Building for off grid

[Johnnny]

Hi all looking for some advice. Got renault master conversion. Long story short I'm looking to replace split charge relay with B2B that's the first step. One I'm looking at is ctek d250se 20a as seems simple and basic. Next step is 200w solar and eventually lithium battery and inverter.
Question is will that b2b be suitable to let me do all that?
Usually use ehu but want to prepare for off grid and would only be for a couple days at a time
Any advice grateful
Thanks

 

[Lenny HB]

A 20 amp B2B is a bit on the low side if you are planning to change to Lithium a 45 amp one would be better providing your alternator can handle it, should be able to. 200 watts of solar probably OK if only going off grid for a couple of days and you can always add more.

 

[funflair]

Hi Johnny

Ooops Lenny pipped me to it but he has saved me typing, the trouble with only 20 amps from B2B would be when you had taken 100 amps from your batteries you would need a 5 hour drive to your next stop to be fully charged.

 

[Johnnny]

Thanks was hoping solar would remedy that and add to charge.
Only picked ctek d250se as been told straight swap over
My van is 2007 so not sure about alternator handling bigger amps
Wouldn't be using much winter so hoping solar suffice

 

[funflair]

Solar will help for sure but in the end it's all down to how you want to use your van and how much you want to change to accomadate the new tech, for example when we are away for a few days in the winter (no solar) we still use everything like kettle, toaster, coffee machine, microwave, etc etc all off the inverter so we can make a big hole in our Lithiums but travelling for a couple of hours will put close to 200ah back in, but if you don't take big chunks out you won't need to worry about putting lots back in.

^{_{Subscribers  do not see these advertisements}}

 

[Raul]

If you find the use in winter is not meeting your needs, you can always parallel another B2B.

 

[nicholsong]

If you find the use in winter is not meeting your needs, you can always parallel another B2B.

Then you really would need to look to upgrade the alternator.

If that were needed would be best to get bigger B2B now, upgrade alternator and wiring all in one. Job done.

 

[Jamesh]

Best not to use electric for heating.

Stick to gas / solid fuel.

Use electric for lights, electronics etc.

Microwave if you really have too.

Cheers James

 

[Johnnny]

Not looking to change alternator or upgrade wiring just wonder if this B2b be fine with 200w solar.
only looking at lithium for future as seems the way to go as think less maintenance. I haven’t got driveway so need to remove battery to charge hence the solar.hoping will charge battery when parked up

 

[Jamesh]

So long as your not looking to flt then it should be fine. Especially if your doing a decent amount if driving.

Cheers James

^{_{Subscribers  do not see these advertisements}}

 

[Johnnny]

When you say not looking to fit what do you mean?fit what?

 

[Tombola]

When you say not looking to fit what do you mean?fit what?

FLT

FLT - Free Loading Tosser. Someone who finds a nice little legal stopover somewhere and stops for weeks on end because he can. Showers rarely and collects crap which is stashed in black bin bags under the van. Gets everyone guessing where his toilet waste is being dumped resulting in barriers or...

www.motorhomefun.co.uk

FLT
when highlighted in bold, it leads to an explanation

 

[Johnnny]

No I'm not looking to do any of the above
For a start i wouldn't have the time off work to stay for weeks and spoil it for others
Only looking for advice on what to get for my purposes
Thanks

 

[Jamesh]

Btw I wasn't using FLT as meaning the above rather just Full timing....

Cheers James

 

[Johnnny]

Sorry I thought I read as long as I not looking to FIT as in install
I didn't understand FLT
No it just occasionally overnight if find somewhere nice not full time

^{_{Subscribers  do not see these advertisements}}

 

[Johnnny]

Hi and still looking at B2B .if I fit ctek d250se which is 20a and solar compatible for when I fit solar am I limited to solar mppt?does controller need to be below 20a or does it matter. Have my eye on 200w solar kit but before I buy ctek would rather know what it limits me with solar
Thanks for any help

 

[VXman]

To me this seems over the top for a 'couple' of days of grid. I've managed 2 days with one 95 AMH battery and no solar, 5 days with 2 batteries. I am in the process of getting a 175 watt solar. It will charge the leisure batteries only. This starter battery should be fine for that amount of time with no use. I'm hoping that'll do me 10 days for camping at the Le Mans 24 hour race in June.

