How many Power station Wh = 2 hours on a generator?

[Vanman]

I'm hoping that anyone can give me a clue here ...

When away at bike race meetings etc. I normally have to top up the batteries from the 2nd night onwards with about 2 hours of generator per night. I'm thinking of replacing the generator with a Power station but haven't a clue as to what size I would need to cover x3 nights of 2 hours. I'm guessing that the EHU set up only takes power at the rate that the batteries (2x 110) take charge, but that's about as far as I've got ...

I've been looking at the Anker 256 Wh or 512 Wh battery packs

Thanks!

 

[Ian_H]

I'm no expert but
You shouldn't be running the batteries below 50% so charge from 50% for both is 110ah. Multiply by 14V = 1540wh. So you would need a bigger power station. And that would be one day, you would need to recharge the power station or have one twice as big for the next day......
Edit- it takes you 2 days to drain batteries so I guess you could halve these numbers, but same result- bigger power station!

 

[Cush]

My advice, from experience, is that if you have the space and don’t need to use the genny anywhere else, then add a bigger battery / lithium. A decent sized power station (2000 wh) is >£1.2k. Just my experience. My 767 is about 160 ah.

 

[The Wino]

I'm hoping that anyone can give me a clue here ...

When away at bike race meetings etc. I normally have to top up the batteries from the 2nd night onwards with about 2 hours of generator per night. I'm thinking of replacing the generator with a Power station but haven't a clue as to what size I would need to cover x3 nights of 2 hours. I'm guessing that the EHU set up only takes power at the rate that the batteries (2x 110) take charge, but that's about as far as I've got ...

I've been looking at the Anker 256 Wh or 512 Wh battery packs

Thanks!

I think it's easier to look at the discharge rates for the existing batteries than look at the charge going in. For example if they are going from 80% to 60% you are using 20%of 220ah so 44ah. Your power bank would need 3 times that at least. The good thing with a power bank is you can recharge them relatively quickly assuming some mains power is available or you could have separate solar. If everyone else is also using a generator it could be you're better to carry on with that as you wouldn't annoy anyone

 

[Vanman]

My advice, from experience, is that if you have the space and don’t need to use the genny anywhere else, then add a bigger battery / lithium. A decent sized power station (2000 wh) is >£1.2k. Just my experience. My 767 is about 160 ah.

Thanks, I only have a small van with no more room in the battery location. Changing the whole system to Lithium is probably never likely to happen so I'm looking at something than can live most of the time in the 'garage'.

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[Vanman]

I think it's easier to look at the discharge rates for the existing batteries than look at the charge going in. For example if they are going from 80% to 60% you are using 20%of 220ah so 44ah. Your power bank would need 3 times that at least. The good thing with a power bank is you can recharge them relatively quickly assuming some mains power is available or you could have separate solar. If everyone else is also using a generator it could be you're better to carry on with that as you wouldn't annoy anyone

Thanks for taking time to post that, it’s made me think. Part of my problem is the Van control panel for the batteries, it only has x4 lights for 13.5v (charging) 12.7v (full?) 12.2v (needy) or 11.0v (in trouble) so as soon as it drops below 12.7v it shows 12.2v even though it could be 12.6v really.

I just checked my batteries and they are 2x95Ah AGM – 190Ah

So if I assume that my batteries are going from 100% to 75% most days off EHU that’s about 50Ah used. These Power stations seem to be sold in Wh and if Amps x Volts = Watts the 50Ah x 12v = 600Wh. If those figures a anywhere near then I might be able to get by on the 512Wh model if I keep my beer fridge turned to low, and to off if necessary.

I’m planning a trip to Le Mans next year and I’m a bit wary of taking the generator and spare petrol to the EU, through the tunnel etc. I do have a bit of Solar so maybe being in France will help too! Do these figures 'add up'?

 

[Landy Andy]

I’m surprised you only get two days from two batteries. We have two batteries, there are two of us, 7.5m van, plenty of lights in it. No solar, no B2B, and easily get four days.

