Yes - I think you're right, though the Renault Master which the campervan is based on does have a 150 amp alternator. Again my carefullness suggests one battery at a time! I will probably get the 600w inverter and see what power it pulls when charging one battery (via the van's NASA BM1 battery monitor), then maybe consider charging 2 at a time.

 

Kendalian

 

My camper van is also a Renault Master, and has the 150amp alternator, the problem with them is, when the alternator sees the engine battery reach 12.8 to13v, the regulator drops the charge back to a trickle 5 to 10 amps, and takes forever to charge them, the setup is designed to power everthing on a journey between campsites where you can hookup to mains, I seldom use campsites, so I have fitted a Sterling 120amp Batter to Battery charger, it draws power from the alternator and boosts it to 120amps, which charges my 550Amh batteries very quickly and the batteries run my 2KW pure sine wave inverter, the inverter also runs tv, sky box, toaster, microwave, laptop ect, solar power charging is fine when its sunny, but the Battery to Battery charger is a good backup and reliable, a 45 min drive will re-charge my batteries.

Your campervan must be set up different to mine. When the split charge kicks in the alternator 'sees' 300 amps of battery and continues to charge at a high level until al batteries are fully charged.

 

cheers

 

Kendalian

I want to charge a Bosch 400 battery from the batteries in the camper van

....

My question is, do I need to use a Pure Sine Wave inverter

 

Just giving this question a bump, as it doesn't seem there ever was a definitive answer.

I'm also interested whether the same also applies for the standard 4A Yamaha chargers as well.

Get yourself a lightweight generator. They're always useful. these ones are only about 9kg and they're very quiet:

 

http://www.ebay.co.uk/itm/Ex-Demo-Wolf-Power-Genie-WPG950-800w-2-6HP-Petrol-Inverter-Camping-Generator-/282593415907?hash=item41cbe152e3:g:12IAAOSw-FZXj3~x

I went for a 300w pure sine wave inverter in the end for £70 https://www.amazon.co.uk/dp/B00J68QL0K/ref=pe_385721_37986871_TE_item

When charging the battery it is taking 8.9 amps, with the leisure batteries sitting at 12.5v.

 

Cheers

 

Kendalian

I went for a 300w pure sine wave inverter in the end for £70 https://www.amazon.co.uk/dp/B00J68QL0K/ref=pe_385721_37986871_TE_item

When charging the battery it is taking 8.9 amps, with the leisure batteries sitting at 12.5v.

 

Cheers

 

Kendalian

That's 45Ah to charge your battery from flat (5 hours), which puts you on the limit of discharge for a 90Ah battery that's in good condition. You would then need to charge that leisure battery back up to full again before you could charge your bike. You can do it, but a deep discharge like that is not good for a leisure battery. It's no problem if you have your motor running while you do it, but then you might as well get a portable generator, which will probably use less fuel , and it has loads of other uses, like rescuing your motor-home when you run the cranking battery flat.

Get yourself a lightweight generator. They're always useful. these ones are only about 9kg and they're very quiet:

 

http://www.ebay.co.uk/itm/Ex-Demo-Wolf-Power-Genie-WPG950-800w-2-6HP-Petrol-Inverter-Camping-Generator-/282593415907?hash=item41cbe152e3:g:12IAAOSw-FZXj3~x

 

Yes, I can see a small generator like that could be a sensible option in many scenarios.

However I already have a couple of (non sine) inverters, and if I could use those to charge a Bosch/Yamaha battery using the existing 4A chargers while I'm driving from place to place, that would be ideal. And I don't particularly fancy the idea of having a petrol generator running in the back of the RV on a long drive .....

Well, I have 220 ah of leisure battery capacity; 200 w of solar panels on the roof (charges at over 10ah on a reasonable day); I tend to tour around quite a bit and the alternator is 150 amp; worst case I will pay for electric hook up - in summary, I'm not worried about depleting batteries.

