Parking my bike in the sun all day, what to do?

slickenned

100 µW
Joined
Apr 27, 2017
Messages
9
Hi endless-sphere forums

TL;DR (too long;didnt read) below

I just recently bought a Motorino XMB scooter to go to and from work during the summer and for fun. It uses 6 12v 20A SLA's in series (72v total). I didn't do my due diligence by reading this forum before my purchase, and among other things I am worried about the SLA batteries while I'm at work.

I will be parking my bike outside of my work and it will be subjected to the full force of the sun (ill probably cover it up with a motorcycle cover) during the summer. I also wont have access to a outlet outside. I was originally going to just park and it and leave it, but the SLA batteries apparently will lose overall lifetime charge fast in these conditions because of the lack of charging for 8-10 hours a day and of course the temperatures it'd be subjected to.

So I was thinking of upgrading to good ol' Lithium batteries, and I think that will solve the charging problem, but not the temperature problem. Hence, I guess the batteries need to be easily removable. Or do you guys think I should really worry?

I was also considering how I can make the batteries removable so I can at least store them inside. I've seen the 'silver fish' metal cased batteries for Ebikes and was thinking maybe those can fit in the battery box in my XMB scooter. I've emailed Pingbattery to ask if they'd do a custom battery for that, or at least a custom battery that I could then fit into one of those casings. Is there somewhere else anyone would recommend for a custom battery build like that?
Or maybe the silverfish batteries are a bad idea (if they'll even fit) and I should look at some kind of rack and easily removal battery leads? I have no idea what'd Id be looking for though.

TL;DR:

My scooter (motorino XMB, 72v 20A bike, 6 12v SLA batteries) needs to be subjected to the sun and summer weather conditions all day, what should I do to keep the batteries from frying? I have the ability to store them indoors, but in their current stock configuration, they are very user unfriendly to remove and reconnect every day. I am very willing to buy new batteries, very novice skill level for modding and electricity (but wanting to learn more and try).

I cant imagine this scenario is completely new to this forum, but I don't know what to search to find other people's solutions.

Thank you for reading! My first post on this forum, I've got the tingles :D .
 
I never heard of SLA having that much issue with heat, at least compared to lithium. I'd confirm that before worrying about it, probably starting with google and/or 'battery university'.
What level will the lead acid be sitting at while at work? I'm thinking if you plan to do round trip that should be at least half capacity, and likely more since lead acid has to compensate for more inherent voltage sag. No specific firsthand exp here, but I'm thinking setting @ 12v or so for 1/3 - 1/4 of the day won't be hugely destructive to them. Even lower probably isn't all that bad.

Yes, lithium would actually be happy sitting at 1/2 SOC, but apparently heat is more degrading to the chemistry. I think I'd run the SLA for now or even thru their lifetime, and plan on replacing someday with the removable LI pack like you mentioned. It really is ridiculous the amount of capacity they have VS Lead. Lithium does make more sense for alot of mobile applications.
 
How far is a one way trip ?
How hot does the surface of the battery compartment get?
My summer temps are 110 f in the late afternoon.
I find any patch of shade to hide my bike and battery pack in.
Shady side of the building ,dumpster ,No trees available for me.
I use Nissan leaf cells 3 yrs old. I get an easy ten miles of hard acceleration .
35 mph cruise and great hill climbing ( the hills here are insane ) . Per day including solar exposure.
Any part facing the setting sun the is too hot to touch. Especially the dark seat .

In a neighboring town they hold an annual solar egg cooking contest .
 
Excessive heat is bad for all types of batteries. Lead-acid will be likely to die from other causes before the heat related things would happen. For sure lithium hates high storage temps.

Some kind of shade, like a motorcycle cover or anything to keep the direct sun off the battery compartment will help a lot.
 
Lead batteries don't like heat and like to be at full charge 13.5volt each 12v battery at all times. Those are the trickle sla charger for vintage cars, motor homes ect. So charge ,charge and keep charge if to hot to the hand. Do good up that steep a hill or dont charge if hot when charging unplug charger. When battety is dead ask. Here for new updated advise. Like a leaf modules for a vattery or what if ? Good luck. Lock it good.
 
I agree with most of what has already been said, but hey, you have the batteries now, they have no resale or trade-in value, so just use them as long as they work. Maybe there will be some great new chemistry available by then, who knows.

