#145971  by Secala
 Sat Nov 03, 2018 6:46 am
Hi All
I have read much of the very good info here, to the point that I'm relatively comfortable that my question is covered. With no electrical credentials on my part, making assumptions are fraught ........
Am just wanting to check that my current 240v needs would be met by the following setup.
Current 240v needs: laptop (max 85w draw). Probably future e-bike charge for wife ( they don't make e-bikes for men, do they? :Y :Y )
Motorhome electrical specs: 160a/h house battery, 1000w inverter, 150w solar

We have other iPad and phone devices but expect these will charge direct off 12v usb.

I can upgrade to double solar (300w); 2000w inverter and appropriate battery upgrade for about $3,500 - $4,000; but for my needs, this looks an overkill.

Your thoughts?
Are there any obvious 240v that I could/should be considering. (Hairdryer, for me :lol: )
 #145974  by vansvilla
 Sat Nov 03, 2018 8:00 am
Well you can never go wrong with increasing your solar. So I would do that upgrade.
Your existing 240V needs would be quite comfortably handled by your existing inverter or even a smaller one. We have a 350watt PSW that charges the laptop, E bikes as well as running the tv and sat box. E bikes only charged during the day.
Unless of course the Hair drier changes from a nice to have to a must have!
Do you charge when driving?
The other question that gets asked is how many seasons do you intend using the vehicle but given the weather patterns now the seasons are in name only : :-T
 #145975  by mattn
 Sat Nov 03, 2018 8:46 am
I hope the $3500-$4k includes 200AH of Lithium batteries, shop around to make sure you are not being ripped off.

AA Solar prices - Panels are about $1 a watt, controller about half that, batteries (lead) $300/100AH (Lithium 4 times that), plus installation bits - wire, mounts etc. Adding 150W and 150A/H should cost no more than $500 for the battery and $500 for the solar plus a bit of labour (a couple of hours max). Even ripping out everything you have and staring again from scratch should cost less than $2K.

Don't expect much E-Bike riding from 150W solar. Presume you have a 300W motor running at half power, an hour of full sun is an hour of riding, but you also have to run the house off that.

As for inverters - size them for what you need. 1000W won't run a hair dryer on high heat, coffee machines etc. You may be able to run a toaster. Step up to 2000W only if you have a need for it, but be very careful - 2000W for 5 minutes takes over an hour of full sun to recover with 150W of solar.
 #145979  by Growlerbearnz
 Sat Nov 03, 2018 9:38 am
I agree with the above advice. I would add the second 150W solar panel and see how you go. (Our wee caravan has 200W of solar and 120Ah battery, and things get a bit fraught after 3 days of rain.)
 #146035  by Skiwi
 Mon Nov 05, 2018 7:54 am
You can see the power specs we have (which would be overkill in your case) in my signature and for us it meets our needs and wants beautifully. - (Fridge, tv, microwave, toaster, oven, laptops, ipads, etc etc etc etc)

The upgrades you suggest seem reasonable for your situation.

Some things to keep in mind:
More solar is always good, it not only means you recharge quicker on sunny days, but also helps maintain on overcast days.
Unless you increase your long draw battery load significantly (solar fridge as an example) I think 320ah batteries would be sufficient (this gives a real world draw down of about 160ah).
Short but intense draw-downs (hair-dryer, toaster etc) are unlikely to as much impact on your batteries as long slow drains, but will require a beefy (2kw+) inverter.
Check your quoted upgrade includes a pure sine wave inverter and a MPPT solar controller as modified sine wave and PWM solar controllers are inferior and should be avoided if possible.

 #146052  by Neddy
 Mon Nov 05, 2018 3:58 pm
Secala, your 230v needs are relatively modest and should be easy enough to meet so I would advise you to initially concentrate on your overall 12 volt requirements. I guess that these are to some extent unknown at this stage so I think you should be in no hurry to replace your House battery just yet. It is not impossible that battery capacity of 160Ah may prove to be sufficient for your needs. A good initial investment for you would be to fit a battery monitor and see exactly what your electrical consumption is.

You have minimal solar power capacity at the moment and this needs to be increased, maybe by quite a bit. Rather than decide on some arbitrary additional amount, I suggest you measure up your RV roof and see just how much spare space you have got for more solar panels. For most of us this is the main constraint that limits the amount of solar power we are able to fit.

By way of example, our new RV had a nice clear flat roof area measuring 2000mm x 1650mm. What to do? Answer - fit as much solar capacity as possible. This turned out to be two 280 watt panels costing $265 each giving us 560 watts of solar power for just $530 plus a few dollars for aluminium angle and cables. Even adding a suitable controller only brought the total to $800 or so. Solar power is cheap.

To me, your proposed $3,500 - $4,000 upgrade to gain just 150 watts of solar power looks to be very poor value.

 #146056  by Secala
 Tue Nov 06, 2018 4:51 am
Hi All
Thanks for your detailed replies. Message received. Load up on solar and shop around. Very much appreciated. Cheers Brent
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