Part 8 - A new Leisure Battery

From Part 6 

This is an experiment - I've tried a brand new highly esteemed 110AH battery from Banner. Now I'm running with a five year old 44AH starter battery from Alphaline!
We shall see what we shall see.

Well we saw! The wee 44AH battery may have been OK, but it was a worry. Due to unforeseen circumstances we had to take a two week trip. This was mostly parked up with no hookup and not a lot of engine running time to keep the battery topped up.
Now, the battery never failed, and it never even gave the impression that it was about to. But we had to stay in the vehicle most of the time, and had to keep charging a laptop, a tablet and two phones. The fridge was on all of the time and there would have been very little from the solar panel

We have never been particularly careful when using power, but because we were aware of the limitations of the battery we found ourselves switching off lights at every opportunity.

So we gave in and bought another leisure battery. This time it was a Varta LFD90 from Battery Megastore.

We were actually living in the van at the time and had little time to research batteries but I found this site which did sway me.

We got around four years from the previous Banner battery which works out at about £30 per year.  That is not bad really for the amount of work it has to do.

An occasional motorhome user using hookups or with a roof full of solar panels may not have noticed it was down to 25% of its original capacity (although he may struggle if he were where I am as I write this - in a municipal car park and the roof covered in snow)

We find we are using the lights after around 4pm and almost continuous until around midnight (with a 1-2 hour break for a meal) so that is about 6.5 hours. We also are charging up two phones, and ipad and a laptop every day. And of course the fridge re-igniter is on.

	Time	Current	Amp Hrs.
Spots	2.5	0.59	1.48
Roof Lights	4.5	0.42	1.89
Fridge	24	0.08	1.92
Phones			1.2
Ipad			1.8
Laptop			3.5
TOTAL			11.79

So even with the bigger Varta Battery we'd take 13% of the capacity per day.  Four days would be about 50% of the battery's capacity.

But with a bit of forethought we can minimise that. We can't do much about the fridge and lights and we can't do much about the actual usage of the technology.
But we can use the engine and alternator to ease the load. The alternator will charge at about 10Amps in addition to charging up the laptop and phones etc at the same time. So we can recover ALL of the light and fridge load in under 30min with the engine running.

We can also use the time with the engine running to charge up the phones and laptop, at least 50%.

Our little solar panel will contribute a bit - maybe 1-2AH.

That takes the load charge from the battery down to only about 4%. This should be no problem for the battery.

This is an unusual situation for us - but in our little van we are warm and cosy and comfortable despite the outside temperature being below zero.

In the summer, with less time in the vehicle and less time on phones and laptops, and more from the panel we will not need the to use the engine for at least a week.

ROLL ON SUMMER

Addenda
The little Alphaline battery was put into a Vauxhall Agila whose own battery was struggling.  The simple battery preservation technique I described in Part 4 saved the price of a new battery.

A few changes to take advantage of the wee solar panel are called for.