Some of our cars sit out in the sun all day and I'm sure it gets pretty hot under the hood, plus when the car is running the battery is right there by the hot engine and most car batteries last for 5 to 10 years.

It would help to know how far you have to ride, where you are, a link to the bike, etc. in order to get any good advice.

Good luck with your bike.
 
I wouldn't worry about the heat. What I would worry about is leaving them in a discharged state. That's what's going to kill them. Not the heat. I'd replace them with 10ah of 20s rc lipo if I wanted the same range as you get with the sla battery pack. That would be under 10 lbs. and only take up about 1/6 the space.
 
Ditto on ignoring the heat (unless maybe it's like summer here in phoenix az, where it can get 150f+ inside a car or other enclosed space).

but leaving them in discharged state is going to be bad for sla.

if there's only one thing you can do differently, it's to charge it as soon as you reach your destination.



for the heat, whenever i've had to park in the sun a lot, i've considered insulating the battery box with thick styrofoam, with reflective material on the outside, so that it takes a lot longer for heat to penetrate it. closest i have come to actually implementing this recently is to build a wooden box under the seat of my trike to hold batteries, cargo, etc., and insulate that.
 
I'm gonna assume that the large black box under the "fuel tank" is actually the battery (would need to be to maintain a low centre of gravity)

xmb-gre-a.jpg


It would be trivial to make a box that fit in the same space, but was a few centimeters smaller on each side, so that it was easy to remove after each ride.

But like everyone else has said, use up the lead until they no longer perform. Just be ready to cut over quickly, as lead can fail pretty quickly once it starts going down hill.
 
sorry everyone for not replying sooner. still getting used to where the forum tools are and such.

one trip to work one way is about 8km. so 8km, battery sits for 8 hrs, them 8km back. i cant charge the battery during the day. by the time im back home, the voltmeter when under load reads half charge.

the place i park it at is a plaza that has no trees of any size big enough for shade. i could park it in front of a large big box store, the store front faces north so itd be in shade. but id be a little worried about idoits messing with it since it stands out a bit and a small amount of foot and a larger amount of car traffic. anyone have big issues with this? its not a bad neighborhood or anything, and id cover it with a cover.

im in the greater toronto area. right now the weather is rainy and all over the place for temperatures, running from 4 celcius to 17 or more (a few times in the last few weeks). sorry im typing this from my phone so i dont know those temps in freedom units off the top of my head :D .i havent rode it to work for the last little while due to the weather variability.

Yes the black box is the battery box. should i make a battery box out of wood? plastic? all of the battery box builds ive seen on here are for ebikes and not scooters..

To review this bike i have to say:
I have no experience with scooters either than this one. That being said: Awesome bike. Satisfying acceleration, good on hills even for my lardo body (250lbs), lights are SUPER BRIGHT, has 6 lead acid batteries standard that make the bike heavy as hell to move unfortunately. Seat is pretty comfortable after getting used to it for a day. The metal frame is welded well and just overall the bike feels like quality from any angle. longevity wise i have no idea how good it is. People ask me if this thing is electric or not, even though the plate on the back says electric. It is very unique on the road vs all the other plastic scooters youll see out there.

I can get to 50km easily on this thing. going full tilt going flat terrain/slightly downhill can get to 60km or more. I REALLY wish i could get this licensed as a mophed, but i cant find the vin on this thing and ive heard if it does have a vin it doesnt have enough digits to license it or something. Im probably missing something.

Things I wish were improved would be to add lights to the dash as you cant see them in the dark.

I wish the 'gas tank' in the middle could have doubled as storage for a cell phone or wallet. it looks really cool but its a waste of space.

I wish the plastic framing below the battery storage (the black box in the center of the bike) was not open at the front. it collects dirt over time and will probably be a rust point for the screws that hold it together.

one more gripe: i wish the wireless key lock wasnt so loud. its obnoxiously loud. so bad i put duct tape over the speaker and poked a single hold to half the volume of it. itd be nice if the lights flashed instead. I understand why the speaker is loud, but it should only be that loud when the bike is getting stolen.

These are all very minor gripes as I am going to hold onto this bike for a long time and be super happy with it. Its also very easy to modify and tweak this bike. theres a small white wire connector under the seat that disconnects really easily.
 
by the way that review is also what i posted on the motorino website, in case you look and think why it looks so similar.
 
