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Camper Electrics
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20-12-2016 12:56am#1Hi all,
I'm in the design stage of a campervan conversion and just starting to plan electrics. I've pretty much finalized what I need to include and I plan to mostly wild camp so will be dependent on alternator and solar charging. 240 hookup isn't a must but figuring I'd include so all bases are covered.
So, now I'm looking for any advice I can get and try to figure out the best way/how to wire it up, what to avoid etc.
The image includes what I think I need as a starting place to plan the wiring so hoping someone can give me some advice, pointers etc. to get started.
Thanks for any help you can give.
Cheers,
Tom
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Hi Tom,
Just when I thought all the campers and caravans were snoozing comes the mother of all electrical questions! Gorsh...I better have a lie down before I get too excited.
I must commend you on a practical amount of solar panel. I would call that an ample amount for wild camping...at least to start off with....
Questions:
Logistics:- What's the budget?
- Have you much electrickery experience?
- What is your target maximum range without plugging in? Never is the most expensive option.
- What appliances do you want to run? What are their ratings in watts? What is your average daily load in Wh, kWh or Ah?
- How much down time will the rig have between trips?
Charging:- Solar PV...correct!
- What size is your alternator? Do you want a second one (cos two are 4 to 8 times better than a split charge system).
- Split Charge Fusing, Cable and Contactor.
- Split charge control trigger? Automatic/Manual/Intelligent/All of the above?
- I recommend facilitating a mains input for several reasons; It doesn't cost that much extra to make the van mains compatible, you need it for servicing and redundancy, conventional power is the cheapest source...why use expensive batteries when mains is available? ...maintenance charging, consistent inclement weather, free power outlets (not in, can't win).
I being the uncompromising must have redundancy must be maximum efficient so-an-so build dual source powered systems so appliances can discriminate between available power sources with priority to the most abundant. Others keep it simple and design a 12volt system and then spec a massive charger that can charge while running all the usual loads...this puts a single point of inconvenience into the rig. Others again design everything for mains and use a lossy inverter to run loads away from conventional power, this puts a single point of failure into the rig and is generally bad for wild camping as you quite often lose more power to the inverter than the appliance.
Where woz I...ah mains charger....er I recommend having one but never met a one I liked. They're generally all too expensive and not very good. I use hybrid solar controllers instead fed with current limited power supplies...these are the best solution I've found and probably cheapest for their rating and functionality when you run solar also.
Don't depend on alternator charging it never meets peoples expectations. It's a contributor not a contender.
Distribution:
Two areas can be side by side but try to keep mixing voltages to a minimum.
One area for Mains one for 12V (or 24v?)
Mains Distribution (suggestions):- Sub-Main Distribution box with circuit breakers.
- Mains (Only...do not put on inverter radial) Charger
- Inverter
- Mains/Inverter Changeover
- Mains/Inverter Outlet Sockets. How many? Whereabouts? Complete with integrated USBs?
- Lighting Transformer & solid state relay
Low Voltage Distribution (suggestions):
- Master Fuse
- Distribution Bus
- Inverter Fuse
- Appliance fuses
- DC miniature circuit breakers
- Lighting Switches (dimmable?)
- Striplight Driver
- Striplight Controller
- Charger Voltage Sense conductors.
- High Current low voltage outlets (laptops, power tools)
- Cig. lighter low voltage low current outlets.
- 12V -> 5V USB Sockets
- What size capacity battery do you need?
- What physical size battery can you afford?
- What battery type do you prefer? Flooded Lead Acid(yes), Sealed LA(erm...), AGM LA(no), Gel LA(no³) or Lithium Ion (brave).
- What sortov lifespan do you need from them.
- How often do you plan to use them?
- Why is it everybody thinks this isn't necessary?
- Fans: easy (fuse -> switch -> appliance).
- Igniters: easy.
- Water pumps: easy.
- Electric flush: easy. Gravity is reliable.
- Water sensor: buy one, make one or make the tank translucent and just look at it.
- Waste water: same for above except eye-balling isn't the best option. If it's the same size as the fresh water then use the inverse of the fresh water level reading, if it's half size then inverse by 2. You'd be amazed how little is drank/unaccounted.
- LPG level sensor...much cheaper/easier/more practical options, comes with a kit if you prefer to pursue the LPG tank.
- Why do you need an inverter?
- Why do you need a true sine inverter?
- Compressor fridge or abortion fridge?
- Light switches depends on what you want one light one switch = easy. One light, two switches, two power sources self-prioritising which source...is not that complicated but takes a while how to get your head around the best way to implement it.
Run the cables first, conduit is recommended but I never bothered, I might if I was to do it again. Label both ends of everything and leave 1.5m excess after where you think you want the cable to land, you can trim it when you install it.
Future proof it with and audio, data, power cable etc... If you are thinking of getting things you can't afford yet install the cables early when it's easy so they're there when you can.
Mains ought to be done by a sparks on stranded flex. Low voltage would best be tackled by a marine electrician on red and yellow or red and black conductor sets (in my experience mechanics, electricians and some auto-electricians can't wire low voltage...they can do it safely but the system rarely works to it's potential afterwards).
I did all mine myself and have it acceptably right-ish enough for me after umpteen retrofits. I'd do it all differently if I started again.That's just the mains, switches and some low voltage down-lighter sets...
85m of 3 x 1.5mm² flex.
The serious DC stuff happened years later.0 -
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Hi Tom,
Mod Note: I moved this to a new thread because I get the sense you are no tyre kicker and think this thread has merit in it's own right. Hope you don't mind.Really appreciate the help in starting to figure out this 'little' project.
No worries if I have the time I'm happy to help.What's the budget?
---I'm expecting it's going to be 2-3K with panels and batteries.
I think that's realistic...wait is that for just the electrics or the entire conversion?---I don't have any real electrical experience other than round the house maintenance type stuff. I'm ok doing diy and try to do as much as possible myself which is my aim with this job too.
Fair play that's all you need.---I'd like to shoot for 1 week and 2 weeks if any way reasonable.
Yurp. It's recommended you get a full charge at least once every week. I run up to 3 in the Winters with no deterioration. Myth busted as far as I'm concerned but I aim for 1 week or less deep cycles where possible.What is your target maximum range without plugging in?
---I’ve included a list of apps that will be used (at different stages). I’ve gone overkill on max usage times to ensure I have enough power stored. It’s coming in at 120ah so with 50% usage of batteries I guess I’m looking at minimum 240ah’s. Oooh good on you, data..that helps immensely
- What's column G?
- You've calculated you need 120Ah per day and want to run up to 2 weeks? Is this correct?
- Your fridge only runs 8 hours a day not 24?
- It's unlikely you'll use all the lights at the same time.
- No mains/inverter sockets?
- Your leds are 2.8w per meter?! How many leds per meter? What colour temperature? Lumen per watt...sounds way too low, is what I'm getting at.
- Everything you have spec-ed as 240V can run off the 12v system with the right converters.
- Is the laptop a Mac or PC? This might be an issue.
- Add 20% to the power consumption figures for the inverter efficiency and also note it's quiescent power consumption. Add this to final figure or lose the inverter. It's just a very sophisticated and expensive, electric heater for those intents and purposes.
---In terms of batteries is there an advantage/disadvantage to using 6v in series instead of 12v? The 6v’s seem to have way deeper charge capacity. I’ve seen some mention that if a battery fails you need to replace both (in the case 2 x 6v if one of the 6v’s acts up). I make’s sense I guess but wondering if you’ve any advice there.
Batteries don't die they are killed by owners unless you are very unlucky and it's a bad batch which you'll know before your warranty runs out. If one battery fails in a bank then you're better off replacing both. They live and die together, new batteries do not pair well with old. One new battery + one old battery in a bank = 2 old batteries.
Nearly every 12volt battery you find is a car starter battery with a label that says leisure on it designed for a market that uses them 12 times a year and will give you 300 cycles at 50% discharge until they are rated dead. Manufacturers know it's a safe bet sell junk within the leisure market.
6V are industrial they weigh more for their rating and they deliver >25% more power over their lifetime (compared to 12volt deep cycle), they are cheaper per extracted watt hour by far, they are true deep cycle. There are no 6v starting applications of that scale to fudge the boundaries with. Industrial users use their batteries 200 days a year and would make a manufacturer eat them if they fail every second year.
