This video was about an ICE camper, but gives a great solution, I think:
How to find charge specifications for 12v batteries/APM's for camping purposes?
Hi,
Just stumbled upon this forum while searching on Google.
My girlfriend and I bought an E-208 4 months ago and we're really happy with it. She uses it every day to go to work and with the current hike in gas prices we're even happier that the car might be able to pay itself home just by not having to fill up the tank with gas.
A couple of years ago we bought a diesel van and converted it to a campervan to test if we like that kind of weekend leisure/holiday. We love it, but already at that time we knew that our final goal would be an ev of some sort....
Long story short, we're searching for a second EV for camping purposes. Either an e-van or a bigger e-car to put a tent on the roof, but here comes the hurdle I didn't think was that big of a problem.
There's not much information on how the EVs are charging its 12v battery and with how many amps. We would like to be able to be drawing 2 kw overnight for heating during winter/ski season and whatsoever, but it seems like this is still a grey area in the EV segment.
THE QUESTION:
How to find out which EV charges the 12v battery with how many amps and if it does it without being switched on?
Just stumbled upon this forum while searching on Google.
My girlfriend and I bought an E-208 4 months ago and we're really happy with it. She uses it every day to go to work and with the current hike in gas prices we're even happier that the car might be able to pay itself home just by not having to fill up the tank with gas.
A couple of years ago we bought a diesel van and converted it to a campervan to test if we like that kind of weekend leisure/holiday. We love it, but already at that time we knew that our final goal would be an ev of some sort....
Long story short, we're searching for a second EV for camping purposes. Either an e-van or a bigger e-car to put a tent on the roof, but here comes the hurdle I didn't think was that big of a problem.
There's not much information on how the EVs are charging its 12v battery and with how many amps. We would like to be able to be drawing 2 kw overnight for heating during winter/ski season and whatsoever, but it seems like this is still a grey area in the EV segment.
THE QUESTION:
How to find out which EV charges the 12v battery with how many amps and if it does it without being switched on?
1 - 14 of 14 Posts
This is actually what we are currently doing with our ICE van and I believe that's the way most people charge their leisure batteries in their ICE vehicle.
My question was more in terms of the courant an EV charges its 12v battery and if it does it even when it's turned off.
Ex. During ski season we would like to be able to switch out our diesel heater with an electric heater. This, however, implies that the car can give a stable 12v current of 2kw or so for an extended amount of time.
The traction battery itself could sustain it no problem, but can the dc-dc charger? This surely depends on the EV and was wondering where we could get that kind of information.
My question was more in terms of the courant an EV charges its 12v battery and if it does it even when it's turned off.
Ex. During ski season we would like to be able to switch out our diesel heater with an electric heater. This, however, implies that the car can give a stable 12v current of 2kw or so for an extended amount of time.
The traction battery itself could sustain it no problem, but can the dc-dc charger? This surely depends on the EV and was wondering where we could get that kind of information.
2kw is going to drain your traction battery rather fast, isn't it? I think I would stick with the diesel heater.
2kW @ 12v = 167A, which is probably a lot more than the traction battery to 12V dc-dc converter can handle.The traction battery itself could sustain it no problem, but can the dc-dc charger?
Even traction batteries on smaller cars such as the E-208 contain 48kwh. This means that I could potentially run a 2kw heater for full throttle for 24 hours. Still, 2kw heating might only be used in very low temperatures. For example is a 2.5kw diesel heater more than enough to heat an entire van in -18C2kw is going to drain your traction battery rather fast, isn't it? I think I would stick with the diesel heater.
That's why I would like to know where to find such information. It is not unheard of having car alternators delivering 150 amps and I read somewhere that the old Nissan Leaf models could charge their 12v battery with 1.8kwh whereas the new ones could charge it with 1.2kwh.2kW @ 12v = 167A, which is probably a lot more than the traction battery to 12V dc-dc converter can handle.
Even 1.2kwh could work out if I plugged in a 400 ah lithium ion 12v leisure battery as it could help to keep up the power drain on really cold nights.