Those temps aren't anywhere near the danger zone for LiPo let alone lead. Even in the black box in direct sunlight (usually +10 to +15* depending on ventilation) you're only just at the start of danger zone. Around 35* you start getting accelerated decomposition in fully charged LiPo. Nothing in lead.

And if you're doing 16km out of a 50km range, sulfation will only be a mild issue. The danger zone is below 50% state of charge. Just remember to charge every night because a second day will push you to 32km, over the half way mark.

Hey, you know that once you go lipo, you can get the same range for about 4.5kg? (10 lbs). You only need 10ah due to lack of Peukerts effect, and being able to use the whole capacity without shortening the life of the battery. I'd be thinking custom controller once the warranty ran out. 500w? Pfft. That rear hub looks like it could do 2-3kw...

Box can be whatever material that you're comfortable working with. People have done everything from MDF to perspex to abs to coreflute and a few other weird materials. Some people have even used converted ammo boxes! As long as you can drill it to let the cables out, and you can restrain it inside the frame, anything goes. (Don't forget to insulate if you use metal. Don't rely on paint to stop short circuits etc.)
 
Sunder said:
Those temps aren't anywhere near the danger zone for LiPo let alone lead. Even in the black box in direct sunlight (usually +10 to +15* depending on ventilation) you're only just at the start of danger zone. Around 35* you start getting accelerated decomposition in fully charged LiPo. Nothing in lead.

And if you're doing 16km out of a 50km range, sulfation will only be a mild issue. The danger zone is below 50% state of charge. Just remember to charge every night because a second day will push you to 32km, over the half way mark.

Hey, you know that once you go lipo, you can get the same range for about 4.5kg? (10 lbs). You only need 10ah due to lack of Peukerts effect, and being able to use the whole capacity without shortening the life of the battery. I'd be thinking custom controller once the warranty ran out. 500w? Pfft. That rear hub looks like it could do 2-3kw...

Box can be whatever material that you're comfortable working with. People have done everything from MDF to perspex to abs to coreflute and a few other weird materials. Some people have even used converted ammo boxes! As long as you can drill it to let the cables out, and you can restrain it inside the frame, anything goes. (Don't forget to insulate if you use metal. Don't rely on paint to stop short circuits etc.)

I was wondering how may lithium batts i need to get a near equivalent amount of range to what i have now. theyre damn expenaive, and the range i get on 6 sla's id be happy to get if i converted to lithium. 6 li batteries would be pricy. Granted, id want the same zip i have now. 72 volts is super fun :D

Old ammo boxes would be super cool and go with the bike's motif really well. im gonna check that out for sure :D
 
slickenned said:
I was wondering how may lithium batts i need to get a near equivalent amount of range to what i have now. theyre damn expenaive, and the range i get on 6 sla's id be happy to get if i converted to lithium.

While almost all lead is 12v, hence why you need 6 of them, Lithium can be many different voltages.

72v in lead = 6 x 13.8 (high) = 82.8v
72v in lead - 6 x 11 (low) = 66v

You can replicate something close to that in a few different ways:

18 cells in series (3 x 6S will be cheapest): https://hobbyking.com/en_us/multistar-high-capacity-6s-10000mah-multi-rotor-lipo-pack.html
18 x 4.2v = 75.6 - Will work well on the bike, but you will need a new charger. The lead acid charger will overcharge the cells.
18 x 3.5v = 63v You will get about 90% of the rated capacity, but it will be safe. In fact, it's a good battery longevity strategy

20 cells in series (5 x 4S will be cheapest) https://hobbyking.com/en_us/multistar-high-capacity-4s-10000mah-multi-rotor-lipo-pack.html
20 x 4.2v = 84v - Old charger will be fine, and in fact will mildly under charge it, which is another good battery longevity strategy
20 x 3.5v = 70v - This is a bit iffy. It's not yet in damage range of the batteries, but its less than ideal for RC Lipo. It will be safe for many 18650s, that discharge to 2.7v instead of 3.5v.
 
Do you have lipo battery experience ? They are the most volatile of the batteries. Even people with years of experience have lipo rc fires. Lot of safer batteries out there. Plus a special charger and power supply a bms ect. Not simple.
 
There are other battery opinions like 18650 or used leaf modules from cars. I would use a bms for a plug and play. Rc lipo don't have good quality control compared the a Samsung or panasonic cell of quality. They also make batteries for flashlights.
 
I've got years of experience with rc lipo and have never had a fire. And I would never use 18650's.
 
Sunder said:
slickenned said:
I was wondering how may lithium batts i need to get a near equivalent amount of range to what i have now. theyre damn expenaive, and the range i get on 6 sla's id be happy to get if i converted to lithium.

While almost all lead is 12v, hence why you need 6 of them, Lithium can be many different voltages.

72v in lead = 6 x 13.8 (high) = 82.8v
72v in lead - 6 x 11 (low) = 66v

You can replicate something close to that in a few different ways:

18 cells in series (3 x 6S will be cheapest): https://hobbyking.com/en_us/multistar-high-capacity-6s-10000mah-multi-rotor-lipo-pack.html
18 x 4.2v = 75.6 - Will work well on the bike, but you will need a new charger. The lead acid charger will overcharge the cells.
18 x 3.5v = 63v You will get about 90% of the rated capacity, but it will be safe. In fact, it's a good battery longevity strategy

20 cells in series (5 x 4S will be cheapest) https://hobbyking.com/en_us/multistar-high-capacity-4s-10000mah-multi-rotor-lipo-pack.html
20 x 4.2v = 84v - Old charger will be fine, and in fact will mildly under charge it, which is another good battery longevity strategy
20 x 3.5v = 70v - This is a bit iffy. It's not yet in damage range of the batteries, but its less than ideal for RC Lipo. It will be safe for many 18650s, that discharge to 2.7v instead of 3.5v.

Woah! thats cheap and small. damn thats awesome. thats really awesome. i was wondering why Lipo was a thing if LiFeSO4 was better but yeah, thats like 500 bucks vs 1200+. easier to manage too since its smaller bits. And so much lighter! ill probably do the 5x4S for simplicity. my charger is a 72v 3A charger.

so i can fashion some type of box to put this in, then maybe remove it when i want to charge it and put it in something fire resistant when charging. connect them in series and charge with the old charger sounds great. do i need to worry about over charging or balancing? this will be plugged in all night ideally. or do these packs you linked have a bms? i dont know what im looking for on the product page.

ill look at lipo pages for warning and stuff, but any quick notes i should be concerned about? or is there a post on this forum for the ins and outs of lipo you can link me to? you guys are awesome, everyone who has sent replies. thank you so very much for your insight and for putting up with my verboseness :D

if this all works out ill post some photos. wont be anything super fancy but might help someone else doing something similar
 
Please read and understand what you need to start. You connectors, wire, shrink tube. A power supply for the rc balance charger or a bms or lvc alarms and a C.A. Oh a couple cell meters. Big tip solder iron 60watt for making wiring harness. Check and cycle each pack before assembly. Read lipo build threads .
After that you check packs again befoe assembly. Can be bulk charged id monitored. Dont even over discharge.
 
slickenned said:
ill look at lipo pages for warning and stuff, but any quick notes i should be concerned about? or is there a post on this forum for the ins and outs of lipo you can link me to? you guys are awesome, everyone who has sent replies. thank you so very much for your insight and for putting up with my verboseness :D

if this all works out ill post some photos. wont be anything super fancy but might help someone else doing something similar

If you're going 5 x 4S, then the biggest thing you need to worry about is not running the batteries too low, because while the charger won't over charge, the bike will happily keep running thinking the battery is 20-25% full, when in fact it's almost empty. That's not a stranded on the side of the road kind of thing. If you drain the battery too low, it starts slowly gassing (reverse of lead acid). From that minute on, you start losing capacity permanently, after a few hours, it'll start to puff. If you don't get it charged back in less than a day, your investment is completely wasted, and becomes a fire hazard.

I would personally recommend a few things:

1. Make a wiring harness, so you can keep your packs as 5 x 4S, rather than make a 20S pack.
2. Get balancing charger - although a small detachable balancer is cheaper, but a LOT more work. Balancing chargers are about $40-100, detachable balancers are about $5-10. Will post links when I'm in front of a computer
3. Get a low voltage alarm. This is because now that the battery is slightly higher voltage than the bike expects, you need another method to warn you that your pack is almost flat. These are also about $5-10

4S is the ROAR official size for RC car competitive racing, hence why they are so cheap (bulk production). It also means most budget chargers, balancers, etc, are most commonly available up to 4S. Just out of interest, 6S is the most common size for amateur drones, again, hence why I said 3 x 6S is another common and cheap way to do things.
 
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