My Head Hurts .....

[jo10000_6]

Hi all

My head really hurts - I feel I'm going around in circles and getting no where which annoys me greatly and as mentioned makes my head hurt.

I've posted a few times recently on :

My charger capabilities - Answer not great 7.2A charger

How long did my battery last - Answer not as long as it should

2nd Leisure Battery recommendations - Answer need better than last time

Battery Monitor - Yes Id like one

Questions on Solar - yes Id like it but do I need it.


Every time I feel I'm getting somewhere I take a step or 2 steps back and its all about making sure I make the right decisions - in the right order and for the right reasons.

All I want is a little more off grid time - not loads - 4 / 5 days Maximum.

My previous posts tell me my one battery wont do this.

My 7.2 Amp Charger will struggle

I don't have a proper split relay system although there's a crude wiring system to connect to get me out of trouble.


I was all for getting a second battery - treating myself to a battery monitor to feed my obsessions - getting them wired in together - getting the split charge sorted and having a new charger and in theory being ok until I read a an old post just earlier to say a fellow funster had a old Hymer only to find the split charge system for 2 leisure batteries and one cab battery that the alternator wasn't big enough. Another post said make sure when changing the charger that the wiring is big enough for the bigger charger.

See, backward steps all the time.

Which begs the question should I stick with one battery and pursue solar ? My roof is busy not sure what Id fit up there but the above is getting complicated by the second.

I honestly try and do the research but I'm feeling very dejected with the answers I find.

Tomorrow I will jump out of bed with a new lease of life but tonight I feel I've taken on more than I can chew.

 

[Podney]

Give up,have a large scotch,sleep well,start again tomorrow.

 

[jo10000_6]

Teetotal …..I shall have some fizzy Vimto in a wine glass

 

[obanvanman]

Give up,have a large scotch,sleep well,start again tomorrow.

What he said...but you had better make it two large ones.

 

[Phill D]

not an easy conundrum...

IMHO
bigger / better hab battery before Solar panel;
100 AH should give you 4 / 5 days unless you are using heavy stuff.

then its whats the most economical way of recharging it.....
1. is it as simple as a higher output alternator and a reasonable split charge system.
or
2. A suitable sized solar panel.


i have a 85 AH hab battery ( came with the van or i would have 100 AH ) and with my solar panel 150 watt in the summer months 4/5 days is no problem.

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[MikeD]

We have a 100w solar panel and a 140a leisure battery.

We do most of our motor homing in Spring and Autumn in Spain (mostly on sites but do wild camp a bit) and there we could last almost indefinitely for power. No heating, lots of sunshine, sitting outside not watching TV in the rain. etc.

In the UK i doubt that would be true.

Your charger may start at 7amps but will drop down to just a trickle fairly quickly and could take a day or so to recharge a pair of leisure batteries. The alternator charging the batteries will also do this. Driving for a hour will not really fully recharge depleted batteries.

Grey rainy skies in the English winter will not give you much solar charging. Watching the TV with the heating/lighting on will soon drain a leisure battery.

It really boils down to how, when and where you use the motorhome.

 

[Richard n Ann]

You could get a free standing solar panel. The big advantage is that you point it at the sun therefore it makes a LOT more power. We had a 40w free standing panel and it used to have the battery back fully charged by lunchtime.
We only use led lighting, water pump and TV for a few hours so it was more than enough. Used to charge at about 2.5a in the sun.
Even in mid winter if you stand them right up they will make near full power. For less hours though of course.

 

[Nasher]

I can squeeze 3 days (2 nights) from a single 110ah battery

I have a spilt charge system & a good quality Victron charger for EHU — so I start off with a full battery

Most times I'm away without EHU I am at a motorcycle event, so a generator charges my battery up quite quickly - but you may be camping where the noise of a generator would upset others, so not an option

Whilst solar can be great, if it rains for 3 days you won't get much charge, particularly in the winter, when the sun is low. Plus, I don't want to drill holes in my roof!

Another battery is a good option, if you have space (& payload) when my current battery dies, I will look at fitting 2. But, you will need a good charger..

