Batteries off grid - my findings - my fix

[Don Quixote]

Today starting drawing amps from batteries, around 5.5ish from 9am until 4pm and according to the BMV 600S that was 26.7amps drawn and voltage was 12.6 when I started the engine and run on tickover.
Very surprised and pleased to see the voltage go to 14.45 and the amps to 38, but be the time I took photo is was 35.9 amps. I left engine running for 25 minutes and got bored watching the BMV 600S dropping amps down to 6.6amps, so switched of engine.
Conclusion: well worth fitting and now I have a CTEK battery charger and a Honda 10i generator for sale ( will take them to Pedro's in Portugal see if anyone makes an offer.
Be interested in replies and any questions.

 

[Touringtheworldslowly]

Impressive

 

[DBK]

I'm not sure you have given the setup much of a test, impressive though the work to date is. I assume your 26.7 figure is amp-hours in which case you drew less than 10% of the charge from your 3 battery setup.

The system responded by whacking over 30 amps into the batteries. They may have no problem with this, but I think this is the nub of the issue. What is the long term effect of this sort of cycle on both the vehicle and the batteries.

Only time will tell and I look forward to any updates. Many thanks for your work.

 

[jonandshell]

I'm not sure you have given the setup much of a test, impressive though the work to date is. I assume your 26.7 figure is amp-hours in which case you drew less than 10% of the charge from your 3 battery setup.

The system responded by whacking over 30 amps into the batteries. They may have no problem with this, but I think this is the nub of the issue. What is the long term effect of this sort of cycle on both the vehicle and the batteries.

Only time will tell and I look forward to any updates. Many thanks for your work.

It depends on the ability and quality of the batteries.

Our 345Ah traction bank is charged at rates of up to 120amps. The batteries are six years old and have full capacity.

 

[Ivory55]

What would 345ah traction batteries cost us normal people aprox, not trade to you ? Just out of interest cheers

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[DBK]

It depends on the ability and quality of the batteries.

Our 345Ah traction bank is charged at rates of up to 120amps. The batteries are six years old and have full capacity.

Exactly, what sort of batteries are fitted must be a factor. My instinct is plain old lead-acid are probably best for this sort of cycle - but I wouldn't claim for a moment to be fully up to speed on the different technologies. There are always tradeoffs too.

 

[jonandshell]

What would 345ah traction batteries cost us normal people aprox, not trade to you ? Just out of interest cheers

Much cheaper than you think!

http://www.justcarbatteries.co.uk/specialist-batteries/dyno-specialist-batteries.html

 

[Cal54]

It would be great if there was an educational meet with one of you knowledgeable people being teacher. I would love to learn more but it just seems a lot to try and understand in a thread. Fantastic thread though.

I would love there to be a meet that explained all this tech stuff that I know nothing about! I just press the button to see if I have a green, amber or red light but would like to understand more.

 

[rolandrat]

Very interesting reading but why would anyone need 3+100amp batteries unless you have a hungry diesel heating system or a compressor fridge fitted. I have an 80 amp battery plus a 100 watt Solar panel and have never ever had a power problem or flat battery. We go on many long weekend rallies without hook up and have ample power for what we need. The other thing to bear in mind is the extra weight being carried with 2 extra batteries, the generator and the fuel as well.

 

[bungy]

Very interesting reading but why would anyone need 3+100amp batteries unless you have a hungry diesel heating system or a compressor fridge fitted. I have an 80 amp battery plus a 100 watt Solar panel and have never ever had a power problem or flat battery. We go on many long weekend rallies without hook up and have ample power for what we need. The other thing to bear in mind is the extra weight being carried with 2 extra batteries, the generator and the fuel as well.

Key point......

Some folks have lots of gadgets and things which need more power, some have inverters for hairdryers, micro waves etc, some have solar some don't, some folks stay for a week or two off hookup others dont...and some just because they can and want a project to do etc

and quite a few have none of the above and have minimal requirements - Horses for course really

Always good to have alternatives incase things change

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[jonandshell]

Very interesting reading but why would anyone need 3+100amp batteries unless you have a hungry diesel heating system or a compressor fridge fitted. I have an 80 amp battery plus a 100 watt Solar panel and have never ever had a power problem or flat battery. We go on many long weekend rallies without hook up and have ample power for what we need. The other thing to bear in mind is the extra weight being carried with 2 extra batteries, the generator and the fuel as well.

Skiing!

Dont have a generator either, a Sterling Alternator to Battery system is far more effective.

Plus the above post perpetuates the myth that all diesel heating uses excessive 12v power. This isn't the case, you only need to compare the ratings of a Truma Combi 6 and a Webasto Dualtop. There is very little difference.

 

[dabhand]

Key point......

Some folks have lots of gadgets and things which need more power, some have inverters for hairdryers, micro waves etc, some have solar some don't, some folks stay for a week or two off hookup others dont...and some just because they can and want a project to do etc

and quite a few have none of the above and have minimal requirements - Horses for course really therefore fix the

Always good to have alternatives incase things change

And some have no idea why their batteries go flat and cannot figure out why and have to get their van started by another funster (Thanks again Terry, see Lincoln Rally 2014) So I love all this chat about batteries, but I'm still in the dark (must be the battery LOL)

 

[Cal54]

Perhaps we could have instruction sessions arranged at the Warners meets, as there is usually a good turn out. If there was an 'idiots guide' hour I would def attend. Needs to be real 'Janet and John' level for me. Others would no doubt like more advanced info and that could be another session. Just a thought.

 

[dabhand]

Perhaps we could have instruction sessions arranged at the Warners meets, as there is usually a good turn out. If there was an 'idiots guide' hour I would def attend. Needs to be real 'Janet and John' level for me. Others would no doubt like more advanced info and that could be another session. Just a thought.

Think I'd need more than an hour

 

[rolandrat]

Skiing!

Dont have a generator either, a Sterling Alternator to Battery system is far more effective.

Plus the above post perpetuates the myth that all diesel heating uses excessive 12v power. This isn't the case, you only need to compare the ratings of a Truma Combi 6 and a Webasto Dualtop. There is very little difference.

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[Abacist]

Today starting drawing amps from batteries, around 5.5ish from 9am until 4pm and according to the BMV 600S that was 26.7amps drawn and voltage was 12.6 when I started the engine and run on tickover.
Very surprised and pleased to see the voltage go to 14.45 and the amps to 38, but be the time I took photo is was 35.9 amps. I left engine running for 25 minutes and got bored watching the BMV 600S dropping amps down to 6.6amps, so switched of engine.
Conclusion: well worth fitting and now I have a CTEK battery charger and a Honda 10i generator for sale ( will take them to Pedro's in Portugal see if anyone makes an offer.
Be interested in replies and any questions.
View attachment 44019 View attachment 44020 View attachment 44021

Very interested in this and thank you very much for the posts and pics!

Could you itemise the components used and their costs so we can see the total cost. This would help those of us less confident in what to do and get?

 

[Jaws]

At Newark I bought a pair of Duracel 145aH batteries.
Fitted them and added another 100w solar panel to the bank giving 300watts in total

We arrived at Lincoln on Thursday around mid day
We do watch a fair bit of telly and have a 22" jobby which draws a fair old whack of juice, along with the Sky Pace system
By the time we left on Monday the batteries were reading 12.4v off charge.. So basically the system had handled everything we could throw at it for the 4 days and it was still fully charged !

I am a happy bunny

 

[Don Quixote]

Up date: 14 July 2015
Been in the UK now for 70 days of which 10 days I used EHU ( it was there so used it ) 60 days off grid. Only change to setup is added 80watt panel to roof total now 200watts and Eddies "battery master". The UK weather has been good as far as sun goes, but none the less I get something solar wise each day. I have only used the B2B when moving as have found solar works fine with my 330amps of power from batteries.

Findings:
(a) Parked up without engine using B2B for up to 21 days without moving. I also have Eddie's bit of kit thats charges the vehicle battery from the LB's, which I recommend 100%
(b) Taken from batteries average day is 25 amps ( LED lights, charging phones, fridge, computer, using TV for 4/5 hours etc etc ) I can break it down to each item to the amp.
(c) The solar regular is a MPPT which "smartly" monitors the batteries and will when there is enough sun power will charge the batteries at 14.4volts, but most of the time only tops up at 13.8 or less. Most days by 14:00hrs the batteries at 100% full.
Picture of Solar regular:

(d) Total days with some sun!!= 31 ( average solar energy total light hours is 15 hours ) = 45 amps return. Some days I have been getting 13/15 amps in small bursts, but when the regular deduces that the batteries all fully charge at 14.4 volts it drops amps to a trickle ( wasted solar at this stage )
Even on a day with total cloud cover (like passed 3 days!!!) I can get around 1.5/2 amps most of the day, however this is now enough to top up batteries.
(e) When driving the B2B comes into it's own and FULLY charges the batteries at 14.4volts and after about 35/55 minutes the victron 600s monitor tells me 0.0amps being added from B2B, which every 20 minutes the B2B checks again whilst engine running.

Conclusion: Without doubt solar rules here and the more solar power you can draw/fit the better off your batteries will be. Fit a MPPT solar regular as they deliver up to 30% power from the panels. Get one that has a "read out" so you can see what your getting from the sun and not guessing......

Next update will be after my return to Spain in September where I can report finding when I have wall to wall sun shine..........