 

I wouldn't entertain a generator, anti-social monsters - you are hated if you use them on sites!

 

Cheers

 

Kendalian

It's not quite answering the question but many of us living on narrowboats also have e bikes, often folding ones. My charging is always done with the boat engine running usually as we travel along. My set up is fairly typical. There are four 110 a/h leisure batteries charged by the 70amp alternator. In addition there are two 100w solar panels feeding into the batteries via a mppt solar inverter. This often shows 10amps in the sun but they do little more than trickle charge the batteries in winter.

The boat has a Vetus 1000w inverter to provide 240v power which we use for charging the Volt 12ah bike battery, my wife's hair straighteners, an electric drill occaisionaly, small vacuum etc but not the tv, lights or fridge. We are a low use 12v system on the whole.

We have no problems keeping the bikes battery charged up. Mind you it's only used two or three times a week. I get normally a comfortable thirty mile or so range.

I thought we were talking about a camper van parked up off site somewhere. Surely, if you're on site, you can charge from the mains. why would you want to use an inverter?

On the continent they charge extra for electricity - about 4 euros/night, so when converting the van I took the decision to fit solar panels to avoid this cost and also to allow for 'wild camping' when I want to. A 3 week holiday could easily incur charges for electricity of 80 euros, so solar panels are very cost effective.

 

Different in this country - most site charges include electric whether you use it or not. We prefer to holiday on the continent for the weather.

 

Cheers

 

Kendalian

On the continent they charge extra for electricity - about 4 euros/night, so when converting the van I took the decision to fit solar panels to avoid this cost and also to allow for 'wild camping' when I want to. A 3 week holiday could easily incur charges for electricity of 80 euros, so solar panels are very cost effective.

 

Different in this country - most site charges include electric whether you use it or not. We prefer to holiday on the continent for the weather.

 

Cheers

 

Kendalian

Each to their own, but I used to find the cost of the electrical connection very reasonable in my caravaning days. It meant you could boil kettles in a quarter the time of gas, run a small TV , and roast a chicken, using those cheap tabletop ovens, or do a stew on an electric skillet. .. pre microwave days. My recall is that there was typically 10amps available ample.

 

Unless you were only using the solar panels for lighting ...

Hi Danidl - yes, things have moved on from when I used to caravan. Electricity price on site has taken a considerable hike in recent years while the price of a solar system has dramatically reduced. Opting to install the solar means I can use basic sites or no site at all. You often find the quieter pitches on sites are those that don't have electric hook up available so it is a win win for me.

 

Cheers

 

Kendalian

I have to idle my RV when charging my bikes, or I have the same problem.

 

If you have a 100 Ah 12V RV battery, that's ~1200 Wh. Your e-bike battery holds ~700 Wh. So, it makes sense that, with losses, charging up the bike can almost completely kill the RV battery. Even with more efficient gear, you will get closer to ideal, but the best case you still drain most of the RV battery. I use an 8 Amp charger, on an inverter of course, so I minimize the time required. But I still need to idle a couple of hours for a full charge. Some gas wasted, but quiet, at least.

 

The main alternative to that, and a more efficient one but not worth it to me, would be to use a truck generator. But, we do need to make the power somehow. For you, if you don't want to run/drive the RV to charge, a small generator for charging would probably do it faster and has other benefits. I'd probably do that if I were you.

 

If you were to spend $900 for more battery, would that be better spent on more e-bike batteries, not another RV battery? Probably enough for weekend trips. But if you need more than a couple of days riding energy, that's not a solution.

Can't answer the OP question directly but once when camping plugged in my mobile phone to the car foggy lighter to charge overnight. Next day phone was fully charged but car wouldn't start as it had a flat battery.

 

No phone reception so couldn't call AA. Ended up connecting phone to car battery directly using jump leads to start the car. (Well OK no I didn't but I did wonder what might happen if I tried! Jump started using another car.)