Portable power station recommendations

General Drone Discussion
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Got decent charge rate off the new car charger, was happy with the speed it charged both phone and iPad :+1:.
Yet to try it on drone batteries, but first impressions great👍.

Ta Wayne

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You can get by on a Leoch 130Ah AGM (I use the SLCA version which is a bit pricier). It’s not ideal, you want more like 260Ah for use with a 1kw inverter (ideally you would probably go to 24V as well for efficiency), but two 130s are pretty heavy (32kg each for the SLCA version, 30kg for the regular AGM).

Unless you go Lithium, but then it gets pretty expensive.

If this is a car type installation, I would suggest you get a DC-DC charger, such as the Victron 30A and run it between the vehicle battery and leisure battery. If you are charging some massive DJI battery, then maybe leave the engine running while you run the inverter.

So stuff you need to know.

DoD on a Lead Acid Battery is 50%. Any more and you start to damage it.

Battery Power Capacity (Wh) = Battery Capacity (Ah) x Battery Voltage (V) x DOD%
Battery Running Time = ( Battery Power Capacity (Wh) / Inverter Power (W) ) x Inverter Efficiency %

So for the sake of example, using a 130Ah battery to run your 1100W inverter at 95% (check your documentation for the exact number) efficiency.

130x12x0.5 = 780Wh
780/1100x95 = 67.3 mins

So on a 130Ah, you can run the inverter for about an hour, then it will need to be recharged via Solar/VSR/DC-DC.

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65

Thanks Matt for a great explanation, fantastic👍

I’m good at a lot of things but electricals defo not especially the maths tekky part :rofl:.

At least you’ve given us an idea of what I can/can’t run :+1:.

The DC - DC charger you mentioned, would running it off one of the 12v sockets in the car then to the 130ah battery be sufficient, or doesn’t it work like that🤷‍♂️.

Or would I have to take a feed directly from my car battery, run it through the car to the charger in the boot?

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What are you running off the inverter to need 1100W?

I spent 3 months semi-off-grid and my 300W covered all my needs.

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Car wiring looms for accessories are never clever at anything above 5 amps (and often fused that that). One of the main reasons is they tend to go through multiple multi-pin connectors … that can get hot and melt the plastic.

I’d always provide a suitable dedicated direct wire - fused at each end - to the charger.

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This might sound weird, but haven’t an igloo yet. Just wanted someway of charging up batteries and anything else I may need to run for stopping out in the car.

At the same time I just thought the bigger the better, not that I need 1100w at the mo, but kind of future proof the situation. Hopefully after using the Rav4 for a couple of summers I’ll make the step up to a camper and it’ll come in useful then🤷‍♂️.

It’s proving more of a situation than I expected tbh😱

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Thanks again Dave👍

So I could do with an auto electrician then. :crazy_face:.

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So first thing. It all depends on how old your car is and whether it has regen braking and a part time alternator (older cars have an alternator that runs all the time). If it’s an older car then you can use a VSR (voltage sensitive relay), which will take whatever spare amps your alternator produces and dump them into the battery (only works on Lead Acid). If you have a newer car, then you need a DC-DC Charger (that has a capacitor in it, that can presumably buck boost the voltage up to something usable).

Also it won’t run through a socket. Depending on the version you have, it would either pull 30A or 18A (a typical 12V socket is max 15A and most 10A), so you would blow fuses, possibly melt wires and cause a fire, but the fuses would pop before that. :stuck_out_tongue:

So these are the Victron chargers:

VICTRON ENERGY ORION-TR SMART 12/12V 18A ISOLATED DC-DC CHARGER ORI121222120 8719076046066 | eBay - 18A £150
Victron Energy Orion Tr Smart 12/12-30A 360W Non-isolated DC-DC charger ORI12123 | eBay - 30A £200

If you want an alternative, Sterling do them too (and if you pick up one of their refurb’d models you can get a 30A for £130).

So if you have an older car without modern day faff like regen braking, then you can take the cheap option, the VSR. A full kit for a VSR with 5M of cable, is about £70 from SimplySplitCharge on Ebay.

