Lifepo4 in the garage

[mythprod]

I've tried multiple searches for this as I'm sure it's been answered already a bunch of times before (kept getting results related to over-charging and exploding batteries, etc.).

I have the option of bringing the bike into the house at night and during the day when it's hot (if necessary) but leaving it in the garage would be more convenient. I have a 1000w motor hooked to a 48v 20ah lifepo4 battery, I know the performance will degrade in cold weather but is the battery generally safe in the garage at -4 to 110+ degrees fahrenheit? I've read temperature ranges for lifepo4 are -20 to 60°C so if I understand that correctly then the battery will be safe being kept in the garage?

TIA!

 

[dnmun]

yes

 

[dogman dan]

Some will say no, but I kept a 36v 20 ah pingbattery charging in the garage which can easily reach 120F for 3 summers. When the battery died last summer, it was my fault. After riding home sporting a body temp of 104, I left the controller turned on, went inside and enjoyed west nile virus for a few weeks.

At that time, the battery had 700 cycles on it, and still had about 80- 90% capacity.

So far as I could tell, no harm that I gave damn about. I worried when I first got the battery, about charging right when I got home and the battery would be at the ambient temp of 105F. Then I looked up the operating temperature range of lifepo4, and realized I'd be dead at the lifepo4's upper temp limit.

I was worried because I had learned the hard way, to let nicads cool off before charging them. Nicads heat up more during charge, so they need to start out cool.

On the other end of the spectrum, in winter you will find it worthwhile to start your ride with a warmer battery. My pings would drop capacity a lot if the box got below 32F. It was noticeably sagging more just at 50F. So overnight, you might want to bring the battery inside, so you at least start the ride with a 60F battery.

 

[Lebowski]

On the other end of the spectrum, in winter you will find it worthwhile to start your ride with a warmer battery. My pings would drop capacity a lot if the box got below 32F. It was noticeably sagging more just at 50F. So overnight, you might want to bring the battery inside, so you at least start the ride with a 60F battery.

'd be interesting to see if, in cold weather, a small resistive heater heating the pack will bring more capacity than it uses....

 

[Ypedal]

for long term storage, cool temps are good.

for daily usage, as dogman pointed out, bring them inside if temps are near freezing.. for charging and to have them warm when you leave for a ride.

warm/hot batteries perform better ( chemical reactions ), but too much heat leads to problems... generally .. batteries are tougher than you, if you can take the ambient temp, they can too.. otherwise.. best to stay home in AC and drink cold beer.

 

[dogman dan]

Not that cold where I live. Nor will I ride anymore if it's below 20F. Screw it, drive the car now that I can afford it again. 15 miles is a long ride below freezing. 5 miles can be done in any weather though.

But when I did ride it, just starting out with a warmish battery, and insulating the box was good enough. The battery will very slightly warm itself as you discharge. Part of why I constantly say buy too much battery is because you will have less in freezing weather.

Dogmans 36v rule of 1 ah per mile takes that into account.

Reptile heaters would be ideal to warm a battery that must stay in the garage in winter. Waterproof, and just the size of a lifepo4 pack.

 

[john7700]

I rode my ping 36/20 often in sub-freezing weather (New England) and as far as I could tell, having a warm battery to start with helped for about five minutes. After that, it sags like a big dog. 4-5 MPH off the top and greatly reduced range. If you were to use a heating pad, you would also need a very well insulated box that preferably was also warm to start.

Ice fishing the frozen Conn. River with studded tires:

 

[dogman dan]

Yes, you'd need serious insulation to avoid sag in that weather. Where I live, we freak out if it doesn't reach 50 F by afternoon, even in january.

Maybe better insulation, and a brick taken from the oven.

 

[hoppydawg]

what about an insulated cooler bag? I live in Rhode Island and will be storing my bike in an unheated but insulated garage. My battery/(steel ammo) box is bolted to the rear rack of my cargo bike. I will be charging with the battery in the box and the lid open. I have a 36v/15ah ping lipo and will be commuting between 5/14 miles RT.

 

[mythprod]

Been riding since august with no battery problems. I did some reading around on other sites and the consensus seems to be discharge in just about any temp the battery can take, but charge in the house if possible. It's fairly convenient for me to do that so no problem.

I'm struggling a bit at what I want to draw the line at in temp before I retreat back to the car. I have no interest in riding on moisture but most of the time I don't have to compromise as it stays fairly dry, so really it's just how cold is too cold. For me I feel it in the face, ears and arms first. I did a test today and found that with sweats under jeans my legs were fine in 25-30 degree weather for about 30-45 minutes. I wore a t-shirt, hoodie and ski coat and my core was fine. I only wore knit gloves and that worked for most of the time, tail end of my ride my hands / fingers started feeling it. I did have to pull my hoodie up and adjust my bike helmet to be on top of the hoodie, my ears couldn't take much riding at those temps. I'm thinking of getting a Balaclava, probably will solve my issues. As far as running the battery in those temps or colder for my 13 mile ride to work, I haven't decided.

P.S. Cotton makes me sweat pretty bad, a side-effect of not purchasing the proper gear for winter cycling I guess.

 

[999zip999]

In winter time people forget about there battery and the bms can discharge part of it ect. If not in use I would unplug the bms or charge once a month.

 

[dogman dan]

You sound pretty tough, I wore a lot more to ride in 30 F. Since I used to do a lot of skiing, clothes were not a problem. Same stuff worked great, ski gloves, nylon shell overpants and coat, then layers underneath as needed. The snowboard helmet was nice, since it had no vents and some warm earflaps. Good wrap around glasses help the forehead and eyes keep warm. Big mr maggoo style ones made to go over glasses work great.

But I did find that if it wasn't going to be 50F for the ride home, I didn't get much joy out of the ride home. So after the second year I began to drive the car more if it was really cold for here, like 20F.

Ideally, charge the battery in a warm place, with the battery warm. But a warmed battery just discharged can be plugged in in cold weather, if it will soon be above freezing.

 

[mythprod]

I went ahead and brought the bike in when I'm not riding it. I could keep everything else in the garage and just bring in the battery but I've invested enough into the bike now I'd rather the bike just be indoors and warm when not in use. Plus undoing the bungee cords I have around the battery and rack is a little bit of a pain when done twice a day. I'm hoping keeping everything indoors (including the charger) will help with my bad charger woes. The ping charger I purchased recently is still holding up but I noticed it gets a lot hotter than my first two chargers. Not a problem per se, just a difference I'm noticing. Tomorrow I may confirm the fan isn't installed backwards or something silly like that.

The overpants sound like a good idea, easy to get on and off and wind / water resistant. I've got a shot at picking some up at a thrift store too so maybe I'll keep my eyes open. I've got a balaclava for the head and face which helps but I'm hoping a face mask I have on order (under the balaclava) will help keep the wind off of my cheeks and ears, where I feel it the most. I use ski coat and gloves and they work well. I'm pretty sweaty when I get to work though so I'm going to have to figure something out to minimize that if possible. I'm a sweater and I pedal pretty good while riding so some sweat is inevitable I'm sure.

 

[dnmun]

polypro for the cold. the fan on the ping charger is not running? it is a DC fan but it was installed correctly without doubt.

the bearings get sticky and dry out so you can make the fan run again by taking a razor and picking up that round paper seal on the end of the fan, sometimes there is a rubber plug underneath to remove too, but that gets you to the bearing, use light silicone oil if you can find it, but i just use 3 in 1 since that is all i have.

after you get some oil in the recess around the shaft, put the rubber plug back down. wipe off the oil that dribbled over from the face of the fan so the paper circle will stick back down on the end. clean it with solvent if needed, and if you need glue to seal that paper circle then use it to hold the paper seal on the end of the fan.