Further to this series is better. You can rotate the cells so as they age the weakest live in the middle and the strongest outside they will always balance when you do this. If a cell dies in a series config. then you drop 2.2V. this is obvious you have a problem that needs resolution. If you lose a cell in a parallel bank of 2 batteries the bank drops 1.1V you'd hope this is obvious...as you add more parallel batteries the discrepancy reduces. It's more difficult wire series batteries incorrectly.How much down time will the rig have between trips?
---Probably 1 - 2 months max between trips
Happy days. You don't need to mains float charge, PV can do it.What size is your alternator? Do you want a second one (cos two are 4 to 8 times better than a split charge system).
---Not sure about alternator size. Van is a 2008 Ducato Maxi.
Answers ona postcard...Split Charge
---Now this is where I start to get lost! I'm looking to charge the leisures off alternator when I drive and then have the solar kick in when stationary to maintain the charge. Split charger deals with this and protecting starter battery from draining and controlling other charge sources right?
Yes but how well it does that is all about how you wire it. You can leave PV connected while driving, it only makes a difference if the circuit is wired badly. I drove 30 miles on solar powered marker lights and wipers once when my alternator brushes failed.---I'd like to install an intelligent system as opposed to manual switching etc.
Probably wise. How about an intelligent system with the option of manual switching?
Better looking at it than for it. It's vital when if you do something stupid like leave a light on in storage.will include a mains connection especially for maintenance charging.--- OK, certainly don’t like the idea of depending on a single source so that is why I want to have top-up charging from alternator while driving, solar panels and mains hook-up with a control system to prioritise as necessary. Is that what you mean by having redundancy?
Kindof. Redundancy is that when things fail they fail isolated. One component does not take out a system. For instance I would install 12V lighting if I had to remove the battery for servicing then I can operate the same lights from mains via a power supply. If the changeover relay between 12v and mains failed I could run them from an inverter. Alternator fails use solar, 12volt on fridge fails use inverter etc...What size capacity battery do you need?
--- I thinks it’s looking like 240ah
TBCWhat physical size battery can you afford?
--- Looks like it ain’t cheap but I want to do it right so I’ll start selling the furniture!
I mean payload/physical dimensions.---Flooded seems to be the one. I’ve been looking at the Trojan batteries which have a good rep.
Flooded are king but you have to maintain them. (well you have to maintain every battery...if you treat flooded like sealed then you don't have to maintain them you are just retarding them for convenience and limiting their lifespan).
You might want to insulate, seal and ventilate your battery box. (sealed to habitation area, ventilate to atmosphere)...depends on how concerned you are about the health implications of hydrogen, solar doesn't generally cause much gasing.
Trojans are the business. Crown are better but impossible get in Éire. So much cheaper get good lead from the Uk it's silly.What sort of lifespan do you need from them.
---Is 5 years asking too much? (if treated with TLC)
Nope. That's below average for Trojans with TLC. With a good charger, care and consideration should be no problem.How often do you plan to use them?
---I’d expect to use at once a month with short weekend trips and the a couple of longer trips each year (2-3 weeks)
less than 300 cycles for 5 years.
Metering
Why is it everybody thinks this isn't necessary?
---yep metering to be included too
Good man. They're indispensable, pay once appreciate it the rest of it's life. (well...good ones that is with % SOC, the crap coloured led ones are worse than nothing)---I’m putting in underfloor fresh and waste tanks so will be including sensors for these.
It's just two wires afaik. Simple potentiometer, the water is the wiper.Why do you need a true sine inverter?
---I’ve read that you need a pure sine inverter for powering laptops.
Nope. Your laptop is 12V!!....extra low voltage DC.
Car charger unless it's a Macinposh. I don't think Apple support DC power supplies, or user serviceability, or independent repair, or in-house repair, or upgradeability, or thermal design, or part sales, or reverse compatibility, or support of "old" OS', or universal/standard connections, or standard interfaces
By all means get an inverter...mine is just for my stoopid fridge and guests.Compressor fridge or abortion fridge?
---Compressor fridge
Correct---will be looking to have central cabin lights on two switches, others on one switch.
Easy. 12v or 230V or both?