If you travel daily, a B2B charger may be worth looking at providing your alternator is up to it

 

[jo10000_6]

I’ve looked at the free standing stuff - may re-visit - thanks !

I can squeeze 3 days (2 nights) from a single 110ah battery

I have a spilt charge system & a good quality Victron charger for EHU — so I start off with a full battery

Most times I'm away without EHU I am at a motorcycle event, so a generator charges my battery up quite quickly - but you may be camping where the noise of a generator would upset others, so not an option

Whilst solar can be great, if it rains for 3 days you won't get much charge, particularly in the winter, when the sun is low. Plus, I don't want to drill holes in my roof!

Another battery is a good option, if you have space (& payload) when my current battery dies, I will look at fitting 2. But, you will need a good charger..

If you travel daily, a B2B charger may be worth looking at providing your alternator is up to it

Thanks Nasher - I know the alternator isn’t up to it to be honest. I don’t travel daily either but appreciate the points above.

I suppose I could forget the split charge - have 2 batteries and the better charger ?

I’ve kinda got caught up in “if I’m doing something do it proper” now I’m realising I may need to compromise when really I don’t want to


Thanks Jo

 

[monzer]

Can't be ars*d reading through all the replies so sorry if it's been mentioned or a if it's a crap idea but have you thought about going down the generator route?

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[two]

A battery monitor (Amp-hour counter) will tell you what capacity you current battery has.
If it's poor, get another (or two identical batteries).
If you also monitor what your normal demand/consumption is, you'll know how much 'leccy you need to capture each day and how much capacity you might need in the habitation bank.
Your choices for charging are multiple and will depend on your usage pattern (where you go, when, and how often you travel).
You could throw loads of money at the solutions mentioned but you are unlikely to need them all. Without knowing the requirements, it's not easy to determine the most appropriate solution.
Sleep well. Take your time (one step at a time).

 

[Lenny HB]

You can never have too much solar or too many batteries, space and payload permitting.
We only have 300 watts of solar and 3 X 80a/h batteries and we survive.
Hymer normally fit an updated 160/180 amp alternator but I don't know if the did that when your van was built.

 

[pappajohn]

You're finding problems which don't exist.
Put a second or even third battery on and a B2B charger.
Your alternator will output what it does, it may just take a bit longer to charge a larger bank.

(A 4amp bench charger will charge a 100ah battery, just slower than a 25amp charger.)

Buy a 20amp onboard charger to replace the (suspected) 7.5amp charger (don't know any van with a 7.5amp charger)

 

[autorouter]

I don't think the 7.2 amp charger is a top priority. In theory it will give 7.2 x 24 = 172 amp-hours in a 24 hour period. In practice it will be more like 100 amp-hours, depending on how discharged your batteries become. That's enough to refill a 200 amp-hour battery bank, if you stick to the usual rule of only discharging them to 50%.

Of course if someone gives you a 15 or 20 amp charger for free, it's a good idea to upgrade, but it's not the first thing you should be looking at.

Put a second or even third battery on and a B2B charger.
Your alternator will output what it does, it may just take a bit longer to charge a larger bank.

I agree that's more like the way to go. You don't say what your alternator output is, but I'd be surprised if it's less than 50 amps, and it's probably more like 70 amps. The B2B will control the alternator and make it give out more charge, instead of throttling back when the starter battery is back up to full, which is what it's doing now.

 

[busbuddy]

All I want is a little more off grid time - not loads - 4 / 5 days Maximum.

are all your interior bulbs led, are all your 'toys' (tv,phone,laptop,etc) power hungry ?

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[Kirsten]

Hi. Sorry if this isn’t helpful ( no idea about tech so initial post way over my head...). but we often camp off grid, have one leisure battery and it has lasted fine for up to seven days with no problems( Glastonbury longest time)We go with several people- shower used daily by at least 2 people , loo has an electric flush- we use a portable solar panel pop it through roof- that charges the phones and take 2 power pack chargers charged at home aswell.Use gas for heating and also have solar lights to put outside.