I doubt very much that any EV DC-DC converter is designed to supply even 100amps for any length of time. They are intended to replenish normal 12v usage by the electronics, and other 12v equipment and an occasional top up when the EV is parked up.
For an indication what is the fuse rating on the output of you dc-dc charger?The traction battery itself could sustain it no problem, but can the dc-dc charger?
I'm afraid of that as well, but had hoped to find some datasheets confirming it. That said, ICE cars don't need much 12v battery power either afaik. Just a short, but powerful burst in the beginning and the rest is more or less same levels as an EV. I would even say that the average EV might use more 12v power as they tend to have many more electronic gadgets.I doubt very much that any EV DC-DC converter is designed to supply even 100amps for any length of time. They are intended to replenish normal 12v usage by the electronics, and other 12v equipment and an occasional top up when the EV is parked up.
Wonder why alternators on ICE cars are so over-dimensioned though. Maybe because they can only charge the battery while the engine is running?
This is not a bad idea. We should be able to find fuse diagrams on the internet for different cars to get an idea of their DC-DC charger size.For an indication what is the fuse rating on the output of you dc-dc charger?
Still, we wouldn't know whether it can charge when the car is off or if it's only charging when plugged in etc.
The entire purpose of this, is to not avoid the warranty by retrofitting another DC-DC charger. EVs tend to be a little expensive to break
ALL 12v power on an ICE is provided by the alternator in addition to it charging the battery back up after starting..I'm afraid of that as well, but had hoped to find some datasheets confirming it. That said, ICE cars don't need much 12v battery power either afaik. Just a short, but powerful burst in the beginning and the rest is more or less same levels as an EV. I would even say that the average EV might use more 12v power as they tend to have many more electronic gadgets.
Wonder why alternators on ICE cars are so over-dimensioned though. Maybe because they can only charge the battery while the engine is running?
On an EV the 12v battery is much smaller (~40-50AH) because there is no starting requirement. ALL power comes from the traction battery so this is equivalent to the alternator on an ICE.
You aren't going to get kw out of the traction battery for heating without drastic loss of range. You'd need to park up at a public charger every day to keep it charged.
40-50Ah is what a Reanult Clio uses as well and the reason is rather that it has to be able to give a high power burst for 2 seconds at startup. Not because it needs all that capacity, but because a smaller capacity lead acid battery can't handle these power bursts. This is also why you can get 25Ah li-ion batteries for your ICE car which will do just fine as li-ion have can handle higher currents. Furthermore, lead acid batteries do very poorly in lower temperatures.ALL 12v power on an ICE is provided by the alternator in addition to it charging the battery back up after starting..
On an EV the 12v battery is much smaller (~40-50AH) because there is no starting requirement. ALL power comes from the traction battery so this is equivalent to the alternator on an ICE.
You aren't going to get kw out of the traction battery for heating without drastic loss of range. You'd need to park up at a public charger every day to keep it charged.
The traction battery is usually only used for the electric motor and the air-conditioning. The rest is dealt with using the 12v battery, which again comes to my reasoning that EVs and ICE cars might have the same 12v battery requirements in terms of constant current while driving.
Even a small car like the E-208 have 48kWh of usable capacity which is plentiful for heating purposes. As stated above, we currently use a 2.5 kWh diesel heater, and even at -18C it has no problem heating up an entire van.
If we go skiing for an extended weekend, we would usually arrive around 10am at the ski station and go directly skiing and then come back around 5pm. This means heating between 5pm to 10am the next day which translates to 17 hours of heating. During night we don't need 20C inside so let's say the heating will average 1kWh on very cold days.
If we do this for two days in a row, we have roughly used 34 kWh of the 48 kWh. 14kWh or 30% left should be enough to go to and from the nearest charging station.
Staying a place for more than two days is usually at camp sites that have electricity or at summer where no heating is necessary.
Hi @KristerBC,
Did you find the answer to your question? Did you advance with your EV camper plans? It would be great if you could share any information you have.
Did you find the answer to your question? Did you advance with your EV camper plans? It would be great if you could share any information you have.
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