I have a batterypack with 9 gen1 Nissan Leaf modules. It's winter now and temperature lays around -10⁰C. After what I have read it's not adviseable to charge the battery when it is so cold so I wonder if you know of something that is keeping the battery warm, or over 0⁰C, when charging? I want something that is safe to leave over the battery for a few hours.
Battery warmer
- Thread starter jai134
- Start date
If you have space, you can insulate the whole battery pack to hold heat in better, and install thin "terrarium" heating pads (similar to those Zilla and other companies make)
on all sides, then connect them in parallel to a temperature-controlled power strip like these:
and install the sensor from the strip inside the pack, putting a connector on the wire from it to the strip (it's hardwired as it comes from the factory) to prevent overheating.
It's made with separate sensors for separate outlets and independent control settings for each, so if you're willing to modify the strip you can set it up so that the relays inside control just one outlet (one on neutral and one on hot), then both sensors can be installed in the pack to monitor two different locations, and either one reaching the limit you set will turn off all heaters.
Or if you wiire up half the heaters to one outlet, and half to the other, each sensor can be placed to monitor one set, and each one then shuts off that half of the heaters when the limit is exceeded.
If you need to, you can wire them in series (instead of parallel) so they are more limited in output power, if they heat up too fast.
on all sides, then connect them in parallel to a temperature-controlled power strip like these:
and install the sensor from the strip inside the pack, putting a connector on the wire from it to the strip (it's hardwired as it comes from the factory) to prevent overheating.
It's made with separate sensors for separate outlets and independent control settings for each, so if you're willing to modify the strip you can set it up so that the relays inside control just one outlet (one on neutral and one on hot), then both sensors can be installed in the pack to monitor two different locations, and either one reaching the limit you set will turn off all heaters.
Or if you wiire up half the heaters to one outlet, and half to the other, each sensor can be placed to monitor one set, and each one then shuts off that half of the heaters when the limit is exceeded.
If you need to, you can wire them in series (instead of parallel) so they are more limited in output power, if they heat up too fast.
Thank you so much! Your solution is really good but I think the problem with it, as you say, is space for the insulation. I moved everything from my motorbike (except the throttle) to my garden tractor (I need something to plow snow with) and I filled the space where the engine was quite thorough, so there is not much room under and on the sides of the battery for styrofoam or similar material. What do you say about laying a car seat warmer over the battery pack? Perhaps adding a piece of cardboard as outer layer to keep the heat.
I think the problem is to create a permanent solution. I didn't think of this when I made the mounts for battery, motor and controller so this winter I need something only when charging.
I think the problem is to create a permanent solution. I didn't think of this when I made the mounts for battery, motor and controller so this winter I need something only when charging.
Last edited:
I don't know what a car seat warmer is capable of or what temperature control it has (if any). The human body has it's own temperature regulation by circulating blood around to move heat around, and shed it or retain it at the skin, so if the seat warmer is low enough wattage it would not need any temperature control. But the battery can't do this, so whatever parts of it are next to the warmer will get warm (or hot) and the rest of it will not change temperature at all or will do so slowly over time as heat conducts to the rest of the battery from the warm / hot parts.
Anything that only contacts part of the battery will have the same issue, though if it has temperature monitoring you can install on or in the battery, then with it's control you can at least set it to not overheat it.
As long as the temperature never gets too high for the battery itself, and you have time to wait for the battery to all reach the right temperature, then it wont' matter if the heat only starts on one part of the battery.
The reason I recommended the terrarium / reptile heating pads is they are tough rubber, flat, and thin (a few mm), and come in various sizes, so can be placed on all sides of a battery. They all run off regular wall AC voltage, so they can be used with those temperature controlled power strips (since they don't ahve temperature controls of their own) if necessary.
Even if you can't insulate the pack, they'll still be a more consistent solution than something that just covers the battery area.
BTW, they also make battery warmers for car starter batteries; these are typically similar to the other pads, and are meant to be left plugged in and on to keep the battery warm and unfrozen in bad weather. They may work for your purpose too.
Anything that only contacts part of the battery will have the same issue, though if it has temperature monitoring you can install on or in the battery, then with it's control you can at least set it to not overheat it.
As long as the temperature never gets too high for the battery itself, and you have time to wait for the battery to all reach the right temperature, then it wont' matter if the heat only starts on one part of the battery.
The reason I recommended the terrarium / reptile heating pads is they are tough rubber, flat, and thin (a few mm), and come in various sizes, so can be placed on all sides of a battery. They all run off regular wall AC voltage, so they can be used with those temperature controlled power strips (since they don't ahve temperature controls of their own) if necessary.
Even if you can't insulate the pack, they'll still be a more consistent solution than something that just covers the battery area.
BTW, they also make battery warmers for car starter batteries; these are typically similar to the other pads, and are meant to be left plugged in and on to keep the battery warm and unfrozen in bad weather. They may work for your purpose too.
Where I'm located, it's not unusual to experience single digit temps occasionally. What i've done for years, is cover the engine bay with a used or discarded blanket. Then simply place a typical 100w incandescent lamp on the ground below the engine. Focused 'Spot' lamp bulbs aimed upwards seem to work even better.
That's something I have to try! Thank you
Doesn't get that cold here, but on freezing nights I used that method with SB Cruiser's oriignal cargo/seatbox design that had an open channel in the middle for the chain to pass thru and be accessed from (it's now closed up underneath to delay / minimize water ingress in flashflood waters so the heat can't get up inside this way). I only used a 7-10w incandescent in a spotlamp type housing, though, and it kept the temperature at least a dozen degrees above ambient, along with the 1/2" - 1" styrofoam insulation inside the wooden box.
These days when it gets that cold (probably next month) I use a couple of those small reptile heaters, wired in series to reduce the total power, one in front of the battery and one behind it, heating the edges of the (pouch) cells. They keep the pack at room temperature overnight, and it performs much better than when it's cold (even 60F reduces available power from it as it's over a decade old now).
My charger (600w+, fanless potted) is mounted directly under the battery outside the box, too, so it does pass some heat into the box and battery, but not all that much due to the 3/8" of plywood and 1/2" of styrofoam between them.
These days when it gets that cold (probably next month) I use a couple of those small reptile heaters, wired in series to reduce the total power, one in front of the battery and one behind it, heating the edges of the (pouch) cells. They keep the pack at room temperature overnight, and it performs much better than when it's cold (even 60F reduces available power from it as it's over a decade old now).
My charger (600w+, fanless potted) is mounted directly under the battery outside the box, too, so it does pass some heat into the box and battery, but not all that much due to the 3/8" of plywood and 1/2" of styrofoam between them.
Last edited:
