Kimberley camper solar

Thanks Allan, I will try and follow the wiring,Kimberley don't use a DC dc charger but it would be a good idea .
peter r

If there is no charger then OK to simply connect to the Anderson plug Peter. If you have a multimeter then it may be prudent to measure the voltage at the battery terminals before and after connecting the solar panel (in full sunlight) to be reassured that it is providing charge. There should be a small rise in voltage when the panel is connected.

Allan,

I apply a maintenance charge to the camper batteries by this method and I have installed a Ctek dc-dc charger in the camper.

To "fool" the dc charger into thinking it's receiving 12v power from the alternator, I need to switch the mode on the AC charger to supply mode otherwise this charger will not recognise a valid connection.

Otherwise the method works a treat with the dc charger supplying bulk charging if required, then changjng to maintenance mode to maintain a float charge.

Yes Bill, but that is with an AC charger in "supply" mode. We were discussing using a solar panel which, depending on its rating may not be capable of driving via a dc-dc charger. And Peter has said that the camper does not have a dc-dc charger fitted.

Yes, Gotcha. I guess I was slightly out of the context of the post.
My on-board charger also takes solar input so I don't need to connect via the cable input.

Hi Peter (Battery Value), What is your view of the small (100mA) chargers such as the Jayco MB-3501 for simply maintaining (not recharging) both flooded and AGM batteries?

I have a 40w panel with regulator. Exhide AGM 6x35ah the batteries may not be fully charged when it goes into storage as it will be stored on the same day as we use the camper ,that means the solar will need to charge the batteries untill i can get back to use it again. there is no 240v available . i think it will work .
thanks peter r

Allan,

sorry I don't have one of these in my tool box and can't find their specs online either.
But if 100mA is all there is, then this is indeed only for maintaining full charge - as long as the battery bank is smaller than 100~150Ah.

And because it's a maintenance charger which stays connected to the battery for a long period of time, there'd better be temperature compensation of the float charging voltage.

It's also recommended to periodically discharge the battery to about 70~80% SOC, and recharge it with a multistage charger capable of supplying a beefy current.

There are good MPPT solar regulators to be had, for surprisingly little money which combine all these with proper multistage charging. And the charging current can reach up to 10 amps.

cheers, Peter

Thanks Peter, The product I was referring to was the Jaycar MB-3501 or similar, 15v open circuit, 120mA max, no regulator.

I used one for a while and the battery never got over 12.8 volts. Now the Troopy electrics are too complex for this and anyway it gets a run every few days.

no worries Allan,

just had a look at it online, and I don't recommend it.

Use it on a 100Ah AGM battery and it'll wreck it half way down its normal life span, or even earlier.

Reason for this is that most of the time, this unit outputs less than the specced max charging current.
And the moment you drive current through a VRLA battery, which is less than the steady state current necessary to maintain the float voltage of 13.6~13.8V, you actually discharge the negative electrodes - not kidding.

So you end up with a chronically undercharged battery and massive sulphation in the negative electrodes.

Your observation of the low 12.8V 'charging voltage' from this worthless piece of c... confirms this.

cheers, Peter

Thanks Peter, There really is more to battery management than most people realise, including myself.

I didn't know that the Kombi had a battery. I thought they were spring-wound. LOL

But perhaps Peter of Battery Value might comment on leaving a battery stand for seven months without maintenance charge?

A battery sitting there for 7 months without exercising it, or at least receiving periodic topups, or float charging, is bad news.

If there's no better way of looking after it when stored, then it needs to be cycled a few times to make it develop its full capacity again (a small fraction of it will be gone for good, just by letting it sit for that long, no matter what you do with it afterwards).

cheers, Peter

Hey allan b, the spring broke so I installed not one, but two batteries. lol Interesting comment from peter though. so how often then would you float the batteries and I assume you are talking battery charger?
Also, if you only need to float it every now and then, then wouldn't this be better than pumping power into it all the time with a solar panel?
shane c5

YES the panel could be open to lowlife ,i will sit it up a pole .thats the best i can do about that ,if i had to take the batteries out i would bring the camper home ,but that takes away from the easy use of my camper at the site or go on the road a lot more .
thanks peter r