 

[mitzimad]

Your priority is deciding when you want to charge if your taveling then sort out the split charging if your on ehu a bigger charger would help, for off grid then its the solar.i doubt the alternator is the problem if you can drive in the dark with the wipers and heater running.We have 180w of solar and 2x90 amphours of battery and in summer that is more than plenty in winter it gets a bit low if we dont travel for 3 days.

 

[Lenny HB]

don't know any van with a 7.5amp charger

Eairly Eltroblocks were only 7.5 amps, EBL's don't like being overloaded it you constantly charge a battery bank that is larger than they were designed for from flat they will go pop.

 

[jo10000_6]

Can't be ars*d reading through all the replies so sorry if it's been mentioned or a if it's a crap idea but have you thought about going down the generator route?

Thanks Monzer - but ideally Id like not to but appreciate the comment

 

[jo10000_6]

You're finding problems which don't exist.
Put a second or even third battery on and a B2B charger.
Your alternator will output what it does, it may just take a bit longer to charge a larger bank.

(A 4amp bench charger will charge a 100ah battery, just slower than a 25amp charger.)

Buy a 20amp onboard charger to replace the (suspected) 7.5amp charger (don't know any van with a 7.5amp charger)

I'm really not PappaJohn - I'm trying to understand what I need as a priority so I don't go in feet first and waste money that I have, but I detest wasting money (Its the Yorkshire girl in me)

And unlike yourself everything I have to do that's electrical or mechanical I don't have the option of doing it myself - hence keeping costs under control.

Its defiantly got a 7.2 amp charger though.

Appreciate your directness - I get its your way - but we are all different and how we approach stuff is always different.

I think I've said it before though - please keep the advise coming. Its much appreciated and needed.

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[jo10000_6]

I don't think the 7.2 amp charger is a top priority. In theory it will give 7.2 x 24 = 172 amp-hours in a 24 hour period. In practice it will be more like 100 amp-hours, depending on how discharged your batteries become. That's enough to refill a 200 amp-hour battery bank, if you stick to the usual rule of only discharging them to 50%.

Of course if someone gives you a 15 or 20 amp charger for free, it's a good idea to upgrade, but it's not the first thing you should be looking at.

I agree that's more like the way to go. You don't say what your alternator output is, but I'd be surprised if it's less than 50 amps, and it's probably more like 70 amps. The B2B will control the alternator and make it give out more charge, instead of throttling back when the starter battery is back up to full, which is what it's doing now.

Hi Autorouter - How do I measure alternator output ? is it easy

 

[jo10000_6]

are all your interior bulbs led, are all your 'toys' (tv,phone,laptop,etc) power hungry ?

Nearly all LEDs - I have two strips that need changing but Atenn need original lights to make adjustments to the circuit inside to take new LEDS.

TV ok at 3.5 Amps - only got a phone really

 

[jo10000_6]

Thanks all for your replies - I'm going to get the battery monitor which has previously been touched on and try to take from there.

I just need to decide which one as Id prefer not to have to make a hole in the motorhome.

When I get this fitted and if my head still is hurting then I will let you know !!

 

[two]

You don't have to cut anything to install a battery monitor. Either leave it loose within a convenient cupboard or go the whole hog and get the Victron one with bluetooth and use your mobile to monitor activity. It would have the advantage that you could easily transfer it all to your next moho (which often tends to happen rather sooner than you might expect).

 

[autorouter]

How do I measure alternator output ? is it easy

A very good question.

1. In theory you can measure it with a multimeter, by disconnecting the wire and putting the multimeter across the break so that the amps flows through the meter. That method is fraught with problems. For example, if you disconnect the battery while the alternator is running, the voltage can surge up to 60 volts or more. That will very likely cause all sorts of very expensive damage to your electronics and your electrical items. Even professionals rarely use that method.

2. You can use a clamp meter. The clamp will clip around the wire, and it measures the amps by sensing the magnetic field that the amps will produce. No need to disconnect anything. I use a UNI-T UT210E clamp meter. It's a nice neat meter that will measure small amps (1/100 of an amp) as well as large amps up to 100 amps. It has sockets for test leads and will measure volts and resistance too. It's the one I always carry in the MH.
Amazon product ASIN

3. A panel mounted volts/amps meter. Many of these are only good for 10 or 20 amps, but you will need one that can measure up to 100 amps. Like this.
https://www.ebay.co.uk/itm/100V-DC1...ED-Amp-Volt-Meter-12V-Shunt-New-/252959050501.

