Hi All, newbie here, love the forum, and everybody's helpfulness, its what makes this country great, me and the missus are in need of some help and advice, we have owned a jayco hawk 2000 model for over 3yrs and have only used it twice, but after some recent life changes we have decided its not all about work, and we are going to be enjoying life more and more, anyway we are going camping to a dog friendly site at Christmas, but there's no power so we have to make our own, we have a thing inside the van called a youngyear/centurion power convertor, this connects up to mains power,when your on a powered site, and I guess it converts down to 12v to run the lights, but apart from that we have nothing , no batteries zilch, we will need power for a 65L waeco, some TV which is 240v, occasional use of a microwave 240v, and power the mobile phone and laptop from time to time. I would like a solar panel but don,t know about watts amp ohms etc etc, we have an Anderson plug on the Nissan navara, so I need the complete setup, any advice, diagrams or names of mobile installers would be greatly appreciated.
Fuzzball said
08:38 PM Oct 16, 2015
Hi Merv61
We have two 150 watt solar panels and three deep cycle AGM batteries. Our caravan is set up with 12v lighting and the fridge is 240v/gas/12v which is connected to the Andersen plug. It automatically changes between the three depending on what's connected to it, at the time.
We've bought 12v TV's and they're great! The caravan has several 12v power sockets, which we charge the phones from and which power the TV's. We also have a three kva Honda generator that runs the washing machine, dryer and air conditioning, separately of course.
We've been on the road since June. Hope this helps.
Fuzzball said
08:40 PM Oct 16, 2015
Oh, and welcome to the forum. Please excuse my manners, or lack of them.
*very sheepish grin*
Aus-Kiwi said
09:34 PM Oct 16, 2015
Yep as said .. You need 300 watt solar, regulator and batteries .. We have 2 X 100 watt batteries.. 5500 watt diesel generator.. We use generator to boil jug in morning and a few time through the day .. It's enough to charge the batteries .
Yes 12v TV and charger .. I would run at least 4mm sq to prevent voltage drop to 12v outlets..
Fit a few 12v outlets in case you have portable fridge freezer .. If your planning on traveling at least every second day ?
The existing alternator or fitting another Alternator if you want to keep seperate charge system ?
To charge house batteries on the run... You cannot have too much charging with regulators ..
PeterD said
11:11 PM Oct 16, 2015
merv61 wrote:
but there's no power so we have to make our own, we have a thing inside the van called a youngyear/centurion power convertor, this connects up to mains power,when your on a powered site, and I guess it converts down to 12v to run the lights, but apart from that we have nothing , no batteries zilch, we will need power for a 65L waeco, some TV which is 240v, occasional use of a microwave 240v, and power the mobile phone and laptop from time to time. I would like a solar panel but don,t know about watts amp ohms etc etc, we have an Anderson plug on the Nissan navara, so I need the complete setup, any advice, diagrams or names of mobile installers would be greatly appreciated.
I see you have a Centurion power converter (which some people incorrectly refer to as a transformer.) These (and the alternative Setec converters) are excellent power supplies but are very poor battery chargers. Read about these devices here. When you install a battery (110 to 120 Ah) in your van I also suggest that you install a 25 A 3 or 4 stage battery charger to go with it. If you are going to install two batteries then increase that to a 50 A battery charger. With that size charger you can charge your batteries in a timely manner using your generator. Top run your rig off power you could rely on powering it by generator charging using the generator for an hour in the morning and a couple in the afternoon.
Regarding the use of a microwave oven, I suggest you forget that. The inverter required to run the oven will draw more than 150 A from your battery. That is a lot of load to impose on one or two batteries. Also at that current draw the battery capacity reduces considerably, Peukert's Law explains the capacity reduction. You will also get more from your battery if you charge your phones and things via 12 V chargers. Is your TVs power supplied from an external power supply (power brick) that plugs into the back of the TV? If it does it will most likely be a 12 V supply and you can get/make-up a lead to run the TV off the mains.
If you wish to go solar then you can mount 300 or more watts of panels on the lid of the camper. Mount a 30 A controller near the battery. Have a lead made up that you can attach it to the panels before erecting the camper and connect the remote end to a plug that feeds the controller. That way you can have your panels in the sun all day without having someone baby sit them.
merv61 said
12:50 PM Oct 17, 2015
Thanks everyone for their reply's, its baffling to say the least Peter my question to you is do I need 2 Batteries, and what size Ah wise, how long should a 300watt solar panel take in average day light to charge said battery, bearing in mind that my car should be charging the battery when I,m on the road, how do set up a battery charger in the van, is this safe? and do I get an inverter to run tv, mobile and laptop, and does it have special sockets on it, as all my power sockets in the van are for 240v, and finally do i hook up to the centurion convertor for the lighting which is 12v. Oh yeah what about a regulator/ battery monitor, and switch for between car and van batteries???
