Anyone installed a large 12VDC to 220V AC Inverter in a MG5?

[n8sail]

I would like to put a relatively large DC-AC inverter into my MG5 so that I can have 'mains' plugs to run vacuum cleaner etc. when working on my boat, which does not have a 'mains' nearby without many many meters of extension cords. There is plenty of room in the bonnet on the Thai version of the car, we don't even have a cover in it at all, just two empty brackets and wide open space.

Running the inverter off the 12VDC Battery with the car in 'camping' mode so that High Voltage Battery is charging the Low Voltage battery should allow me to run AC loads for many hours. I'm thinking a modern 2-3k watt so that I can run power tools for short periods would probably be okay, with the low voltage battery providing 'overflow' current for starting motors etc.

Anyone tried this yet?

 

[aread2]

At 3kW you'd be drawing over 250 amps at 12v. I'd be very surprised if the wiring and 12v charger under the bonnet could sustain that kind of load for more than a few seconds.

 

[n8sail]

At 3kW you'd be drawing over 250 amps at 12v. I'd be very surprised if the wiring and 12v charger under the bonnet could sustain that kind of load for more than a few seconds.

I would connect it directly to the 12Vdc battery, the car really wouldn't know it's there. Any current needed over what the vehicle's on-board 400vdc-12vdc converter can supply should be delivered by the car's 12vdc battery, no? The Car's DC-DC converter will just keep pushing out its set current regardless.
3000 watt inverters normally can only supply that for a few seconds (for starting motors etc), the one I'm looking at can do 1500 watts continuous, so about 125amp at 12VDC.

 

[Alb]

The DC-DC Converter output is rated 178A@14V, so nominally around 2.5kW.
I'm not sure if the battery cables are rated at this level.

 

[aled]

I have been looking into this. There is a 150A fuse for the dcdc converter (in the fuses next to the battery). Since it runs at ~14V the whole load will likely run through this. So maybe get a 120a circuit breaker or a spare 150a fuse before going near that power level.

 

[n8sail]

I have been looking into this. There is a 150A fuse for the dcdc converter (in the fuses next to the battery). Since it runs at ~14V the whole load will likely run through this. So maybe get a 120a circuit breaker or a spare 150a fuse before going near that power level.

Yes, a 150A fuse would be a good idea from battery to the inverter itself.
At 178A, the DC-DC converter is basically as powerful as a larger car Alternator, which should easily power an inverter like this.

Glad I'm not the only one thinking about this. Thanks guys!

 

[aled]

Yes, a 150A fuse would be a good idea from battery to the inverter itself.
At 178A, the DC-DC converter is basically as powerful as a larger car Alternator, which should easily power an inverter like this.

Glad I'm not the only one thinking about this. Thanks guys!

I meant that < 150 amp fuse/circuit breaker would be best as that would mean the 150 amp fuse in the car would not blow.

 

[BugEyed]

What would be the cost of changing to the newer version that has V2L as standard?

 

[n8sail]

What would be the cost of changing to the newer version that has V2L as standard?

A heck of an lot more than a ~$70 inverter, some mounting hardware, wire, terminals and a fuse

Plus I can do all this within a weekend.

Also, we don't even have the long range version here in Thailand yet, so one can be certain the next version with V2L will be ages away. We're allowed our dreams though, I guess

@aled yes understood that the fuse should be slightly smaller rating than the existing one in the car itself. That way I'm more or less guaranteed to not damage the car (provided the fuse does its job as stated on the package)

 

[aled]

@n8sail Ahh good. At least there is a replaceable fuse for if it goes wrong. Also if you look inside your inverter you will probably find it has standard blade fuses in parallel which you may be able to swap for lower rated fuses. This may give you more flexibility since blade fuses are easy to find in a range of ratings.
Oh and one of the people who fitted a frunk to the Sr said what size bolts to use for mounting using the 4 fixing points on top of the motor.
To leave higher power as a future option I went with a 3kw psw inverter so that if I do want more than 1.5kw in the future I can put in a battery to battery charger and either a few lead acid batteries or some l-ion leisure batteries.
I just need to get round to fitting my inverter in the car now.

 

[Hairyfool]

And make sure you have a jump start pack available to activate the car in case the DC-DC converter shuts down and you end up flattening the vehicle 12v battery. If the fuse goes when busy on the boat you wouldn't really know until the inverter shuts down. Most automotive orientated inverters are able to shut off when the on load voltage falls to a preset level to leave the ability to start an ICE vehicle.

To be honest I would look at battery powered vacs using packs from one of the better know power tool brands such as Makita (my preferred), deWalt or Milwaukee. That way battery packs for the vac will also power drills, sanders etc.

 

[n8sail]

And make sure you have a jump start pack available to activate the car in case the DC-DC converter shuts down and you end up flattening the vehicle 12v battery. If the fuse goes when busy on the boat you wouldn't really know until the inverter shuts down. Most automotive orientated inverters are able to shut off when the on load voltage falls to a preset level to leave the ability to start an ICE vehicle.

To be honest I would look at battery powered vacs using packs from one of the better know power tool brands such as Makita (my preferred), deWalt or Milwaukee. That way battery packs for the vac will also power drills, sanders etc.

Indeed that's a good idea. I'll make sure to read the friendly manual of the Inverter to see what it does in low-voltage situations. I suspect these modern ones all have a shut-off.

