Battery Charging, 3 or 4 Step? Is there a great difference?

The Meerkat

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Help Please!!

As the outdoor season vastly approaches us, I was looking at redoing my “lectrics” on they old Eccles machine, I would be looking to install an 18 amp charger and am still undecided whether it is best to go for a 3 stage or a 4 stage, as there is a Credit crunch on at the moment any savings I could make would be most welcoming and any further knowledge would be most appreciated?

Is the 4 stage just a gimmick to squeeze more £ out of people or would it be better to take the hit, pay a little extra for something that would benefit me in the long run

I have had a look at few on the web, and have came across a few at Aldis, a company known as Muvonics/Amperor in Hull and as ever Maplin

Any guidance is appreciated

:eek::eek:
 
All multi stage chargers in motorhomes are a gimmick in the sense that they are the wrong tool for the job. Providing that your alternator supplied split chare system is in good order, when ever you arrive on site your leisure batteries will be (as near as makes no difference) fully charged. Therefore your 240V supply provides the power that you use, and at best only trickle charges your battery.

It is also worth remembering that if used whilst occupying the motorhome a multi stage charger will supply a system voltage above a normally safe limit, this at best reduces the life of items like bulbs but can cause immediate failure of voltage sensitive components e.g. TV's Computors etc.

Lots of claims are made about how much these chargers extend the life of the batteries, quite how they do this when in normal use they dont even charge the batteries, I fail to see.

If money is tight and you wish to sort out your electrics start by ensuring you have a good split charge relay, the cables are heavy enough so as not to induce a significant voltage drop, this is an area were original fitment is often severly lacking, and all the connections are clean and tight. If you do use EHU's check you have a decent power supply which is adequately rated for your needs.

Getting and keeping a simple system up to scratch need not cost a lot and will probably out perform a poorly maintained system full of expensive components that don't achieve a lot.
 
Amperes, Electrons and Voltage Oh My!

Geoff is correct that while rolling on to your next overnight spot your motor generator should re-fill the starter battery and then the house batteries at a rate of generally 30-50 Amps... But remember that's per-Hour. So number 1; Your starter battery better be up to the task or it will garner a majority percentage of that amperage flow and starve out your house banks!, number 2; I said "per-Hour", so if you used say 2 or 3 hours on the computer + a few hours of lamps and took a shower all of this adds up to about 340 watts used (340/12 = ca. 29 Amperes) therefore you will need to run on down the road for at least 1 hour after the generator (alternator) has finished getting the starter battery ready for the next big jolt! By the way, your 18 amp charger will do all this in just a couple of hours on the grid.

Deep cycle Leisure batteries, at least the respectable ones I.E. Master Volt, DETA and Excide, are getting very expensive. These IUoU Battery chargers are intelligent capacity sensing electrical devices capable of throwing electrons as fast as possible into the lead-acid mix while keeping close watch over that progress, maximizing the charge input progressively while keeping the acid from bubbling right out of the battery. These chargers also do something special which is called Hyper Charging (the 4th stage) which blows the calcium (Calcification) off the lead plates keeping them clear to accept all the electrons that flow to and from them. It keeps these batteries young so to speak and maximizes their long but limited cycles. These 4 stage chargers are only cost effective when maximizing the life out of these costly batteries. You can set up with a trickle charger and a couple of starter batteries but I believe that in the long run you will equalize the cost of a first class battery/charger system in just a couple of years vs trading out used up starter batteries.

What ever you decide, get a charger that has a charging capacity (Amps) that equals at least 30% of your battery bank potential. (A battery's potential is 50% of the rated amp/hour capacity stated on the battery and it's the point where the battery's go below 12 volts and begin damaging themselves.) I.E. 100Ah @ 1 Amp/Hr = (50Ah potential x 30%) = 15 Ah charger. It will recover its charge in three hours.

Happy Electrons!
 
Providing that your alternator supplied split chare system is in good order, when ever you arrive on site your leisure batteries will be (as near as makes no difference) fully charged.
Click to expand...

This sweeping assurance ignores the fact that the way an engine battery is used is entirely different to the way a leisure battery is. The alternator is designed to replace the 5 Amp-minutes of power used to start the engine and also supply all other loads while driving. It does the job very well.

Consider a motorhome with say 200Ah of installed battery run down to 40%. This needs 120Ah to be replaced so say at least 150Ah to be input.
Typical alternator might put out 40A initially but this drops very rapidly and after 30 minutes of driving is likely to be putting only 20 amps into the battery - and this will continue to drop as the voltage rises. To replace 120Ah in any realistic drive is just not going to happen. It may happen eventually but most of us have better things to do that drive around the block to charge the battery up.
Get a reasonable 3-stage charger and do the job properly.
 
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