Possibly asked above, but how old are your batteries? Ours are 4-5 years old.

 

[autorouter]

So if I assume that my batteries are going from 100% to 75% most days off EHU that’s about 50Ah used. These Power stations seem to be sold in Wh and if Amps x Volts = Watts the 50Ah x 12v = 600Wh. If those figures a anywhere near then I might be able to get by on the 512Wh model if I keep my beer fridge turned to low, and to off if necessary.

I’m planning a trip to Le Mans next year and I’m a bit wary of taking the generator and spare petrol to the EU, through the tunnel etc. I do have a bit of Solar so maybe being in France will help too! Do these figures 'add up'?

More or less, yes. You need to account for lead-acid charging being no more than about 80% efficient, so if you use 50Ah you'd need to put in at least 60Ah to get another 50Ah out. Lithiums are much better, over 95% efficient generally.

Another possibility is, usually a 1000W generator is only running for charging the battery, so if it's a 30A charger that's 30 x 12 = 360W. There's plenty of power available to charge say a Power Station at the same time. So if you're meeting friends there you could get by with one generator charging one set of batteries and a power bank. Or even two or three power banks

 

[Vanman]

I’m surprised you only get two days from two batteries. We have two batteries, there are two of us, 7.5m van, plenty of lights in it. No solar, no B2B, and easily get four days.

Possibly asked above, but how old are your batteries? Ours are 4-5 years old.

I have an electric only fridge that gobbbles up the power, and as explained above I tend to start panicing when the 12.7v light goes out

 

[Captain Yoghurtpot]

I’m surprised you only get two days from two batteries. We have two batteries, there are two of us, 7.5m van, plenty of lights in it. No solar, no B2B, and easily get four days.

Possibly asked above, but how old are your batteries? Ours are 4-5 years old.

But what size batteries?
And what type?
That might help in the discussion.

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[autorouter]

I’m planning a trip to Le Mans next year and I’m a bit wary of taking the generator and spare petrol to the EU, through the tunnel etc.

I don't particularly like generators but I don't see a problem with that. Lots of people, including myself, carry a small scooter/moped/motorbike, with a small can of petrol in case it runs out.

 

[Landy Andy]

But what size batteries?
And what type?
That might help in the discussion.

I’m sorry I wasn’t helping the discussion. My setup is the same as the OP.

 

[StillGoing]

If you’re going to Le Mans for the racing, I don’t think anyone will hear your generator above the noise of the racing, fun fairs and other people’s generators!

 

[Manic]

I would stick with generator, you can always get petrol but if your power stations run out it would be harder to refuel then.

 

[Cush]

Thanks, I only have a small van with no more room in the battery location. Changing the whole system to Lithium is probably never likely to happen so I'm looking at something than can live most of the time in the 'garage'.

Understood. A decent power bank with solar panels (you can buy cheaper ones at the correct spec than same brand ones) may be just the job. My bank gives me additional 150ah on 12 v which would be a considerable increase on your current capacity, if your batteries are in good condition. Good sun could recharge a power bank at about 10 amps or more during sunshine. Also handy to use in the shed and house. To run the fridge you could use a power bank to mimic ehu but not the most efficient.

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[Raul]

Forget about batteries, power banks etc. for a moment. Pick up a killawatt meter and plug your van in it, then plug that in the ehu.
It will monitor what you use per day week etc.
At the end of your stay have a look how many kwh you used from ehu to sustain your needs. After that, chose your power bank/batteries large enough to cover the consumption recorded.
Something like this will do the job nicely.

Pardon our interruption...

 

[Cush]

it only has x4 lights for 13.5v (charging) 12.7v (full?) 12.2v (needy) or 11.0v (in trouble) so as soon as it drops below 12.7v it shows 12.2v even though it could be 12.6v really.

Just a thought. A cost effective option may be to consider a shunt so that you have clarity around the SoC of the batteries that you have then maybe some portable panels to boost on a sunny day?