My electric is phones, tablet, computer, Bluetooth speakers, power to run the gas water heater, water pump, led lights of an evening. That seems to use not much generally.

Of course if you want to use an inverter and have all the 'joys' of your electric kitchen at home that's another matter.

 

[Pugsy]

I'm hoping that'll do me 10 days for the Le Man 24 hour race in June.

why are you hoping it will last 10 days, ? if the race only lasts 24 hours .
sorry could not resist.

 

[Johnnny]

Thanks but yes would be using inverter for tv kettle and stuff. Heater is diesel night heater. Biggest problem is my fridge only electric not connected to gas
Basically I'm looking for way to keep battery charged without having to remove it as no driveway and would like the option of trying off grid for a night or two

 

[MisterB]

Thanks but yes would be using inverter for tv kettle and stuff. Heater is diesel night heater. Biggest problem is my fridge only electric not connected to gas
Basically I'm looking for way to keep battery charged without having to remove it as no driveway and would like the option of trying off grid for a night or two

Is it a compressor fridge? They seem to popular for off gridders ..

^{_{Subscribers  do not see these advertisements}}

 

[Johnnny]

Also don't mind going over the top with solar as only going to fit once. Don't want to buy b2b that no going to be good for solar and using inverter.
If I fit 20a b2b am I limited with amps on mppt controller?or does it matter?

 

[Johnnny]

Dometic fridge works off liesure battery and also connected starter battery for when driving
Not connected to gas
Was fitted like that when bought the van

 

[Two on Tour]

Also don't mind going over the top with solar as only going to fit once. Don't want to buy b2b that no going to be good for solar and using inverter.
If I fit 20a b2b am I limited with amps on mppt controller?or does it matter?

A B2B output should be going nowhere near your Mppt controller.

 

[Revolvor]

Hi and still looking at B2B .if I fit ctek d250se which is 20a and solar compatible for when I fit solar am I limited to solar mppt?does controller need to be below 20a or does it matter. Have my eye on 200w solar kit but before I buy ctek would rather know what it limits me with solar
Thanks for any help

I'm pretty sure that the CTEK D250 will handle 340w of solar. If you use that, you don't need an additional solar controller.

 

[Johnnny]

Now I'm confused. B2b from starter to liesure battery. Fine.
Then solar to liesure battery. Fine
Why is b2b solar compatible?
The kit I'm looking at includes mppt controller

^{_{Subscribers  do not see these advertisements}}

 

[Tombola]

Now I'm confused. B2b from starter to liesure battery. Fine.
Then solar to liesure battery. Fine
Why is b2b solar compatible?
The kit I'm looking at includes mppt controller

what do you mean, it is a combined MPPT and B2B yes they work fine, but no redundancy if one part of the unit breaks, it can mean you lose both.

 

[Two on Tour]

Just had a look back at your first post on the thread and see that your referring to the ctek d250se.

I have no experience of this unit other than to say that I steer clear of combined units.

 

[VXman]

why are you hoping it will last 10 days, ? if the race only lasts 24 hours .
sorry could not resist.

I've been to the race 4 times - each time in a car and tent over a short weekend due to work. Really looking forward to doing it properly now I'm retired and have the motorhome. Will immerse myself in everything from the practices, qualifying, driver parades in town and the race itself.

 

[Revolvor]

This is how the CTEK D250 is connected, to act as a B2B and MPPT Solar Controller.

 

[Johnnny]

Thanks for replies.have done bit homework and ctek d250 se is upgraded from ctek d250s.
without sounding stupid if I fit this ctek d250se which is 20a B2b what is my best option for buyin solar bearing in mind will be using inverter for some thing’s

^{_{Subscribers  do not see these advertisements}}