Charging via Generator

I may just jump on the back of this Banjo if you dont mind, get two similar questions done together. I am building up a CT when I get home from overseas and have a short timeframe to do it in. How many south pacific peso's for a Battery setup in the CT with charger and all the rest that goes with it?. Would like to have dual batteries in the truck but no room under the bonnet. I have been toying with the idea of using one of those outback chargers as mentioned in January's edition of 4WD monthly. The cost of that and a battery would comeout at around a grand.

Any suggestions

cheers

Jeepster

Yes you are right. Worse still the voltage output is not consistent and you need a different voltage for charging for wet lead acid and AGM batteries. In my opinion, depending on what current your battery can take purchase as high a 3 (4 even better) stage battery charger with Wet lead acid/AGM switch as you can and you should be right.

Despite what others may say if you shop around you can get 3 stage chargers now from under $200. I think my 15amp cost $178 from some marine place.

If your 4amp charger is auto and goes into float charge when the battery is charged then that's the go.
I believe that there is no regulator on the batt charge part of a genny so there is always the risk of overcharge/cooking of a battery.

Hi Banjo,
Firstly I would go with the Yamaha 1000 w gennie, as it shuts down to 47 DB under low demand, and catch up with Roachie about the charger as he has a 3 stage charger setup which charges to 80% fast and then slows down so you dont need gennie on for as long.
Last year at new year we were camped for several days on the river and roachies yam genn was running 5 fridges and 3 batt chargers and it was still cutting in and out of low demand, the system works a treat, and at 47 DB you can sleep right next to it during the arvo when a snooze is required !!

Merry Xmas Pesty

I've got the Kipor, a 15 amp smart charger, a 40amp switch mode power supply and solar gear.

Solar gear (one panel) and a few batteries get me by for at least a week for a 60 litre fridge and freezer plus lights, shower, etc.

Use the gen and chargers after that.

Even though I have a 3 stage charger you don't really need one, reality is that the main cause of battery failure is under charging so the key thing is to get it above a certain voltage asap. Ok yes I know the smart chargers fully charge a battery safely and may extend life. However it's debatable. My 40 amp (max 15 volt) power supply cost about $250 off ebay. Ran it off the Kipor along with the 15 amp smart charger and gave the 4 batteries a charge over about 5 hours after they got down to about 11 volts. Not ideal to go to this voltage but I was testing how long the setup would last.

So what I'm saying is if you don't have the $$ for a large smart charge, go for a switch mode power supply. Your 4 or 8 amp units are simply way to small. Also remember that the batteries will only accept what they can resistance will limit the current draw if you have the voltage set right.

Hello Banjo 1,
I've got a 1kva Honda and a 15Amp 3-Stage charger. (Black bugger, can't remember the make)
They work really well together for the application you are outlining.
Much better than the 12v outlet on the Honda.

Geoff.

Having bitched a bit on this thread I suppose I should give you a considered reply - something I rarely do these days on this forum due to the editing policy of the owners.

The easiest and cheapest way is to use the 12V charging output of the gen. this has a couple of issues:

1 - as the battery takes up a little charge it's internal impedance will rise and cause the current accepted to reduce. The numbers here depend upon the capacity of your battery, it's chemistry and it's state of discharge - at a guess after about 30 to 60 minutes of running your gen will only be pushing around 2 to 4 amps into the battery.

2 - I can't speak for the Honda or other good quality gens but my $98 GMC is pretty rough and ready on the battery charging side - the "12 volt" output has an unsmoothed DC output of 22V with 100Hz (return to zero) ripple. This, of course, drops to around 17/18V smooth when a battery is connected. Most large (> 30Ah) batteries will not be too upset by this voltage however I would carefully monitor the time and current flow into the battery to ensure it doesn't suffer excessive heating - it will be OK for a few hours (depends on capacity and chemistry) but watch it after that. The Honda is probably better but my guess is not by a lot??? NB. You will not "cook" a battery providing you use a little common sense – that is largely an Explore Oz "expert" opinion – they are robust devices.

My preferred option is to use a half-way-decent battery charger from Jaycar, part number MB-3612 which is a switch mode 12V 6A/12A (switchable) semi intelligent charger - however I have my doubts if the designer was - it tends to put 110V between earth and battery neg. so watch how you handle it and keep it away from children. I really must get around to telling Jaycar to take it off the market (again!) so buy one fast 'cause it's damn good value if it doesn't kill you :)

Mike Harding

mike_harding@fastmail.fm

Thanks a lot folks - plenty of contributions to evaluate there ! For the record, I see the 1KVA gennies as: Honda - $1440 in SA (with rebate) - quality - the leader possibly: Yamaha - $1340 in SA - equal to Honda: Kipor - $940 in SA possibly, $730 via eBay - specs match the others but quality and BACKUP (cautions have been expressed on this forum) are the questions, should the proverbial hit the spinning blades. Hon/Yam have 2 years Warranty - Kipor only 1. I'm likely to go Yamaha - they are sophisticated, quiet and reliable for the longer term it seems.... and the cost is lower, even without an expiring factory rebate ! As for charging, switchable smart seems the consensus ! THANKS ALL for the input - power to the forumites !

I have a 650w Yamaha genie that does not have a 12v outlet and to charge up my Trojan DSB I have been using a model PTC75-b battery charger purchased from SCA. It states that is 'Fully Automatic' it has a current selection of 2,6 & 12a. It also has a 75a engine start facility.
Is this charger suitable for charging my DSB?
Thank you.
ps. As the charger runs the amps drop. This would not be a 3 stage charger?????

Like you I have also been looking into power supplies recently and found a lot of good info at this sight www.caravanandmotorhomebooks.com/articles/index.htm. The other alternative to a generator if you your main purpose is battery charging would Christies alternator charger, www.christieengineering.com.au/

Hi everyone, I have a closely related question (reposted due the crash).

I am wondering about using a Jaycar 20A solar charger (Cat. MP-3129) as a general-purpose battery charger. It is $170 but very well-specified, with LCD display, pulse-width mod, 3-stage with programmable equalisation and low-voltage load cutout to name a few tricks. The only thing it doesn't provide is the actual charging energy.

Obviously it is designed to manage and charge your battery from a solar panel, but it strikes me that it wouldn't know (or care) whether the energy was coming from a solar panel or a cheap genny or a rough-as-guts battery charger or power supply. Presumably as long as you provide it with somewhere between 14-26V DC it will regulate it as required to charge the battery.

So it strikes me that it would make a good, set-and-forget, on-board charger/controller that will protect the batteries from being flattened and would then let you hook up any old source of power for recharging - whether it's a genny in the bush or a power supply at home.

FWIW I have a pair of Exide 6V 175Ah telecom wet cells that will only get used occasionally. Charging would come from a $98 GMC genny and/or a SuperCheap 'automatic' 2/6/12/75A charger/starter (the same model as Ray's). The batteries don't get used all that often so I am reluctant to trust them to the SuperCheap charger permanently (there's 'automatic' and there's 'SuperCheap automatic'), but I figure with the Jaycar controller I could leave the SC charger on full power for charging and maintenance, and I would just need to turn off the charger and use the batteries once in a while to cycle them and make them feel loved. The Jaycar unit would protect them from over-discharge.

Any thoughts or comments? Have I overlooked anything or is my logic sound?