Jaahn said
04:26 PM Oct 17, 2015
merv61 wrote:
Thanks everyone for their reply's, its baffling to say the least Peter my question to you is do I need 2 Batteries, and what size Ah wise, how long should a 300watt solar panel take in average day light to charge said battery, bearing in mind that my car should be charging the battery when I,m on the road, how do set up a battery charger in the van, is this safe? and do I get an inverter to run tv, mobile and laptop, and does it have special sockets on it, as all my power sockets in the van are for 240v, and finally do i hook up to the centurion convertor for the lighting which is 12v. Oh yeah what about a regulator/ battery monitor, and switch for between car and van batteries???
Hi Merv61,
If I was in your position I would be extending my knowledge a bit more by some light reading before I would spend my hard earned money. Lots of people on here seem to flannel around with ideas that come from a salesman, the net, the man down the pub or even the forum here. However we are not really aware of your particular situation and there could be up to several $1000s or more to spend to get set up. Some people spend lots more than that and complain it still does not do what they want.
Colyn Rivers has put out some books on this subject particularly for camping too and they are available on line and in some places around, and even THE LIBRARY for free probably !! Read a bit then you will know what to ask about.
His website;
http://caravanandmotorhomebooks.com/
Cheers jaahn
Santa said
06:27 PM Oct 17, 2015
Jaahn wrote:
merv61 wrote:
Thanks everyone for their reply's, its baffling to say the least Peter my question to you is do I need 2 Batteries, and what size Ah wise, how long should a 300watt solar panel take in average day light to charge said battery, bearing in mind that my car should be charging the battery when I,m on the road, how do set up a battery charger in the van, is this safe? and do I get an inverter to run tv, mobile and laptop, and does it have special sockets on it, as all my power sockets in the van are for 240v, and finally do i hook up to the centurion convertor for the lighting which is 12v. Oh yeah what about a regulator/ battery monitor, and switch for between car and van batteries???
Hi Merv61,
If I was in your position I would be extending my knowledge a bit more by some light reading before I would spend my hard earned money. Lots of people on here seem to flannel around with ideas that come from a salesman, the net, the man down the pub or even the forum here. However we are not really aware of your particular situation and there could be up to several $1000s or more to spend to get set up. Some people spend lots more than that and complain it still does not do what they want.
Colyn Rivers has put out some books on this subject particularly for camping too and they are available on line and in some places around, and even THE LIBRARY for free probably !! Read a bit then you will know what to ask about.
His website;
http://caravanandmotorhomebooks.com/
Cheers jaahn
+ 1 from me Jaahn, excellent advice.
Welcome to the forum Merv and good luck with your project.
Thanks everyone for their reply's, its baffling to say the least
1.. Peter my question to you is do I need 2 Batteries, and what size Ah wise,
2.. how long should a 300watt solar panel take in average day light to charge said battery, bearing in mind that my car should be charging the battery when I,m on the road,
3.. how do set up a battery charger in the van, is this safe? and
4.. do I get an inverter to run tv, mobile and laptop, and does it have special sockets on it, as all my power sockets in the van are for 240v, and
5.. finally do i hook up to the centurion convertor for the lighting which is 12v.
6.. Oh yeah what about a regulator/ battery monitor, and switch for between car and van batteries???
Well Merv, the more questions we answer the more questions it generates for you. If we answer all your queries then we will probably have filled enough space on this thread to write a considerable portion of Collyn Rivers books. There was a mention that you should read at least one of his books, I support that idea.
1.. The batteries we use in our vans are around the 110 Ah size, some are as small as 100 AH and some over 120 Ah. It's not a simple question of how many you can carry amongst the rest of the loading and not exceed the meagre limit that some van manufacturers allow you. The more solar you have the and whether you are prepared to use your generator a bit can reduce the size battery bank you can get away with. I have an absorption fridge so I have no personal experience in running inbuilt compressor fridges over a long time. Way back I did run a 35 l Waeco fridge on a 110 Ah battery and would squeeze 2 days between powered sites. Many forum members survive with a portable fridge, one battery and a 200 - 300 W array of panels. try that for starters and see how you go. Carry your generator to get yourself out of trouble if the batteries don't cope. For your first trip you can just use your battery without panels just using your generator to charge it. That way you can see how long your battery can run between charges.
