Battery charger question

qwertyphobia1

hi

Looking to find the right battery charger for my leisure battery. It's 115AH. I am doing some longterm travel. At the moment my leisure battery is being topped up by solar panels and from the altenator when driving. Have kept my mains and 12Volt totaly seperate, not sure if this is usualy the case. My invertor stops working when the battery goes below 80%(is this the case with all invertors?)

So I am looking at a battery charger to top it up every now and again, so the invertor will keep working. Don't have that much of a drain on power mainly just lights and on the invertor charging up laptop and AA batterys. Doing a fair bit of wild camping, but check into camp sities every now and then. Campsites ofen have electricity on a lower amperage would this be a problem for some battery chargers? Was thinking about this one http://www.ringautomotive.co.uk/product_detail.asp?prod=1372

Anyone have any experience of that one or other chargers running from campsite power?

Have come across a few 750 watt portable generators here in spain for 100 euros. But that seams like a long way around to sort out a small problem.

thanks

yammagamma

hi. 115AH is not that much if you are planning on doing a good bit of travel with wild camping,but some more detail might be a help. what wattage/type solar panels have you.what is your split charge setup?ie alt output. are you running it through a alt to 4 step battery charger or just using relays, your lights what is total wattage are they leds ? your inverter what wattage is it what is it efficiency ?do you fully disconnect inverter from battery source when not in use , might be better to run laptop straight from battery depending on laptop voltage or look for a step up regulator if its highter then 12ish, also your battery is it gel/sealed or open wet or sealed .has it calcium in it ? all these would be a factor on best battery charger for your setup.the quicker battery chargers will have a higher voltage but this will boil water off battery also read that calcium in batteries needs even a higher voltage but this might effect all other 12 volt electronics in camper,do you want a battery charger built into your system or a portable 1 ?a good all around charger range is ctek or sterling i have used

qwertyphobia1

thanks got sorted

paddyp

Ring charger is max 16A so it will only be drawing 16 x 14.4 = 230W you can add a bit more for inefficiency in the charger so say 300W worst case. This should be no problem at any campsite.

"My invertor stops working when the battery goes below 80%(is this the case with all invertors?"

The invertor has a voltage cutoff point, the lower the input voltage means the inverter has to draw more current to produce the same output and the duty cycle of the transistors changes .This leads to heat and stress on the switching components. The cutoff is to prevent failure.

How are you determining that the battery is below 80%? Its not simply a case of multiplying amps by hours or measuring the terminal voltage. High currents really reduce the amount of amp hours you'll get from the battery. Add to that the fact that your alternator will probably never fully charge the battery.

Also the terminal voltage that indicates 80% charge at 50A is much lower than the terminal voltage that indicates 80% charge at 10A. Terminal voltage will vary according to the construction of the battery so the number on a zig unit dial for example are meaningless.