 

[KalaCruise]

Morning, I thought I would give my batteries a good "bashing" whilst in the UK for 3 weeks and would like to share with members on here my findings as I have read all the posts on here about "my battery is dead" or "why is my onboard charger not changing my battery" or "why does my engine not charge my batteries whilst running parked up"

Firstly I have the following:

(a) 3 x 110amp hour battery - These are in good condition and hold charge well.

(b) Victron BMV 600S - This is by far the best thing for monitoring your 12 volt system.

(c ) CBE charging system as fitted by MH manufacture - After many hours of searching the CBE system I have 2 x Safety relays EPC they are both in front of the CBE box.
Photo:

The inside of the case with the relay, fuse 50Amp (power circuit) and one 5 Amp. (Control circuit relay)

(c) Solar panel 80watts - A 80 Watt solar panel will give you about 320 Watt-hours of energy on a summer day. For a 12 volt system, that corresponds to 26.7 Amp-hours put back into your battery bank each day. On sunny days, you will get more; on overcast days you will get less. So in Winter, your 80 Watt solar panel will only be giving you about 80 Watt-hours of energy per day in the worst case. For a 12 volt battery, that corresponds to 6.7 Amp-hours put back into your battery bank each day .
(d) Ctek MXS 25 main charger - This runs off mains supply (EHU) or gene ( no problems with 10i ) It will start off charging at 14.6 and drop down over a period to 13.5 - start up can be 16/18amps then down to 0.1 amps depending on how long you run the gene for. I have found that after 2/3 hours the batteries are charged with NO load on the batteries.

(e) Honda 10i Generator - This was bought after being recommended by many people as being the best out there. To date I have used it a handful of times, however over the past week it has been on most nights for this test.

Findings:

A typical night parked up we would have a few LED lights on the TV and Sat system with tuner box. At most about 4.5amps for 4/5 hours and as and when the water pump ( for cuppa etc ) so quick 3/4 amps. The batteries lasted first night no problem and the second, however by the third night voltage is around the 12.4 mark, that is without moving or charging. During the day here in the UK the solar panel is at best just taking up room on the roof. So happy enough I thought the batteries and charging system were doing what they should.

Now as many on here think - no problem, I will start the engine and that will charge the batteries whilst I'm parked up....... NOT so as such because it takes hours of engine running just to add a few amps. A battery needs about 120% INPUT to get to full charge...so...your 110 leisure battery/batteries would need: 110 x 120% = 130Amps per hour. I have 3 x 100!!! Normal charging rate is at 10% for best life...SO.....13A for 10 hours and as most alternators will charge....14.2 - 14.4V at about 2000rpm it will drop the amps from 5/6/7/8 at start to 0.2 after 1 or 2 hours of running. So after that you are only trickle charging so that when you park up the batteries look good for about 1 or 2 hours and then the voltage drops very quickly. At this point many think that their batteries are destroyed because they wrongly or rightly think the run/drive should have charged/them.............

So running a gene would resolve the problem....... well sort of.... the gene can only put in xxx amps so the same effect happens unless you're running it for hours on end ( not recommended in a busy location - at best you will annoy people off at worst it will get stolen! ) so I thought why not try a........

CTEK MXS 25 Mains charger which would work whilst on EHU and for use on the generator. Well it works great on EHU conditioning the batteries and can on the generator charge the batteries in 1/2 hours ( with NO LOAD ) pushing into the batteries 14/16/18 amps depending on state of charge, however again the generator has to be run. Please note I do not use the word "fully" as the following conditions apply: 2 hours at 10A = 20 - 5 hours at 5A = 25 - 10 hours at 3A = 30 and 20 hours at 1A = 20 (The last one is your engine running! )

So now what next.......... Well if you're never "off grid" you have nothing to worry about. If you are "off grid" once in a blue moon again you have nothing to worry about as in both cases your on board charger will sort things out for you as soon as you return to EHU.
If however you plan to use your MH without paying for the privilege of EHU then I hope the above helps you understand that in the case of 12 volt you need more than the standard charging system fitted to most motorhomes.

Keeping your batteries charged off grid is a bit of a black art and as many do not fully understand the charging system that they have fitted in the motorhome I thought my findings might be of use to others ( don't forget the like button )

I have ordered a sterling battery to battery charger and hope to fit it before leaving the UK to head back home to Spain, but I'm not too worried if I don't. My plan is to get rid of the gene as carrying it means carrying petrol too.

I will update this post when I have had the sterling battery to battery charger fitted and tested.

Any feedback on the sterling battery to battery charger from those who have fitted it would be great and even better if you have fitted it with a CBE system.

Thanks for reading.

Interesting read, makes a lot of sense. But what does'nt is all that battery power and just 80 watts of Solar on your roof. Why don't you stick 200 watts up there?

 

[Don Quixote]

@KalaCruise perhaps you did not read the above post fully, I do have 200watts and the post above is 2 years old.
Still running the same batteries which are holding up well, but for now MH is in storage (solar charging the batteries) whilst we are away doing others things.

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