it's possible to bring the battery inside if one lives in a cold place. This is something to take in mind when shopping for a bike--if you need to remove it for charging, how easy/hard is it to remove? I don't need to remove to charge, but I do swap batteries around between our bikes if I need one that is charged more than the one I'm using (and if the other person isn't needing their bike, so I can charge it more for them!)

 

[SirJonathan]

If you are worried about batteries catching fire inside your home, I'd consider a fireproof hoverboard bag (shoutout to @Court) for pointing them out to me.

Thanks for this! I've been reading about lipo battery bags but they're all too small for the gigantic 52V Juiced battery. This product looks like an excellent safety investment for storing your battery when you're on vacation or if you do charge unattended for some reason. $85 is a little steep but I guess it's slightly cheaper than a new house!

My only concern would be in the fire test I saw online those hoverboard batteries are quite a bit smaller than my eBike battery. The bag is large but that's to accommodate the large physical shape of the entire hoverboard while the actual battery pack is pretty small. If the 52V caught fire it would be much more dramatic and I wonder if the bag would still contain it.

 

[ebikemom]

Significant considerations are a battery's awkward size and weight with regard to installing and uninstalling for recharging. Another concern is with the mechanical wear/stress over time from coupling and uncoupling the battery.

Good points, and a good reason to meet a bike in person and try these processes prior to purchase, as well as to get a bike with a nice long warranty period.

 

[Ebiker01]

Thanks for this! I've been reading about lipo battery bags but they're all too small for the gigantic 52V Juiced battery. This product looks like an excellent safety investment for storing your battery when you're on vacation or if you do charge unattended for some reason. $85 is a little steep but I guess it's slightly cheaper than a new house!

My only concern would be in the fire test I saw online those hoverboard batteries are quite a bit smaller than my eBike battery. The bag is large but that's to accommodate the large physical shape of the entire hoverboard while the actual battery pack is pretty small. If the 52V caught fire it would be much more dramatic and I wonder if the bag would still contain it.

On that link at the bottom , there are several e bike battery specific bags/cases !

 

[MarkF]

I would like to point out that lipo bags don't really protect you like you think it should. If a battery catches fire, the bag will contain some of the fire but not all of it. The flames have to escape somewhere and there is always an opening in the bag for flames to escape. There has to be or the bag would turn into a bomb.
Batteries don't catch fire for no reason. They have to be damaged and a short present. When you damage your battery and cause a short, your going to know right away and not days later. If your battery has never been smacked in a crash, your probably going to be alright. If your still worried about it, a large plant pot, big enough for your battery to slip inside of, are a good way to keep the flames inside the pot so that can't go anywhere but up a little bit. When lithium catches fire it burns at almost 1000 deg F. There is no putting it out. You have to contain the fire and be ready for any collateral damage caused by the fire. Lithium burns hot and fast so they will burn themselves out pretty quick. Having a big enough pottery pot is good cheap insurance at keeping the fire contained inside the pot. There will be a little smoke damage but that's it. Ceramic pots can handle the extreme heat and are a great way to keep your battery contained and your house protected.
Our battery packs that come from bike company's are built very well and don't just catch fire for no reason. I have no problem in bringing my pack into my house to keep it out of the extreme hot and cold. If I get into a bad crash with my bike and the battery case is damaged, I would dispose of my battery and get a new one. No sense in taking chances with a damaged pack.

 

[Mr. Coffee]

Thanks for this! I've been reading about lipo battery bags but they're all too small for the gigantic 52V Juiced battery. This product looks like an excellent safety investment for storing your battery when you're on vacation or if you do charge unattended for some reason. $85 is a little steep but I guess it's slightly cheaper than a new house!

My only concern would be in the fire test I saw online those hoverboard batteries are quite a bit smaller than my eBike battery. The bag is large but that's to accommodate the large physical shape of the entire hoverboard while the actual battery pack is pretty small. If the 52V caught fire it would be much more dramatic and I wonder if the bag would still contain it.

Well, strictly speaking lithium battery "fires" are a thermal runaway reaction where the cells get really hot, hot enough to cause nearby things (or the plastic casing of the battery) to catch fire. I figure if the bag is tightly closed there will be little oxygen in the bag so any fire can't really last long. I always store my batteries either on the bike or in a bag like that and someplace away from anything even vaguely flammable. My home has stone floors and concrete countertops so there are plenty of safe places to leave the bagged battery.

 

[MarkF]

Lithium doesn't need very much oxygen to burn and there is no way to put it out once it catches fire. The smartest thing you can do is be smarter than the battery. Always place your battery in an area where if were to catch on fire, it can't catch anything else on fire. Lipo bags are a false sense of security but as long as you set it down on something that can't catch fire, like Mr Coffee does, you should be fine. A large enough flower pot is just a better containment devise if something were to happen. I would never trust a lipo bag to contain a lipo fire.

 

[Captain Walnut]

With my old ebike, the 36V/12Ah battery needed a recharge cycle after every commute, that isn't the situation with the CCX's 52V/19.2Ah battery. While I liked the idea of removing the smaller-lighter battery and recharging in an indoor environment, a 13pound monster battery pack seems happy with leaving it just where it needs to be ready for the next ride. I intend to do all recharging on the bike. With this new setup, I'll keep the charger on a count down timer and adjust the recharge time as needed to keep the battery in an optimal performance range.

