[PHILIP HARDY]

Hi guys looking for some advice, I now run a two man set up with a 110amp leasure battery which is charged by the sprint controller-charger directly from the van battery, I have always used a leasure battery for this, as in the early days it was a run flat and recharge overnight system and it was widely regarded that leasure batterys were the best for this type of work,we now have moved on to direct charge from the van engine. My battery appears to be at the end of its tether (over two years old), so the question is
1) Do I stick with replacing it with another leasure battery
2) Is a reguler high ampage van battery more suitable to the frequent trickle charge that it now receives, resulting in longer life.

If anyone has any experiance in this I would appreciate hearing.
Thanks Phil

[Don Kee]

Leisure ure battery for definite

Stick with 110ah and you'll be fine, obviously the rate of charge will depend on how long the van is on for (which usually correlates with how much you travel) so it may be an idea to have an inline volt metre to keep track on the batteries state of charge and give it a bench charge whenever it needs it


If it helps, I have a 2man set up, split charger fitted 3/4 months ago and I've not bench charged it yet (although I might over this weekend as we've done some pretty compact stuff this past week and so have discharged the battery a fair bit)

[Spruce]

Its not recommended to use a starter battery or leisure battery below 50% of its capacity.  This is why I bench charge mine every second night and don't rely on the van's split charge relay. We don't do enough mileage to replace the charge we use during the day.

Our Shurflo pumps draw about 4.5amps per hour using a controller at a flow of about 2lpm through the jets. You need to identify how many hours your pumps are running for to understand how often you should charge your battery.

For our residential customers we estimate that we pump water for approx 50% of the time we are working on a compact round. So if we are out for 6 hours then we believe that 3 hours are actually pumping water cleaning windows.  So each pump will draw about 13.5amps from the battery. So with 2 pumps and a fully charged 110 amph leisure battery then you would draw 27 amps and that would leave you 83 amps. On our drive home which might take 20 minutes all the alternator will put back into the battery is a about 2 amps leaving us with 85 amps.

Do the same the following day. The alternator will add 4 amps there and back and you will draw another 27 amps during the day. So after you have arrived back home the battery will have 60 amps left.

Unfortunately its not quite as easy as that because a battery with a low charge will accept a higher rate of charge. As it get fuller, the battery will accept a smaller and smaller charge. So on the second day the battery may have received a couple more amps on the same journey that it did the previous day. But even if its 6 or 8 amps you battery will still be a little over 50% charged.

Now, if you leave the battery in a low state of charge, eventually the capacity of the battery reduces due to sulphation of the battery plates. This is why Numax say that we abuse our batteries by the nature of the work we do, so they refuse warranty on batteries used by window cleaners. They say that we have done well to get 12 months useage out of one.
But with proper charging we have had 4 years from a 110 amph Numax, 5 years from an 85 amph Numax and 6 years from another 85amph Numax.

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[PHILIP HARDY]

Thanks guys. I have had mine on a split charge for around 18 months and NEVER bench charged it but my mileage is pretty high and I rarely have more than 30 minutes in one spot, I would guess that I have depleted it slowly and when it has recently started playing up (just had to leave the engine running whilst working which also happened a couple of days over the winter when I was travelling in the dark with lights/wipers etc on), is because its run low,I will give it a bench charge over the weekend and put it onto a reguler cycle after and hopefully will get plenty of more life out of it,
Good info cheers.