My motorhome has two 105 AH deep cycle batteries in parallel that provide the power independent of the vehicles starting battery, I need to buy a new battery charger to keep them in a state of charge at home during long periods when I don't use the vehicle. I have been looking around and don't know if I should buy a model that produces 5, 10, 15, 20, or 40 amp output or whether it wouldn't make any difference. Would the lesser output just take longer to fully charge or not do it at all ? Would the higher output simply achieve the required charge quicker or would it damage the batteries ?
Hi Spade, do you have a on board charger that operates when the MH is plugged into 240v say in van park, if so, just plug into your power at home, having first turned all other appliances off. problem solved, the other option is to put up a solar panel with appropriate regulator and let the sun do it for you. Will give you some options for freedom camping as well to boot.
You could buy a C-tek trickle charger. When you plug into 240, plug this in and hook up to your batteries for charging. As its trickle charging you will only get what you need and the gauge on it tells you what its up to.
Mine cost about $80 at a battery place.
You can also get them wired in so any time you plug into power it automatically starts charging.
The CTek charger at that price is 5 Amp, is 5 Amp sufficient for 210 AH of batteries ?
G'Day Spade, I have a similar set up to you, 2 x 75 AH batteries to power the MH.
I bought a 15 amp CTek charger about 12 months ago, it's a good charger, does what I require of it and small enough to carry with me in case of emergency.
As a matter of interest, you make no mention of solar panels, a lot of MH's have them taking care of battery charge when the vehicle is not in use.
I think mine was maybe an 8amp, I know their sizings were different to what I first saw advertised.. Its under my bed in the van. If I remember in the morning will have a look when I make the bed up.
My motorhome has two 105 AH deep cycle batteries in parallel that provide the power independent of the vehicles starting battery, I need to buy a new battery charger to keep them in a state of charge at home during long periods when I don't use the vehicle. I have been looking around and don't know if I should buy a model that produces 5, 10, 15, 20, or 40 amp output or whether it wouldn't make any difference. Would the lesser output just take longer to fully charge or not do it at all ? Would the higher output simply achieve the required charge quicker or would it damage the batteries ?
If you are going to buy a charger then get a decent size unit. With 210 amps to cater for a small trickle is usless when the batteries are down & will do more harm than good
As for when at home a large charger will not damage the batteries; Reguardless of size of charger & charge state of the batteries the batteries will ALWAYS determine the amount of charge that they will accept.If you can afford a bigger unit then go for it as the benifits will be gained when you do have a low battery situation.
EG, if batteries are at 50%, Then 105amps @ 20amp per/hr =5hrs.(105 @ 5amps =25hrs) BUT the way it works is that you really have to provide 1.5amps minium for every 1 amp you use to recharge. therefore your 105 becomes 155amps @ 20amp=7.5hrs
This is just a basic example, you choose.
JC.
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Be your self; there's no body better qualified ! "I came into this world with nothing , I still have most of it"
I have a 120 W solar panel but my batteries have still gone flat
120watts of solar setup correct will give you up to 8amps of charge, if you are not drawing from barreries then there is some thing wrong with the system.
JC.
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Be your self; there's no body better qualified ! "I came into this world with nothing , I still have most of it"
Another one for CTec brilliant for leaving on all the time 240 is available. Mine is never turned off. Can't remember the size of it and its in the shed ad I'm not!
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Cheers Jeff
Ticking off the bucket list before we kick it!
200 TTD with Evernew 22'6" and 40+ years in the oil & gas industry, now retired. CMCA Member.
Another one for CTec brilliant for leaving on all the time 240 is available. Mine is never turned off. Can't remember the size of it and its in the shed ad I'm not!
Most modern units are multistage, therefore can be left on.
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Be your self; there's no body better qualified ! "I came into this world with nothing , I still have most of it"
When I installed the battery system in our van I used a Trojan wet cell Deep cycle battery and a C-Tek 25amp charger, with this we could stay out for a couple of nights then head for a caravan park for a charge up, the charger had the capacity to have the battery charged over night ready for the next day. (The charger was fixed in the van and plugged in at all time so when the van was connected to power the charger came in to operation).
I then installed 150watt solar panels on the top and installed a 30amp regulator.
The whole system worked well and the van while at home, the charger was left on in the shed as the solar was covered.
What type and size regulator do you have?
If the batteries are bulging it seems that something is not working or not installed correctly and they are being overcharged, they other side is that you have been unfortunate and have received 3 batteries that have had cells collapse which has caused the bulging and now will not hold the charge.
How old are the Batteries?