My only concern is the extreme cold that the battery my encounter between use during the Winter. Right now It's 17°F outside, -about 37°F in the garage where the battery is on the bike. Overnight the outdoor temperature got down to 6°F (probably in the 20's in the garage). My intention is to perform a recharge cycle only when the ambient temperature is between 40°and 75°F

I'm wondering about topping off my CCX battery after my commute, and am wondering what you've settled on. I'm using a little over a third each way, so today I charged at work. But I'm wondering if I should not charge tonight and let the battery get down closer to 20% on the ride in tomorrow. I know best practice suggests keeping it between 20-80 percent, and I know folks here are somewhat fanatical about not charging to full (my LeBS disagrees), but how important is it to discharge down to the lower end of the battery before recharging?

 

[harryS]

Captain Walnut, I believe it's better to recharge at 50% than try to hit the 20% low point. The fewer electrons stripped out of their happy homes in that lithium soup, the fewer that have to find their way back.

 

[bikerjohn]

I'm wondering about topping off my CCX battery after my commute, and am wondering what you've settled on. I'm using a little over a third each way, so today I charged at work. But I'm wondering if I should not charge tonight and let the battery get down closer to 20% on the ride in tomorrow. I know best practice suggests keeping it between 20-80 percent, and I know folks here are somewhat fanatical about not charging to full (my LeBS disagrees), but how important is it to discharge down to the lower end of the battery before recharging?

IF there is no need to discharge the battery below a 50%, THEN don't! And don't store a lithium Ion battery fully charged for any significant period of time! Your write-up about topping-off at work sounds good.

Consider that the CCX's battery charger has a high voltage cut-off limit below 100% of the maximum capacity of the 52 volt battery. The charger seems to stop the recharge at 57.6 volts (about 4.11 volts per cell -about 90% full). That should be good enough!
After a typical work commute, my battery has a left over capacity of about 66%, I don't immediately recharge at that point (with having enough capacity for another commute). Generally though, just before the next ride I will top off the battery with a recharge cycle.

An important aspect for extending battery life is understanding it is better not to store a battery in a fully charged or discharged state . The highest capacity my battery ever reaches is 90% full -and that only occurs just before I start a ride. Additionally I've set the low voltage cut-off at 45 Volts. That low limit can be adjusted on the matrix display on the bike.

 

[bikerjohn]

Captain Walnut, I believe it's better to recharge at 50% than try to hit the 20% low point. The fewer electrons stripped out of their happy homes in that lithium soup, the fewer that have to find their way back.

Yup, sounds like a good tactic! No need to stress the battery. Experts say NOT to store a lithium Ion battery in a fully charged state (or a voltage below 50%) any longer than necessary. Top-off the battery just before it's next use.

 

[BBassett]

IF there is no need to discharge the battery below a 50%, THEN don't! And don't store a lithium Ion battery fully charged for any significant period of time! Your write-up about topping-off at work sounds good.

Consider that the CCX's battery charger has a high voltage cut-off limit below 100% of the maximum capacity of the 52 volt battery. The charger seems to stop the recharge at 57.6 volts (about 4.11 volts per cell -about 90% full). That should be good enough!
After a typical work commute, my battery has a left over capacity of about 66%, I don't immediately recharge at that point (with having enough capacity for another commute). Generally though, just before the next ride I will top off the battery with a recharge cycle.

An important aspect for extending battery life is understanding it is better not to store a battery in a fully charged or discharged state . The highest capacity my battery ever reaches is 90% full -and that only occurs just before I start a ride. Additionally I've set the low voltage cut-off at 45 Volts. That low limit can be adjusted on the matrix display on the bike.

What I have done with my EM3 52V 30Ah packs is to fully charge them (58.8V) upon receiving them and then every 50 to 60 recharges. I have used a Grin Satiator charging to 55.4V (80%) and never discharging past 45.4V (20%) not using more than 60% of the packs capacity for the majority of all recharges. I also use a 300W folding solar panel that charges to 56.8V (approx 87% charge). Using no more than 60% of the batteries capacity can extend the life of the battery significantly, to the tune of almost triple the number of recharges. But fully charging and over depleting aren't the only aspects to think of when trying to baby your batteries for extended life. What concerned me most was how quickly I could charge the packs without stressing them. That's the real inconvenience of big batteries for me... the extended charge times. So I asked EM3's technical guru Joseph the following question:

Q - "I use a pair of EM3 triangle packs (30+Ah) and charge using a Grin Satiator. I take it easy on the packs when charging nightly but would like to know if fast-charging a partially depleted pack for under 2 hours is bad for them. Say... for a lunch stop, 90 mins. charge at 8A. If it doesn't push the packs past 80 to 85% (55.4 to 56.3 V) does fast charging stress the battery?"

A - "Those batteries are so large in terms of capacity that the charge rate, even at 8A is low for the cells. 8A for a 28Ah battery is still less than 0.3C – which is lower than the recommended charge for long-life. You won’t have any issues charging either battery at 8A. Those are very large batteries relative to the charge rate and certainly wouldn’t be considered fast charging. Typically the max recommended charge rate for a lot of the cells is 1C – that would be 28A for the smaller of the 2 batteries – however, there are other limiting factors such as the BMS etc. to take into consideration. Suffice to say charging below 0.3C is far removed from fast charging and there won’t be any issues. Joseph"
"

Using only 60% of the packs total capacity (80% charge down to 20% charge- 55.4V to 45.4V) to extend their life is also why you want to use the largest possible battery your bike can carry if range is your primary focus. The only downsides to a large pack is initial cost and weight. The benefits of being able to charge as quickly as possible without stressing the packs and getting ranges of 80+ miles on 60% capacity warrant both the weight and the upfront cost.