2.. What is average daylight? This varies depending on the season and how far south you are. Your charge time will be dependent on how far you have let your batteries go down. If you are travelling each day with your van then you will be less reliant on your battery charge from your panels. No one can answer your question unless they have the full details of your system and where you are located. Some of Collyn's books have charts showing the number of average sun hours you can expect over the whole of Oz for both summer and winter.
3.. This question leads me to think that you are referring to the portable types used by repair places and in the home garage. They are not very well regulated and will destroy batteries if they are left on charge for a week or more. Get yourself a quality multi stage charger like a Ctek or similar. These start with a boost charge, the current flow will be the rated charge rate of the device. When the charge level is built up to 80% or more very quickly (if you are using a large enough model) and then switch to an absorption charge to finish the job off and then drop down to a maintenance or float charge. These may be left permanently connected to your battery. There is monitoring built into the multi stage chargers to prevent them damaging your batteries (if you have selected the correct charger for the particular style of battery you have.)
4.. I am not a great fan of inverters so I will say don't get one. They waste power doing their job. Most things I would need an inverter to run have 12 V powered equivalents. I use those. Inverters have power points on them. I do carry a small inverter for when there is no other way out. It connects to the battery through a short cable and I plug the appliance directly in the inverter power socket. If you wish to connect your inverter to your vans electrical system you will need to get an electrician to install the changeover circuitry. Its easier for an electrician to supply and mount a double power point in a convenient spot and cable the inverter directly to that.
5 The Centurion is already connected to your 12 V lights. There is a battery connection on the Centurion to connect up to your battery. When you are on shore power (240 V in a park) the Centurion will keep your battery topped up. The Centurion is not a very good quick recovery charger so you simply connect your 240 V charger and your solar system directly to the battery. The three charging devices will not fight each other. Everything sits there nicely in harmony and when the shore power fails or is disconnected your lights and other small 12 V devices will carry on operating from the battery.
6.. I think I have answered most of this in 5.. To keep your cranking batteries apart when the tugs motor is not running you can simply detach the umbilical cable from the tug. You would not need to do this for lunch stops when travelling. If you require something more elaborate then use an ignition controlled solenoid/relay or a voltage sensing battery controller in your tug.
Sorry for the delay in replying, I have been busy with other things and am not a very fast typist.
-- Edited by PeterD on Monday 19th of October 2015 12:38:40 PM
merv61 said
06:46 PM Oct 19, 2015
Thanks Peter
I know I sound like a right Wally but I want to get it right First time, and obviously get someone who knows what there doing to install it.
wasn_me said
09:25 AM Oct 20, 2015
PeterD wrote:
I see you have a Centurion power converter (which some people incorrectly refer to as a transformer.) These (and the alternative Setec converters) are excellent power supplies but are very poor battery chargers. Read about these devices here. When you install a battery (110 to 120 Ah) in your van I also suggest that you install a 25 A 3 or 4 stage battery charger to go with it. If you are going to install two batteries then increase that to a 50 A battery charger. With that size charger you can charge your batteries in a timely manner using your generator. Top run your rig off power you could rely on powering it by generator charging using the generator for an hour in the morning and a couple in the afternoon.
Hi PeterD
I have just purchased a 2 year old Jayco Discovery. It has a Setec ST35-11. The user instructions claim it to be a four stage 15 amp battery charger with (boost 14.05 volts) (float 13.65 volts) (store 13.25 volts) (trickle charge, voltage not stated)
The boost voltage is higher than "typical 13.65 volts" quoted in the attached article. Have these units been improved as a battery charger??
I have had nothing to do with these power supply- battery charger units in the past, as I mainly rely on solar. My last van was purely solar, with no battery charger.
Cheers Pete
PeterD said
06:57 PM Oct 20, 2015
wasn_me wrote:I have just purchased a 2 year old Jayco Discovery. It has a Setec ST35-11. The user instructions claim it to be a four stage 15 amp battery charger with (boost 14.05 volts) (float 13.65 volts) (store 13.25 volts) (trickle charge, voltage not stated)
The boost voltage is higher than "typical 13.65 volts" quoted in the attached article. Have these units been improved as a battery charger??
