Cavernous leisure batteryage!

[ed_crouch]

Hi all,

I'm going to be replacing the knackered and tiny leisure battery in Otto soon.

We'll be going away for a week in August in the old bus, off hookup, and I plan to have a 100W PV system in by then, which ought to deliver something like half our power requirements.

I've calculated that I'll want something like 220Ah of leisure battery to last that sort of time without hookup, even with solar power.

Crikey, thats huge.

I've identified a couple of batteries that'd do the job. One option is a 12V 220Ah job from the likes of Tayna or fleabay, or the other option is a nice pair of Trojan T-105 golf cart batteries, 6V 225Ah each. Trojans are the heaviest at about 55-60kg the pair

Am I bonkers to be considering fitting such a huge battery bank to the van?

We'll be running a propex (if its cool overnight), a couple of lights, charging phones/iPad, water pump for the sink, and maybe some mellow sounds from the stereo whilst we sit around the fire swapping manly stories of "slaying wildebeest and wooing fair maidens" and eating undercooked BBQ meat.

That sort of batteryage will either:

1)go in the porta-potti cupboard (dont like chemical toilets, would rather walk to the campsite bog) to the right of the fridge in the case of the Trojans - they're flooded, non-sealed - dangerous to have inside the van?!? Hydrogen? Acid stink? Thoughts please.
2)go in the offside rear wardrobe bit (Autohomes Kamper)
3) sit behind the front bumper in the now unused spare wheel area - I'll make a suitable cradle to hold them securely.

Does what I'm proposing sound reasonable, or have I lost the plot totally?

Thankyou!

Ed.

[phil_b]

Sounds OTT but depends on your individual power requiremnets and whether you to plan to drive at all, or just park up and not start the engine for a week.

We have similar power usage and always off grid, we have never run out of power but we do tend to do at least short journeys once every couple of days. We have full LED lighting and I wouldn't normally expect to be running our Erber heater overnight in summer, it might be cheaper to buy a thicker duvet

We also want to be self sufficient for longer periods so in the last couple of weeks have fitted a 100w solar panel (actually 20 x 50 semi flexible), very impressed so far. The charge controller displays input and output volts and amps etc so have been monitoring with interest. Even at this time of year peak charging currents have been up to 3.2 amps at over 14v. On overcast days it still charges at around 1amp pretty much from dawn to dusk. In summer I think/hope we will have an abundance of power.

We only have a 90ah leisure battery but still consider that with the panel we will be pretty self sufficinet, the only times it could be a problem is prolonged cloudy weather or in the middle of winter when daylight hours are less. But on those occasions we are unlikley to be stationary for so long.

When we recently replaced the battery we did note that some companies are quoting much higher capacities, 115ah, for batteries of exactly the same size, weight and construction, so there seems to be quite a lot of BS out there. This is not the case with Trojans from what I hear but I dont have the space or funds for those, I also think they may need a specialist charger to get the best from them.

[ed_crouch]

Well, in the end I spent the money on a 200W solar charge system with a MPPT charger, and just bought a boggo 100Ah leisure battery. In August on the south coast (where we're going this summer), we'll be getting something like 60Ah per day of charge given average weather. More if its well nice, less if its pants.

I think I probably did the right thing?

[LeeME3]

We also want to be self sufficient for longer periods so in the last couple of weeks have fitted a 100w solar panel (actually 20 x 50 semi flexible), very impressed so far. The charge controller displays input and output volts and amps etc so have been monitoring with interest. Even at this time of year peak charging currents have been up to 3.2 amps at over 14v. On overcast days it still charges at around 1amp pretty much from dawn to dusk. In summer I think/hope we will have an abundance of power.

Sorry for the thread hijack....any chance of a link to the panel you bought? Sounds exactly what I'm looking for.

[ghost123uk]

Sounds a lot better than mine, 3 Amps in direct summer sun, next to nothing (~200ma) on a cloudy day

[phil_b]

Panel and charge controller from an online company called Renytek, also on Ebay under a different name. Was originally looking for a single 100w from them but they were waiting for new stock, they offered the 2 x 50w at the same price and also upgraded the charge controller, £199 total inc next day delivery. Only thing I didnt like about the panels was the poor sealant around the junction box lid, I cleaned this off and resealed it myself.

Last Saturday, late morning in Snowdonia panels were delivering 4.3amps, so well pleased, rated peak output should be 5.8amps but might not see that in the UK. I have disconnected the Leisure from the split charger since fitting and the batteries are always fully charged within a few hours even after significant evening and morning use of the Erber, lights, pump etc.

Ghost1213.. Have been told keeeping the panels clean makes quite a difference but not had them long enough to tell. Also if your battery is already fully charged the controller will only put out a trickle charge so panels may be ok, try putting an electrical load on them and see if the amps delivered goes up.

[ed_crouch]

Well, at 6pm this evening in sunny north Hampshire I put some load directly on the leisure battery, and the solar charge ammeter went up to 4.2A. Considering the season and the fact that the sun is now quite low in the sky, I'll take that!

In the middle of a sunny August day (!) with a leisure battery weary from the previous evening's revelry, I reckon we should be seeing over 10A...

Ed.