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Hi guys,

So I'm just planning the electrics system for my e-NV200 camper conversion and has a thought...

In the past (in ICE campers) I've always used leisure batteries for the camper electrics, charged from the alternator via a battery-to-battery charge system (as well as solar and a 230v mains charger). But, in an electric vehicle, is there any reason I can't use the 12v under the bonnet?

Conventionally, the starter battery in an ICE vehicle will deliver a high surge current to start the engine, but won't like being deep discharged. Your leisure battery is the opposite and won't deliver a huge surge current, but will be more tolerant to bring deep discharged. So as far as I can see, the main reason for using a specific leisure battery as opposed as a starter battery, for your camper electrics (other than the obvious reason of not draining your starter battery whilst camping) is because the two batteries are actually different technologies (one for high surge low discharge, and the other for low surge but high discharge)

So it got me thinking... why can't I replace the 12v battery under the bonnet of my e-NV200 with a high capacity battery (maybe AGM or lithium) of 200Ah, and use that to provide 12v power to both the vehicle, and the camper 'leisure' electrics?

Our EVs don't pull a surge current from the battery when they start - they just use the 12v to keep systems running and boot up the vehicles drive systems etc. So if there's no surge current required, a 'leisure' type battery should be able to replace the factory 12v, no?

The benefits that I can see are:
*Only one 12v needed in the vehicle rather than 2, saving weight and space.
*No battery-to-battery charger or split charge relay required.
*No additional 230v mains charger required for the leisure battery, as the 12v charges when we plug the vehicle in (I assume?)
*There's plenty of space under the bonnet to fit the inverter and solar charge controller.

The only negative I can see is that you'd need to ensure that you don't drain the battery (rendering you unable to start the vehicle). Or does the vehicle sense when the 12v is low, and charge it via the DC-to-DC, automatically? Either way, you can fit a voltage sensitive relay, that cuts power to the 'leisure' system when the battery gets to a certain percentage state of charge, to ensure that there's always power available to start the vehicle.

Any thoughts on this? I'm sure many of you guys are far more clued up than me

Sent from my HD1903 using Tapatalk
 

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Hi guys,

So I'm just planning the electrics system for my e-NV200 camper conversion and has a thought...

In the past (in ICE campers) I've always used leisure batteries for the camper electrics, charged from the alternator via a battery-to-battery charge system (as well as solar and a 230v mains charger). But, in an electric vehicle, is there any reason I can't use the 12v under the bonnet?

Conventionally, the starter battery in an ICE vehicle will deliver a high surge current to start the engine, but won't like being deep discharged. Your leisure battery is the opposite and won't deliver a huge surge current, but will be more tolerant to bring deep discharged. So as far as I can see, the main reason for using a specific leisure battery as opposed as a starter battery, for your camper electrics (other than the obvious reason of not draining your starter battery whilst camping) is because the two batteries are actually different technologies (one for high surge low discharge, and the other for low surge but high discharge)

So it got me thinking... why can't I replace the 12v battery under the bonnet of my e-NV200 with a high capacity battery (maybe AGM or lithium) of 200Ah, and use that to provide 12v power to both the vehicle, and the camper 'leisure' electrics?

Our EVs don't pull a surge current from the battery when they start - they just use the 12v to keep systems running and boot up the vehicles drive systems etc. So if there's no surge current required, a 'leisure' type battery should be able to replace the factory 12v, no?

The benefits that I can see are:
*Only one 12v needed in the vehicle rather than 2, saving weight and space.
*No battery-to-battery charger or split charge relay required.
*No additional 230v mains charger required for the leisure battery, as the 12v charges when we plug the vehicle in (I assume?)
*There's plenty of space under the bonnet to fit the inverter and solar charge controller.

The only negative I can see is that you'd need to ensure that you don't drain the battery (rendering you unable to start the vehicle). Or does the vehicle sense when the 12v is low, and charge it via the DC-to-DC, automatically? Either way, you can fit a voltage sensitive relay, that cuts power to the 'leisure' system when the battery gets to a certain percentage state of charge, to ensure that there's always power available to start the vehicle.

Any thoughts on this? I'm sure many of you guys are far more clued up than me

Sent from my HD1903 using Tapatalk
Lots on this in earlier threads - have a search for "env camper", Glyn Johnson is your man!
 

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This question takes me back to motor caravanning with my father in the 80's. We had a Mercedes 206D conversion. (50mph on a good day with the wind behind you!) :)

126770


There was a split charge system in that, and we made the mistake of leaving the 12v fridge running on the battery overnight. Next morning there was not even enough energy in the camping battery to engage the solenoid on the rear cassette player to hold the tape in.

I would not want to be in that position with the starting battery, so I think a separate camping battery is still preferable.
 

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Discussion Starter #4
Lots on this in earlier threads - have a search for "env camper", Glyn Johnson is your man!
Ah yes, sorry. I'd read Glyn's whole thread previously and then forgotten about it. Now I've re-read, I see he's pretty much answered must of my questions!

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Discussion Starter #5
This question takes me back to motor caravanning with my father in the 80's. We had a Mercedes 206D conversion. (50mph on a good day with the wind behind you!) :)

View attachment 126770

There was a split charge system in that, and we made the mistake of leaving the 12v fridge running on the battery overnight. Next morning there was not even enough energy in the camping battery to engage the solenoid on the rear cassette player to hold the tape in.

I would not want to be in that position with the starting battery, so I think a separate camping battery is still preferable.
Haha, well I'd definitely want to install a low voltage cut off, to stop this from happening.

But I could definitely imagine myself draining the battery accidentally, in your situation

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I’d avoid lithium (LiFePO4) unless you buy a decent brand that can handle being charged at up to 80 amps or more. The DC-DC converter in the e-NV200 is designed for flooded lead acid and the cheaper “drop in” lithium batteries for wheelchairs have simple BMS systems that can’t handle this type of use.
The same sort of goes for AGM too, as they do have a slightly different charge requirement for longevity, but for leisure use they are better than flooded.
I have a cheap LiFePO4 battery in my camper as a second battery, the starter battery is still flooded lead acid.
It’s charged using its own charger and is only charged when the van is on.
I’ve had it for about 6 years now and it’s still as good as it always was. I did once try charging it with an alternator on my old van and the BMS put the battery into protection mode once it was fully charged.
Obviously that wouldn’t be good in a van while it’s driving as who knows what would happen if suddenly the battery switched itself off.
 
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