Go back to your handbook and note how long that 14.05 V boost is on for. It is only on for 15 minutes after the charger is on for 24 hours and then every 24 hours after that.. That is useless for battery charging. All the other voltages are way too low for charging the battery quickly. The handbook acknowledges that.
Ensure battery has being charged for several days before a major camping trip (Leave the power supply on for at least 2 5 days with battery connected).
and again
AC/DC Power Supply: This provides an isolated 13.65Vdc output for powering of the load and float charging of the battery.
There is no mention of bulk or absorption charging that quality battery chargers supply. The Setec or Centurion power supplies are excellent for powering the 12 V systems in a van and trickle charging. They are hopeless when it comes to charging batteries in a timely manner. If you are out in the bush you don't want your generator running for a few days continuously to recharge your batteries.
-- Edited by PeterD on Tuesday 20th of October 2015 06:58:33 PM
Aus-Kiwi said
09:55 PM Oct 20, 2015
Yep bought a generic 50 amp charger some time back to quick charge my cars .. As stupid alarms flatten new battery in just over a week !! I have put this charger on 2 X 100 w/h battery and the breaker keeps tripping off and on till it charges..
Maybe I should charge one at a time ? It comes good when charged .. I think these high A/H batteries require higher amperage to charge them? Most alternators are way over 80 amps now ..
wasn_me said
07:58 AM Oct 21, 2015
PeterD wrote:
There is no mention of bulk or absorption charging that quality battery chargers supply. The Setec or Centurion power supplies are excellent for powering the 12 V systems in a van and trickle charging. They are hopeless when it comes to charging batteries in a timely manner. If you are out in the bush you don't want your generator running for a few days continuously to recharge your batteries.
-- Edited by PeterD on Tuesday 20th of October 2015 06:58:33 PM
Thanks for the reply PeterD. My van has a solar set up that supplies all I need. I mostly bush camp.
I thought the setec would be a good back up (240 volt charger) if ever needed. It appears it's just an expensive battery isolation switch, if bush camping.
I bought a 1kva honda many years ago for back up to charge batteries. I carted it around for about 12 months & never used it, so it gathers dust in the garage now. I spent 5 months in the van at the beginning of this year & battery never got below 12.3 volts.
Cheers Pete
Fuzzball said
01:43 PM Oct 21, 2015
We just looked into prices from several caravan places, and went with the one that provided us with what we needed at a good price. Talk to caravan places, especially ones that outsource their work. The solar people that they have working for/with them really do know what they're talking about.
merv61 said
08:42 PM Oct 27, 2015
Just a quick question for Peter, i'm going to be getting a 160 watt solar panel, with 1- 135AH battery, so the plan is for the solar panel to charge the battery, but do I still need some sort of battery monitor to tell me what charge is in the Battery? And is there any point in getting the Ctek charger, as there is no 240v power.
PeterD said
11:19 PM Oct 27, 2015
First a bit on terminology - To me a battery monitor is something like this - it provides SOC (state of charge) monitoring. You can alternatively use a simple volt meter as a quick (although not accurate) check on your battery. I would suggest you get at least a volt meter.
I do not have a full battery monitor in my van, I would like one but they were very expensive when I got my van and I have learnt to live without one. The solar controller I have has a battery volt meter on it. I don't get too concerned providing that the voltage does not get down near 12 V whilst I am using 12 V power.
If the controller you get to go with the solar panel does not have a volt meter then you could install a cheap one in the van. Alternatively you should have a digital volt meter and learn how to use it (if you don't already know how to use one.) Just install a point somewhere in the van where you can easily check the battery voltage with your meter. Check the voltage several times a night until you get the hang of how the battery performs.
-- Edited by PeterD on Tuesday 27th of October 2015 11:21:01 PM
Hi All, newbie here, love the forum, and everybody's helpfulness, its what makes this country great, me and the missus are in need of some help and advice, we have owned a jayco hawk 2000 model for over 3yrs and have only used it twice, but after some recent life changes we have decided its not all about work, and we are going to be enjoying life more and more, anyway we are going camping to a dog friendly site at Christmas, but there's no power so we have to make our own, we have a thing inside the van called a youngyear/centurion power convertor, this connects up to mains power,when your on a powered site, and I guess it converts down to 12v to run the lights, but apart from that we have nothing , no batteries zilch, we will need power for a 65L waeco, some TV which is 240v, occasional use of a microwave 240v, and power the mobile phone and laptop from time to time. I would like a solar panel but don,t know about watts amp ohms etc etc, we have an Anderson plug on the Nissan navara, so I need the complete setup, any advice, diagrams or names of mobile installers would be greatly appreciated.