Does anyone know what voltage the 12vdc battery has to go below before the MG5 won't start? I imagine a bit lower than an ICE car as all it needs to do is close some high voltage relays, power on lights/computers etc. Certainly some draw but nothing compared to the hundreds of amps required to turn-over an engine. Additionally, large amount of Cold-Cranking Amps not really required, either.

I have looked into battery-powered wet/dry vacuums here; unfortunately there is only one cheapo Chinese brand that I have found so far. The big power tool brands here in Thailand don't seem to import their cordless wet/dry vacuums. The Chinese one only has 200w motor, so not very powerful compared to the 1000w plug-in one that I have already. Also, even though it's 'cheap', it costs more than the inverter itself! An excellent suggestion though.

 

[ZSDave]

I would like to put a relatively large DC-AC inverter into my MG5 so that I can have 'mains' plugs to run vacuum cleaner etc. when working on my boat, which does not have a 'mains' nearby without many many meters of extension cords. There is plenty of room in the bonnet on the Thai version of the car, we don't even have a cover in it at all, just two empty brackets and wide open space.

Running the inverter off the 12VDC Battery with the car in 'camping' mode so that High Voltage Battery is charging the Low Voltage battery should allow me to run AC loads for many hours. I'm thinking a modern 2-3k watt so that I can run power tools for short periods would probably be okay, with the low voltage battery providing 'overflow' current for starting motors etc.

Anyone tried this yet?

I've not tried running an inverter from the car battery but I have had experience of inverters, first of all on a canal narrowboat and then in a motorhome. The one thing I will say is make sure you go for a pure sine wave inverter, as most modern electronics are not happy with a modified sine wave. At best they can refuse to run and at worst they can totally ruin the electronics.

Dave

 

[n8sail]

I've not tried running an inverter from the car battery but I have had experience of inverters, first of all on a canal narrowboat and then in a motorhome. The one thing I will say is make sure you go for a pure sine wave inverter, as most modern electronics are not happy with a modified sine wave. At best they can refuse to run and at worst they can totally ruin the electronics.

Dave

Definitely will. Luckily pretty much all inverters now are PSW.

I do remember the days of the sawtooth or square wave old-school inverters. Nightmare to run anything sensitive like audio or sensor equipment off of.

 

[ZSDave]

Definitely will. Luckily pretty much all inverters now are PSW.

I do remember the days of the sawtooth or square wave old-school inverters. Nightmare to run anything sensitive like audio or sensor equipment off of.

Just had a look on Amazon (UK) and less than 50% on there are pure sine wave inverters. PSW inverters are not cheap either. Good luck with your project.

Dave

 

[n8sail]

Just had a look on Amazon (UK) and less than 50% on there are pure sine wave inverters. PSW inverters are not cheap either. Good luck with your project.

Dave

I guess i should rephrase that... Most of the ones I see available here in Thailand claim to be PSW... So whether or not they actually are is another issue. Consumer protection, especially for an expat, is virtually non-existent here. Defamation laws are insane here as well, so Buddha help you if you leave a bad review about something online.

 

[aled]

I guess i should rephrase that... Most of the ones I see available here in Thailand claim to be PSW... So whether or not they actually are is another issue. Consumer protection, especially for an expat, is virtually non-existent here. Defamation laws are insane here as well, so Buddha help you if you leave a bad review about something online.

I went with renogy for a psw inverter as I could at least find consistent real reviews about them. They weren't much more than the equivalent specification cheaper models. I did still use amazon though as apparently the customer service/refunds are not as easy if you order direct.

 

[Hairyfool]

The fact is no wet cell lead acid battery should be taken below 50% SOC as significant damage to its capacity will occur. However I doubt the electronics will take that into account.

Also a virtually flat battery will register over 11.5v on a meter off load but the voltage will rapidly collapse as soon as any current is drawn from it.

A fully charged battery will register 12.6v off load and rested but a battery can be fully charged AND have almost no actual storage capacity due to age or excessive discharges.

These issues can make it very complicated to really know the condition of a battery without specialist test equipment.

 

[n8sail]

The fact is no wet cell lead acid battery should be taken below 50% SOC as significant damage to its capacity will occur. However I doubt the electronics will take that into account.

Also a virtually flat battery will register over 11.5v on a meter off load but the voltage will rapidly collapse as soon as any current is drawn from it.

A fully charged battery will register 12.6v off load and rested but a battery can be fully charged AND have almost no actual storage capacity due to age or excessive discharges.

These issues can make it very complicated to really know the condition of a battery without specialist test equipment.

Thanks, I'm well aware of limitations and best practices using the various Lead Acid battery types. I've been sailing/cruising for decades with Lead Acid batteries, sealed and un-sealed using nothing more than a multimeter and the 'resting voltage' as indicator of State of Charge. Haven't been stuck with a dead battery yet knock wood

I would certainly be checking the battery often the first few times I put a heavy load on it.

 

[Hairyfool]

I would need to understand the DC to DC 12v charging better than I do but I think I would prefer to have an independent accessory battery to drive the inverter. That would take the MG5 battery out of the loop and leave it protected from discharge all together.

Not questioning your knowledge, just making a point.

Similarly I have been caravanning/motorhoming for many years and general practice is to leave the starter batteries out of use whenever possible.