It has a 'shunt' through which you send all the current you want to measure. You have to disconnect the wire to connect the shunt into the main current circuit. Then there's a pair of thin wires going to the small terminals on the shunt, and another pair going to the battery positive and negative. If you wire this in permanently there's less chance of accidentally disconnecting it and causing a voltage surge.

4. Of course if you have already wired in a proper battery monitor then you can just read the amps on the display

I bet you wish you never asked that question

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[denisejoe]

Has anyone looked at his roof not a lot of room for solar?

 

[autorouter]

How do I measure alternator output ? is it easy

There's another answer to this question. If the question is whether the alternator is functioning correctly and to its full capacity, you can do this by simply measuring the voltage. It's a lot easier than all that stuff in my previous post, and it won't cause any electrical problems.

The key bit of information is that a car battery can not give out more than 13.6 volts unaided. So if you measure the battery voltage with the engine running, and it's say 14.5 volts, then the alternator must be charging OK. If it's more than 15 volts, the alternator has a problem, but that's very rare. If the battery voltage does not increase when the engine is running, to higher than when the engine is stopped, then the alternator isn't working.

Note that this simply tells you the alternator is running correctly, it doesn't tell you whether it's a 60 amp or 160 amp type

 

[jo10000_6]

A very good question.

1. In theory you can measure it with a multimeter, by disconnecting the wire and putting the multimeter across the break so that the amps flows through the meter. That method is fraught with problems. For example, if you disconnect the battery while the alternator is running, the voltage can surge up to 60 volts or more. That will very likely cause all sorts of very expensive damage to your electronics and your electrical items. Even professionals rarely use that method.

2. You can use a clamp meter. The clamp will clip around the wire, and it measures the amps by sensing the magnetic field that the amps will produce. No need to disconnect anything. I use a UNI-T UT210E clamp meter. It's a nice neat meter that will measure small amps (1/100 of an amp) as well as large amps up to 100 amps. It has sockets for test leads and will measure volts and resistance too. It's the one I always carry in the MH.
Amazon product ASIN View attachment 283087
3. A panel mounted volts/amps meter. Many of these are only good for 10 or 20 amps, but you will need one that can measure up to 100 amps. Like this.
https://www.ebay.co.uk/itm/100V-DC1...ED-Amp-Volt-Meter-12V-Shunt-New-/252959050501. View attachment 283086
It has a 'shunt' through which you send all the current you want to measure. You have to disconnect the wire to connect the shunt into the main current circuit. Then there's a pair of thin wires going to the small terminals on the shunt, and another pair going to the battery positive and negative. If you wire this in permanently there's less chance of accidentally disconnecting it and causing a voltage surge.

4. Of course if you have already wired in a proper battery monitor then you can just read the amps on the display

I bet you wish you never asked that question

Spot on !! Way to much - there's no "that's gone over my head" emoj's - My battery monitor is in transit - exciting …..I do like a gadget …….I could have said I do like a "toy" but someone would have took this comment elsewhere Im fairly sure.

 

[jo10000_6]

Hi Autorouter - I had them specifically test the alternator on a service in November - I just wished at the time I'd asked them to tell me the size but didn't need it then so Im happy its functioning OK - the battery monitor will be here in the next day or so and I will progress from there.

I've had some good sleep and some sparkling Vimto (no whiskey) and I'm back to my positive "I will get this sorted" self and has @two said I should just take my time.

I will no doubt ask for more advice when the monitor is fitted.

 

[Manic]

Nearly all LEDs - I have two strips that need changing but Atenn need original lights to make adjustments to the circuit inside to take new LEDS.

You don’t need anything fancy to change strip light to LED, I just removed all the strip light stuff, tube and driver and then stuck LED strip inside original light unit and wired to original feed.