Yes 12v TV and charger .. I would run at least 4mm sq to prevent voltage drop to 12v outlets..
Fit a few 12v outlets in case you have portable fridge freezer .. If your planning on traveling at least every second day ?
The existing alternator or fitting another Alternator if you want to keep seperate charge system ?
To charge house batteries on the run... You cannot have too much charging with regulators ..
I see you have a Centurion power converter (which some people incorrectly refer to as a transformer.) These (and the alternative Setec converters) are excellent power supplies but are very poor battery chargers. Read about these devices here. When you install a battery (110 to 120 Ah) in your van I also suggest that you install a 25 A 3 or 4 stage battery charger to go with it. If you are going to install two batteries then increase that to a 50 A battery charger. With that size charger you can charge your batteries in a timely manner using your generator. Top run your rig off power you could rely on powering it by generator charging using the generator for an hour in the morning and a couple in the afternoon.
Regarding the use of a microwave oven, I suggest you forget that. The inverter required to run the oven will draw more than 150 A from your battery. That is a lot of load to impose on one or two batteries. Also at that current draw the battery capacity reduces considerably, Peukert's Law explains the capacity reduction. You will also get more from your battery if you charge your phones and things via 12 V chargers. Is your TVs power supplied from an external power supply (power brick) that plugs into the back of the TV? If it does it will most likely be a 12 V supply and you can get/make-up a lead to run the TV off the mains.
If you wish to go solar then you can mount 300 or more watts of panels on the lid of the camper. Mount a 30 A controller near the battery. Have a lead made up that you can attach it to the panels before erecting the camper and connect the remote end to a plug that feeds the controller. That way you can have your panels in the sun all day without having someone baby sit them.
Hi Merv61,
If I was in your position I would be extending my knowledge a bit more by some light reading before I would spend my hard earned money. Lots of people on here seem to flannel around with ideas that come from a salesman, the net, the man down the pub or even the forum here. However we are not really aware of your particular situation and there could be up to several $1000s or more to spend to get set up. Some people spend lots more than that and complain it still does not do what they want.
Colyn Rivers has put out some books on this subject particularly for camping too and they are available on line and in some places around, and even THE LIBRARY for free probably !! Read a bit then you will know what to ask about.
His website;
http://caravanandmotorhomebooks.com/
Cheers jaahn
+ 1 from me Jaahn, excellent advice.
Welcome to the forum Merv and good luck with your project.
thegreynomads.activeboard.com/f618611/solar-power/
Well Merv, the more questions we answer the more questions it generates for you. If we answer all your queries then we will probably have filled enough space on this thread to write a considerable portion of Collyn Rivers books. There was a mention that you should read at least one of his books, I support that idea.
1.. The batteries we use in our vans are around the 110 Ah size, some are as small as 100 AH and some over 120 Ah. It's not a simple question of how many you can carry amongst the rest of the loading and not exceed the meagre limit that some van manufacturers allow you. The more solar you have the and whether you are prepared to use your generator a bit can reduce the size battery bank you can get away with. I have an absorption fridge so I have no personal experience in running inbuilt compressor fridges over a long time. Way back I did run a 35 l Waeco fridge on a 110 Ah battery and would squeeze 2 days between powered sites. Many forum members survive with a portable fridge, one battery and a 200 - 300 W array of panels. try that for starters and see how you go. Carry your generator to get yourself out of trouble if the batteries don't cope. For your first trip you can just use your battery without panels just using your generator to charge it. That way you can see how long your battery can run between charges.
2.. What is average daylight? This varies depending on the season and how far south you are. Your charge time will be dependent on how far you have let your batteries go down. If you are travelling each day with your van then you will be less reliant on your battery charge from your panels. No one can answer your question unless they have the full details of your system and where you are located. Some of Collyn's books have charts showing the number of average sun hours you can expect over the whole of Oz for both summer and winter.
3.. This question leads me to think that you are referring to the portable types used by repair places and in the home garage. They are not very well regulated and will destroy batteries if they are left on charge for a week or more. Get yourself a quality multi stage charger like a Ctek or similar. These start with a boost charge, the current flow will be the rated charge rate of the device. When the charge level is built up to 80% or more very quickly (if you are using a large enough model) and then switch to an absorption charge to finish the job off and then drop down to a maintenance or float charge. These may be left permanently connected to your battery. There is monitoring built into the multi stage chargers to prevent them damaging your batteries (if you have selected the correct charger for the particular style of battery you have.)