This is what I use in my van. Basically when you start the engine and it detects the voltage going to your vehicle battery is over 13V it connects the two batteries together and allows the Leisure Battery to be charged from the alternator.

If you have a Lithium / LiFePO4 Leisure Battery, you have to use DC DC Charging.

An example wiring diagram. The one I use on my van. Ignore all the bits except for the AGM battery, distribution box, VSR and VB, plus the wire sizes and fuse sizes.

basic-elec-v1
basic-elec-v11711×800 139 KB

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71

Actually - the better question would have been - what are you needing to run at 245/250 volts (mains voltage) that needs 1,100W?

1,100W is a LOT. And needs everything associated to be that much more robust = that much more expensive.

As @PathfinderFPV has said (in similar words) - you need some serious batteries to supply a sustained almost 90 amps (at 12V).

This is the kind of thing you’d find in a serious motor-home with multiple batteries in parallel/series to take the load and mains sockets all around the place.

IMO.

Most things you want to charge can be recharged from a few lighter sockets at 12V connected to the Leisure battery. I only use the inverter for a few gadgets that are mains voltage only.

Another consideration - in a normal car (even if large … Shogun in my case then) that’s for normal day-to-day use most of the time - the Leisure battery is not something I want made so intrinsically part of the car that it can’t all be easily removed for normal life.

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Cheers Matt.

Yeh older car, Rav4 2007. Still running great and immaculate.

The whole idea behind this, is because of the age of the car. It’s way paid off, and want to run it hopefully for a couple of years.

I’m split to whether to get another newer SUV or camper, so in the couple of years left before the mortgage is paid, I thiught I’d try camping in the Rav. This power thing is beginning to get a bit more complicated than I would of liked :joy:.

The split charge relay you mentioned came up in conversation with someone else the other day👍. So now it kind of looks like it’s the way to go.

Thanks for all the links, much appreciated. I wouldn’t know where to bloody start​:man_shrugging::rofl:

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But you did know where to start … ask the question on GADC. :+1:

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TBH, that’s easy to overcome.

Whether you have a Charger or VSR, place a cut off / isolation switch or circuit breaker inline before it. On my VSR I put a switch on the negative cable. With a flick of the switch the VSR no longer works. On a Charger, put a 20A or 40A isolator or circuit breaker between it and the VB. Either way, isolate the circuit and remove the battery when you don’t need it.

Mine is a mini motorhome, so i have it permanently installed, but on a car you can make it more modular.

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@OzoneVibe yeh, everyones been so helpful as usual.

Thanks to everyone who chipped in👍.

I don’t know whether I’m more confused now having bought an Inverter :crazy_face::rofl:

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If all you’re really going to be doing is recharging a load of drone kit - and provided you have car/12V chargers for everything (or can obtain) - I can’t see a need for a 1,100W inverter.

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Off the top of my head, that would be a load cheaper than the additional cost of setting everything up to handle the 1,100W inverter.

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Just remember to use appropriate fuses and thick enough cables for the inverter. Fires are a real thing with inverters. When you size the cables, add 50%.

So some calculators.

Guessing you have a mains only camera drone battery charger and batteries that have extra electronics, that must be charged from AC. If it was LiPo’s or similar, then you can do them from DC pretty easily without an inverter.

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:point_up:

This! Fuses at each end of the car - easy to access.

Oh - and in any case - a small fire extinguisher in case … :laughing:

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Also - all cable end connections need to be really well made - and insulated.

A good crimping tool for the correct sized connectors is money well (I’d probably say “essentially”) spent.
Along with some good heat-shrink insulation to cover any exposed parts of the connectors, etc.

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A fire extinguisher rated for electrical fires and not powder, as it’s a major pain in the ass to clean up. CO2 is good, as are the water mist extinguishers. Powder is not fun to clean up. Also if you do use it, don’t inhale it. :wink:

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A mess that can be cleaned up is still WAY better than a mess that can’t ever be cleaned up. :stuck_out_tongue:

I had a car catch fire and destroy itself. It was a wiring fault … but nothing to do with me. Only owned it 1 month.