1963 vintage DIY bus conversion. Mini appartment on wheels with camping, adventure and offgrid capabilities. Topic- Solar energy system.


New Member
Nov 26, 2022
New forum member, first posting. Im not getting into how many hours i have spent reading and serching the forum, but thank you all for making a great forum and sharing your knowledge , experiances humor and enthusiasm for solar enegi DIY, also for your patience... Pleace take into consideration that im wrighting form Norway, i did not pay much attention in school and i didnt really get along with my english teacher so im sort of winging my spelling.

So anyways, i got a bus...

1963 Volvo B615-05 built for the Norweigan armed forces, south Batallion ,infantry , TrenTroop. In service from 1963 to 1983. Its only got 38.000 km (26.000 miles) on it but the new car smell has faded somewhat, also the paint.. I bought it last year, for a chokolate bar.. The man who got it from the army passed away in the early nineties so the bus sat in the back yard for thirtee years when i found it as it appeares in my profile picture. Focus this last year has been to get it roadworthy and approved for licenceplates. Volvo truck center approved the bus (with flynig colours) in july (and all their mecanics came and checked it out). Its got its licenceplates , and i took it over the mountain for a test trip. it got its driver seat, one original army double seat, 6 new tires, other than that its totally stripped out and ready to be rebulit and regain its dignity, howewer ist winter here and temperatures are low, more tempting to make plans than execute for now.

This is the long story, il do the short story in the end of the post so you migth just skip this part but i can`t find a way to lay out the backgrond wihtout elaborating to some extent. I sold my cabin cruiser (boat) to get a bigger one, then i met a woman and she got her self a dog, then i sold my house and we got a house in a homeowner assosiation, then i got screwed, then there were just me and the dog, then i got bored and bougth a bus. so mow i have a big bus and a small boat. The bus must take the role of the boat and offer all comforts, hopefully it wil be a low budget project and im prepared for the long haul and accsept that it will take time. Fun fact, i served in the army, same base where the bus was in use but 10 years later. The bus got a bullit hole, i have not.


Use as an mini appartment when wisiting my grandaugther (2yrs)on extended visits in a city inviroment, no guestroom, no parking. City RV site with shore power in walking distance. 8 hour drive over Dovre ( in the white part of the map of Norway) mountain thru brethtaking nature and some roads that make the hairs on your arms rise, check out Trolls ladder if you dare https://www.nasjonaleturistveger.no/no/turistvegene/geiranger-trollstigen/

For offgrid camping, roadtrips and festivals, and who knows, world travel?

For lending to my sisters, my son and he`s inlaw family for wacation and family trips. this means most things shuld be automated or at least intuitive to use.

Season: I got the 3peak mountain snowflake tires as i will meet winter conditions while on the road, however this bus has sat for 30 years and i imagine it will be winterized and spend the coldest season parked and totally shut down and it should be fine with that. winter use demands antfreeze in toilet/ blackwater tank and carry on freshwater but i consider wintercamping to be unlightly.

Some facts
Original steel bus frame B615, Aluminum chassis, corrotion insulated mounts to steel frame. fiberglass soft corners and roof ends.
24 volt system. 2 donated sligtly used and sligtly mismatched sealed led acid 120+135 AH 12v batteries in 24v configuration, charger relay, dynamo and starter, blink relay and lights. dead simple. air brakes-door-and window wipers. one layer glass windows exept front windows. mecanic hand brake. no servo
3-5 cm wall insulation , guesstimate same in roof, uninsulated floor plywood. steel floor in front, also not insulated.
Steel roof brackets tru aluminium roof frame for outside roof mount, about 55cm (21 inch) longside 143cm (56,7 inch)appart acoss. covers 4 meters of the lenght, possible to add more brackets and add 1,1 meter. roof space max 5,1X1,43 M or 4X1,43M
total length 10,15M with 2,3M weight now 6200 kg, max 7500kr on the road

Propane coocking, propane on demand hotwater. 24V 60W waterpump 5 l/min should keep showers few and short. marine toilet undecided on 24V or manual, leaning towards manual as 24v make noise. undiceded on fridge, propane vs 230V -any advice? Heating - Primus propane water heater 12V 2A. Underfloor/in floor / inwall watercarried heating 24V circulation pump. Wood stowe if i can find a way, not sure this is legal. 5KW diesel heater 24V china model. 230V minisplit ac/heatpump ac 900W/heat 820W. Exessive use of TV, laptop computer, ipad and so on. there will also be Thread, LoRa IOT and lots of fun "Home"automation and remotly controlled devices.
power consumption isnt really an issue, on this setup i can conserve energy when i need, and enjoy all comforts when plugged in to shore power.