It'd bank the down-lighters in 2 per switched circuit...itsa small space.
No dimmers?---Yep, am planning on putting in conduit and labelling.
If you're using conduit single core cables will save you space and aggravation. Building regs (which do apply to campers but are never enforced) require low voltage (51VAC - 1000VAC) and extra low voltage (< 120VDC/< 50VAC) be run in separate conduit unless you use cables with [insert highest voltage here] insulation for both.---I was planning to try do it myself but maybe I’m biting off more than I can chew.
Ah you don't have to get it perfect the first time. Just be sensible and every time you fit something ask yourself can I take this out again for access. If the answer is no have a rethink.---Thanks again though for all the advice, really appreciated.
No probs.A bit of a steep learning curve for the electrics but I'll get there...one day!
Me too.
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I've just completed an LED overhaul in mine. So I thought I might lump this in here as a guide. There are other ways with mains fixtures and inverters..no redundancy, lossy (increased battery load away from shore power). Or large load compensating chargers...no redundancy. Or two isolated systems side by side...inelegant
This is my preferred method:
12V Lights with a Switched 12V Mains PSU.0 -
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I replaced my tired old 7m 45 RGB LEDs per meter with 10m of 60 RGBcW LEDs per meter.
The old ones were second hand when I bought them and I've put thousands of hours on them, they have faded.
Old RGB 45 LED per metre versus New RGBcW 60 LED per metre with Aluminium Trunking.
I added some under bed lights...
... under counter lights...
...and I took a downlighter MR16 outtov it's circuit and put it on the stiplight driver while I was at it.
Dim
> Bright
The light is fantastic more photons for less power.
One might think that double the leds use double the power but not so, first I have double the light sources so even running them at <10% there's still plenty of light. The other thing is because I've added under counter light now I'm not trying to see what I'm doing through the shadow of my head by bouncing light off the ceiling.
I'm delighted with them and the added white means colour mixing yields better less saturated colour that's more natural. With Cold White I can mix neutral white and warm white.
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The strip I got is this gubbins.
Rated at 1.6A per meter I'm running 8m for 7.4A.
I have the IP67 which is in a hollow tube, very hackable but not IP after it's nicked.
These are the drivers I'm using.
Driver #1: Controls coving RGB
Driver #2: Controls coving W, under counter Amber & MR16
Outputs are common positive.
I control them using a DMX desk. None of this app/remote carp for me, I want a tactile solution you can screw to a wall and fix with a spanner.
Channels 1-4: Ceiling Light RGBcW
Channel 5: Counter Light Intensity
Channel 6: Dimmable MR16
Under bed lights are onna cigarette lighter.
This was my battery voltage power for the Drivers (rear cig lighter plug) and 9V for the Controller (adjustable voltage cig. lighter plug).
Wiring colour code is conventional to what was in the spares drawer.0 -
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The only upsetting feature was the driver buzz. Driving me crackt.
I'm a mite irritable from electrical switching noise, the PWM hum was a raspy low level high frequency resonance. Incandescents never did this...
After many hours of gremlin routing I found most of the culprits. I tried low pass filtering, swapping drivers, data termination, grounding...:rolleyes:
This blighter was sitting on my battery bus conductor and the attenuation on the cable was inducing the buzzer speaker fields, and feeding back.
That significantly reduced the buzzuming.
Next I noticed my sockets were buzzing too.
Twas these inductors they use for fuse "retention".
Stoopidest plugs known to mankind.
I have circuit breakers for this tomfoolery!
I vanquished all the inline springs and fuses and friction connections for solder or screw clamp.
Fixt!
System deBuzzed!0 -
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OK, I'm back again. Got distracted stripping van, insulating, fitting windows etc. so now back to planning the leccy before I start pitting in floor, wall panels.
Fair play.---I'm expecting it's going to be 2-3K with panels and batteries.
This is just for electric setup
You can build a free to roam system for that easy.What is your target maximum range without plugging in?
---I?ve included a list of apps that will be used (at different stages). I?ve gone overkill on max usage times to ensure I have enough power stored. It?s coming in at 120ah so with 50% usage of batteries I guess I?m looking at minimum 240ah?s.