-- Edited by patrolst on Monday 26th of August 2013 09:02:06 AM
-- Edited by patrolst on Monday 26th of August 2013 03:58:41 PM
I have a 120 W solar panel but my batteries have still gone flat
You must be drawing more power from the batteries then the solar panels can generate then. Otherwise with 120 Watt panel it should keep your battery pretty well topped up, I only use a 20 Watt panel and it works fine. Is the battery itself ok? How old is it?
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Stewart www.vkportable.com.au www.forums.vkportable.com.au
This whole battery thing is just one long sorry saga, I have not been reluctant to consult professionals or spend money following their advice to get the whole bloody thing set up correctly.
When I bought the motorhome it had one 105AH battery which was charged by either the cars alternator or an onboard 7 amp 240V battery charger. I thought it would be a good idea to have twice the capacity/reserve so got the dealer to instal another 105AH battery in parallel, he even made sure it was exactly the same make and model as the existing one but he advised me to get a larger charger so I went to a local Battery World outlet who advertised that they also did solar installations. I got them to instal one 130 watt solar panel and a 15 or 20 watt charger which I thought would be perfect to leave on trickle charge for the times when the rig was unused for long periods.
Some time after that I found that the batteries were flat so went back to Battery World, they found one battery was bulging and buggered and a 35A fuse was also blown, they replaced the battery and fuse and off I went confident in my naive ignorance.
Some time after that I found that the batteries were flat again and the charger wasn't working so I looked on eBay and found a 40 amp charger at a good price, bought it, installed it. Some time after that I found that the batteries were flat again so took them out, they were both bulged out at the sides and dry as the Sahara Desert and incapable of being recharged according to a borrowed charger that diagnoses the condition of batteries.
I have bought two new batteries now and installed them but have absolutely no confidence that the 40 amp trickle charger or the 130 watt solar panel will either keep them charged or not boil them dry again and destroy them hence my original question regarding the size of the charger
I have been thinking about going to Springers Solar here in Brisbane for advice and to get them to check the previous installation
Where are you in Brisbane?
Another good company is "Solar Express" in Caboolture I have used them to purchase gear regularly to do my install and upgrades, Ian Ralph is the person I have dealt with and he is very helpful and gives good advise.
I am on the south side, Springers at Tingalpa is a reasonably short drive, the more I think about it the more I am persuaded to go see them because it may be a good idea to get them to check the whole thing out and also instal some device that will tell me at a glance the state of charge
In the old bus I had AGM batteries and used portable solar and used a ctek 25A charger and lived full time on the road and hardly ever needed to plug into power.
Make sure you have a good solar regulator and it is set to the batteries you purchase. Most suppliers don't know how to set a regulator and just instal and hope all is OK.
Check the voltage at the panels if you can or at a connection inside between the panels and the regulator and if you can after the regulator.
Check the current being produced by using a clamp meter and check that with the regulator both before and after the regulator.
Make sure your cables are as large as possible, they cant be too heavy but slightly under will cost you lots of power.
Check you charger and solar panels for cutoff etc. Make sure they don't push you batteries past their max allowed voltage.
To check you solar setup push the batteries up high with a charger and then let them finish with the regulator noting the voltages that it changes from boost to absorb to float. All lead acid batteries have these levels and they should be documented. If this info is not available don't buy the batteries.
Whilst checking your charge rate changes check the amp going in for each stage. This can only be observed when it charges eg example boost 10A absorb 5A float .2A.
Many installers will install to get them the most money so do your research early and then when you go into their store be aware of the wire size you need and also what sort of batteries you want and need.
I am not a techie so this is just what I have observed in my time of travelling and the experimenting that I have done with my buses.
Regards
Brian
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11 Mtr house Boat based at Mannum hoping to travel up the Murray as far as I can get then drift back again
I am on the south side, Springers at Tingalpa is a reasonably short drive, the more I think about it the more I am persuaded to go see them because it may be a good idea to get them to check the whole thing out and also instal some device that will tell me at a glance the state of charge
Definitely a good idea to have it check! Springers is a reputable company too!
I have been thinking about going to Springers Solar here in Brisbane for advice and to get them to check the previous installation
Where are you in Brisbane?
Another good company is "Solar Express" in Caboolture I have used them to purchase gear regularly to do my install and upgrades, Ian Ralph is the person I have dealt with and he is very helpful and gives good advise.
I have used Springers who are also very helpful.
Another good company is "Solar Express" in Caboolture,,, agree also.
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Why is it so? Professor Julius Sumner Miller, a profound influence on my life, who explained science to us on TV in the 60's.