4.. I am not a great fan of inverters so I will say don't get one. They waste power doing their job. Most things I would need an inverter to run have 12 V powered equivalents. I use those. Inverters have power points on them. I do carry a small inverter for when there is no other way out. It connects to the battery through a short cable and I plug the appliance directly in the inverter power socket. If you wish to connect your inverter to your vans electrical system you will need to get an electrician to install the changeover circuitry. Its easier for an electrician to supply and mount a double power point in a convenient spot and cable the inverter directly to that.
5 The Centurion is already connected to your 12 V lights. There is a battery connection on the Centurion to connect up to your battery. When you are on shore power (240 V in a park) the Centurion will keep your battery topped up. The Centurion is not a very good quick recovery charger so you simply connect your 240 V charger and your solar system directly to the battery. The three charging devices will not fight each other. Everything sits there nicely in harmony and when the shore power fails or is disconnected your lights and other small 12 V devices will carry on operating from the battery.
6.. I think I have answered most of this in 5.. To keep your cranking batteries apart when the tugs motor is not running you can simply detach the umbilical cable from the tug. You would not need to do this for lunch stops when travelling. If you require something more elaborate then use an ignition controlled solenoid/relay or a voltage sensing battery controller in your tug.
Sorry for the delay in replying, I have been busy with other things and am not a very fast typist.
-- Edited by PeterD on Monday 19th of October 2015 12:38:40 PM
I know I sound like a right Wally but I want to get it right First time, and obviously get someone who knows what there doing to install it.
Hi PeterD
I have just purchased a 2 year old Jayco Discovery. It has a Setec ST35-11. The user instructions claim it to be a four stage 15 amp battery charger with (boost 14.05 volts) (float 13.65 volts) (store 13.25 volts) (trickle charge, voltage not stated)
The boost voltage is higher than "typical 13.65 volts" quoted in the attached article. Have these units been improved as a battery charger??
I have had nothing to do with these power supply- battery charger units in the past, as I mainly rely on solar. My last van was purely solar, with no battery charger.
Cheers Pete
Go back to your handbook and note how long that 14.05 V boost is on for. It is only on for 15 minutes after the charger is on for 24 hours and then every 24 hours after that.. That is useless for battery charging. All the other voltages are way too low for charging the battery quickly. The handbook acknowledges that.
and again
There is no mention of bulk or absorption charging that quality battery chargers supply. The Setec or Centurion power supplies are excellent for powering the 12 V systems in a van and trickle charging. They are hopeless when it comes to charging batteries in a timely manner. If you are out in the bush you don't want your generator running for a few days continuously to recharge your batteries.
-- Edited by PeterD on Tuesday 20th of October 2015 06:58:33 PM
Maybe I should charge one at a time ? It comes good when charged .. I think these high A/H batteries require higher amperage to charge them? Most alternators are way over 80 amps now ..
Thanks for the reply PeterD. My van has a solar set up that supplies all I need. I mostly bush camp.
I thought the setec would be a good back up (240 volt charger) if ever needed. It appears it's just an expensive battery isolation switch, if bush camping.
I bought a 1kva honda many years ago for back up to charge batteries. I carted it around for about 12 months & never used it, so it gathers dust in the garage now. I spent 5 months in the van at the beginning of this year & battery never got below 12.3 volts.
Cheers Pete
First a bit on terminology - To me a battery monitor is something like this - it provides SOC (state of charge) monitoring. You can alternatively use a simple volt meter as a quick (although not accurate) check on your battery. I would suggest you get at least a volt meter.
I do not have a full battery monitor in my van, I would like one but they were very expensive when I got my van and I have learnt to live without one. The solar controller I have has a battery volt meter on it. I don't get too concerned providing that the voltage does not get down near 12 V whilst I am using 12 V power.
If the controller you get to go with the solar panel does not have a volt meter then you could install a cheap one in the van. Alternatively you should have a digital volt meter and learn how to use it (if you don't already know how to use one.) Just install a point somewhere in the van where you can easily check the battery voltage with your meter. Check the voltage several times a night until you get the hang of how the battery performs.
-- Edited by PeterD on Tuesday 27th of October 2015 11:21:01 PM