I appreciate you've gone overkill on the estimates, compounded by the manufacturer rating being a max threshold not nominal and you don't need the inverter so the 20% losses aren't necessary either (by the way its 20% losses at the inverter and then 10% losses of the remaining 80% to the switching supply). You've over-rated your fridge draw (it doesn't run 24 hours continuous (unless the door is open)..more like 12).
So at current estimates is 1 day range to 50% DOD with loads offset by PV.
I'd say double your battery size.
4 x Trojan T-105s;
Crowns weigh more for the equivalent rating. The T-105 will outlive a T-125 because all the active material that is shed from the plates as a natural entropic tendency during charge/recharge cycles will take longer to reach a point where it's soft shorting at the bottom of the suspended plates of a T-105 than a T-125 (which are the larger)..both have the same size case. When you look at the cost per watt of a T-105 versus a T-125 you'll find the T-105 way ahead.Looking at your comment about redundancy below then sounds like an inverter would be worth including?
As far as I'm concerned yes, they're great to have but terrible to need.
I've probably 30 hours on mine in the last 5 years and it's not because I don't use the camper. If the manufacturers of my abortion fridge had the foresight to install a thermostat on the 12v side of my fridge then that figure would be reduced to about 5.Have amended in spreadsheet
6000°K will burn the eyeballs off you. Think yard light and industrial fluorescent.
Neutral white 4000°K or Warm White 2700°K is a subjective preference.Surface Pro 3 PC
Have a look for a car "charger" so it'll run for half the power the inverter will. You may have to chop the plug and fit a high current one. Cig lighter plugs will melt, they're not fit for purpose.Updated spreadsheet attached.
Anything with a USB charge lead can be DC - DC powered for a fraction of the losses. Everything else have a look for 12volt power supplies.OK so I could have a second alternator powering up the leisures?
One can power both batteries (starter and service) from one alternator but it's just a dreadful and ubiquitous approach that the only solution to is cables with a CSA as fat as your thumb.
It's also getting increasingly difficult to do with Start/Stop systems and Ford's regen braking.
So you can spend €400 on a split charging system up to task that will split the power of one alternator across two systems or you can invest the same time and expense in two isolated systems that double your charge, redundancy and reduce your cable requirements.
Either works, both cost the same two systems are better than one.
...now some will argue that it's cheaper just stick a over-rated automotive relay between the two batteries with a coil excited by the D+....it is cheaper, it does not work. This is what manufacturers do on 2.5mm² cable with a 20A fuse between them.
The problem here is the service battery charge current is reduced to the available alternator current after the auto-electrics and associated increased losses due to heat in the windings. The regulated voltage seen by the alternator is not the service battery but the delta voltage of the starter and service battery coupled with a long and elaborate undersized wiring meander.
The losses here are non-linear if you half the voltage seen by the alternator sense wires you quarter the charge current.
It works well enough only to make the numbers of a voltmeter rise, we can do better than standard! 10X is not difficult at all.
So if you are to go down the dual alternator route, although you can get dual voltage alternators.
Why not go 24v over 12v. 12v auto-electrics and 24v service electrics? You can get 250W solar panels for 24v for the same cost of 150W 12v.
Reduced cable costs and losses. If you go for 4 Trojans just series the lot!---I'd like to install an intelligent system as opposed to manual switching etc.
Probably wise. How about an intelligent system with the option of manual switching?
Sounds good. Any recommendation?
Yes! I'm building one!;)
[teaser] I'm thinking about custom building units like this as a nixer. It's a market tester. Still in R&D I'm afraid.
It's the last box you'll ever need! Programmable, Bi-directional, Fully Automatic Split charge: Solar/Mains/Alternator, Load compensating, Temperature Compensating, Low Voltage Disconnect Circuits, Manual Battery Parallel. Comes with a Calibrated Dual-Voltmeter, Single Bi-directional Ammeter, 5M LED RGBcW Strip Lighting with a Dimmer, 1 x 1A & 1 x2.1A USB and 12VDC outlets.
You'll be wanting something bigger....this is only good for 150W mains/PV and 1kW alternator. I'll send you a link to my secret supplier.
Here's another I'm building...too big?Any recommendation here?
Well nothing is perfect. Trimetric is brilliant especially if you go for the 2030 and SC2030 as a kit. Doesn't have a relay.