Im keeping all windows as is and im aming for a 60-70th look on interior and exterior, I realy want to max out on solar panels to extend freedom to stay where ever i like but id like to keep the panels witin the roofmounts if i can to minimise their apperance. I will try to insulate better wehere i can but it will get really hot in the summer so i will need an hour or two of ac in the hottest periods( when its sunny) In spring and autum the evenings and mornings might be cold and i will have to put in some effort to keep comfortable.

Diesel heated powerwasher removed most of the paint, it was white on blue, back in its haydays it had its army colour ofcource. It will get better!

Start reading here:

I have 10A and 16A dc brakers and this AIO all in one unit
MPPT hybrid solar inverter charger SMH3K on label:
operating temperature range 0-55 C
Inverter mode rated power 3000VA2400W
DC Input 100A AC Output 230V/AC 50hz 13A 1C
AC Charger mode : AC Input 230V/AC 50hz 17,7A 1c`
DC output 27V DC 30/20A
Solar charger mode: Rated power 1000W
maual states max current 40A Max PV array open circut current 102 A
MPPT operating voltage range 30- 80V system voltage 24V max solar voltage (VOC) 102V DC

Further limitations is roof space for pannels. ideally around 1430 mm X 4000-5000 mm
shading: shading will defnetly be an issue. Irradiance: flat surface mounted jan- ,37 feb ,1,09 mar 2,29 apr 3,57
may5,36 jun 5,6 jul 5,58 aug 4,24 sep 2,71 oct 1,28 nov ,54 des ,24 coldest average temp: febuary 4c , coldest average recorded feb 1970 -11C id say -20c would be the extreeme, i remember - 16c. .

i have looked hard at locally avaiable solar panels, even used ones, but im struggeling. small 12 to 20 V panels are way overpriced, and hard to configure to comply and meet all AIO demands without being seriously effected by shading. panels around 30-V will in most cases not be ideal either. I think i need to up the volage and go paralell, these is all iwe found:

Operating ParametersSTC
Maximum system voltage 1500V DC
Operating Temperature -40 ~ +85 C
Maximum series fuse rating 20A
Snow load, frontside/Wind load, backside 5400Pa/2400Pa
Nominal operating cell temperature 45 C 2 C
Application level Class A

Module Type DHT-M60X10/FS
Maximum Power (Pmax/W) 460
Open-circuit Voltage (Voc/V) 62,4
Maximum Power Voltage (Vmp/V) 52,8
Short-circuit Current (Isc/A) 9,31
Maximum Power Current (Imp/A) 8,71
Module Efficiency (%) 21,32

NOCT—Electrical Characteristics
Maximum Power (Pmax/W) 346
Open-circuit Voltage (Voc/V) 59,1
Maximum Power Voltage (Vmp/V) 50
Short-circuit Current (Isc/A) 7,51
Maximum Power Current (Imp/A) 6,92

Cabel 4.0mm2, 300/400mm in length,
No.of Cells 180 (6×30)
Glass 3.2mm High Transmission, Antireflection Coating
Junction box IP68, 3 Bypass Diodes
Connector MC4 Compatible
Weight 23.5kg
Cells Type Mono 182×60.7mm
Dimension (L×W×T) 1903×1134×32mm

In real life two panels maybe dissapointing?
question, manual states 40A max and working voltage range 30-80 volts , 102 voc max and rated out power 24V, what maybe many AIO newbies wonder, especially me is: are the 40A max current calculated/limited at the rated outpower of the inverter charger at 24 V or the pv array voltage?
any tips and advice apretiated!


edit1. I found this forum serching for reliable source for lfp cells, i forgot to mention this, i had my mind on a huge 304AH 24V pack. My plan is to disconnect for storage when cold/freezing may accure
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Cool looking bus and project. Sorry cant be much help about solar just learning myself.