Smartgauge is the only one that works accurately but doesn't have an ammeter.
Victron BMV...haven't tried it. I hear it's ok. Has a relay.
This chap might sell you a cheapy if you message him.
You mention having an inverter as part of redundancy above.
Batteries are far more reliable than inverters.Thinking 12v led downlighters plus some led strips. Switches at side and rear doors. Haven?t decided whether to use dimmers. Are they worth installing in your opinion?
Yup definately. Not only do they help with stealth and ambiance, but they also reduce your battery load proportional to their duty cycle. So you can adapt your runtime by lowering the light levels. These are real easy setup.So what steps would you recommend next?
Buy twice as much cable as you think you need.
3 core 1.5mm² flex for mains & inverter sockets in dedicated conduit.
2 core and single thin wall for extra low voltage. 1.5mm² to lights, roof fans and switches. 4mm² to fridge & DC power, 2.5mm² to air heater . 1.5mm² to everything else.
Assign a battery containment area and a cabling strategy from charge and to distribution. Allow yourself at least 1m x .75m x .3m for distribution, add a service/work light there.
Run your cables and leave 1.5m of slack tailing from every drop with a label, crack on with the conversion and let the finer points come to you as you work.0 -
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Warning: Thread HiJack Imminent...
Backround: Recently (a couple of months ago) bought a Carioca 5 on a Ducato chassis, after three painstaking years of looking for the right camper. (And I looked at alot of campers before settling on the one I bought).
Camper is usually hooked up to the house via mains, but not so since I came back last weekend. In the few days, leisure battery (under drivers seat) is reading *4.5V*. Oh dear. It's an 85Ah marine. Just for a giggle, I looked at the inverter under the passenger seat. It looks to be the standard factory fit - 200W rating (seems a little weeny to me). The space under the passenger seat looks like it might be enough to hold another battery...
I was just gonna grab a Leisure from Halfords - 115Ah on offer @ 80ish Squids (if it fits, 'tis a big yoke), and the 70Ah if it doesn't, with a view to getting a second one at some point.
BUT, can I do more?
I have switched out the downlighting and bed lamps to LED to shave a few Watts off consumption. I still have shower, water pump, compression fridge, blow heating and some USB charging station requirements. (TV in a camper van? Never! Defeats the purpose of owning one IMHO). Wild camping for a week is not a requirement, but a day or two off grid would be a sensible aim.
Eventually, I would want to put 250ish watts of solar into the mix, so I would plan for that now.
Skill Level: Very rusty Electronics Engineer. Batteries scare me slightly.
What's a suggested first step? I need a Leisure Battery, but it needs to be part of a rough master plan.0 -
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can I do more?
First essential upgrade is a decent meter.
The VDOs are just driving instruments showing instantaneous charge and discharge from batteries. Due to the shunt placement they don't register alternator power to load or Service battery load downstream of the 250A bus (unless configured to). This is because they're driving gauges and I'm protecting them from high current loads and starting inrush and the Battery Monitor is there to see the full picture.
Their purpose is to display the battery charging from the alternator and live in the dash not to be a battery monitor. The engine one on that scale will probably live around 0 most of the time and wiggle once in a blue. The Ammeters can switch between 2 shunts though so one would also suffice.
A battery monitor keeps track of the state of charge throughout a deep cycle that can last from days to weeks and provides instantaneous load/charge, volts and state of charge.
First upgrade battery monitor.
Last: Dash gauges.
I use a TriMetric and it's worth every cent.
Victron do another version.
I recently bought a shunt that came with an ApprenticeVolt job to test. I already don't like it,...the writing is too small.
SmartGauge needs a panel bidirectional ammeter installed beside it.
I've spent over €70 on carp meters off ebay now looking for a cheap accurate solution that doesn't annoy me. :rolleyes:
4.5V = 2 outtov 6 living cells.0 -
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{Notes on Revisions}: DC Distribution broken down to switched and unswitched buses to enable charger and life support local control with battery isolator open.
Preventing load supplying chargers running without a battery buffer & removing possibility of Solar VOC at solar controller PV in terminals without battery connected (PV Isolator pebcak smoke containment feature).0 -
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