motorhome charger

[wildcamping2013]

Hi all

am after some advice I have a swift gazelle Motorhome and I have two 250ah leisure batteries the only problem is when I use the EHU at home or campsites just to top the batteries up its not really doing a lot as its taking for ever to charge. Can anyone recommend what unit I can replace it with that can cope with charging 500ah

the one I have at the moment is very old and its only a 12amp charger and getting very hot

Many thanks

Paul

[Keithl]

Hi Paul and welcome to the forum,

 

You are going to need quite a large charger to cope with 500 Ah of battery!

 

Something like a CTEK MXS 25EC which says is suitable for 40 to 500 Ah of battery. It will not be cheap but WILL be suitable for the job!

 

http://www.ctek.com/gb/en/chargers/MXS%2025EC

 

Or have a look at others in the CTEK range for one suitable for your size of battery.

 

IMO they stand head and shoulders above any other mains charger.

 

Keith.

 

Edit to add: The MXS 25EC costs £280 at Tayna batteries

 

https://www.tayna.co.uk/CTEK-MXS-25EC-Extended-Battery-Charger-MXS-25000-Extended-P7797.html

 

Or an XS 25000 will do the job and appears to be discontinued so on clearance for £180 here:

 

http://www.demon-tweeks.co.uk/motorcycle/battery-chargers-conditioners/ctek-clearance-multi-xs-25000-battery-charger

[747]

Remove one battery, fit a 30 Amp charger and then fit Solar panel(s) also.

 

You will then be able to wildcamp for most of the year (unless you use Microwaves, Hairdryers etc. If that is the case then use sites instead. We never have a hookup with 200 Ah of Batteries and a 100 Watt solar panel (with a 90 Watt one in reserve in the garage for when the Sun don't shine for days).

[aandncaravan]

The usual rule is a charger minimum of 1/10th the Battery bank amp hours converted to Amps, so 500Ah dived by 10 = 50Amp minimum charger power, preferably bigger?

 

If you don't have a charger with enough 'oomph' not only will the batteries take forever to charge, but they may rarely reach full charge, leading to Sulphation and battery degradation. This makes them harder to charger so they are likely to be less charged, Sulphate more, etc.

 

However, just as important is that your battery bank of nearly 600Ah ( 500Ah + 90Ah of Starter battery) is a massive load for any Alternator?

 

I would suggest that the battery bank is too big for Solar, unless you have a huge Solar array, for the same reasons stated above?

 

The reality is that although you have a 500Ah battery bank, it probably gets no more than 70 - 80% charged, at best. If you reduce the bank size it will charge more fully, possibly giving you more power in real terms with longer battery life.

 

 

747's idea is a good one.

 

 

 

 

[wildcamping2013]

Hi

Thanks for the comments, i have noticed that i don't get as long as i thought i would out off the 500 ah batteries so am guessing now you have said about 500ah being too big if i remove one and just have the 250ah i should be better off with power

if i was to get a solar panel(s) and a ctek charger would i t do any damage if they was both connected? and could i still use the batteries while the ctek charger was on?

many thanks

Paul

[KeithM]

wildcamping2013 - 2016-08-07 11:16 PM

 

Snip...................

if i was to get a solar panel(s) and a ctek charger would i t do any damage if they was both connected? and could i still use the batteries while the ctek charger was on?

many thanks

Paul

 

In order, no and yes.

 

If you are using equipment on-board when the solar or C-tek are working (ON), then part of the output from the solar or C-Tek would supply the equipment and possibly charge the batteries as well, depends on output of solar or the C-tek.

 

Example: Not actual figures just as a guide.

 

Solar or C-tek are supplying 10 amps, there is 3 amps of equipment ON then the batteries will still get 7 amps.

 

Very basic, there are lots of ifs buts and wherefores but gives a guide. ;-)

[aandncaravan]

No problems at all with having a Solar regulator charging the batteries alongside a Motorhome battery charger and still drawing power.

 

However, can we go against the general advice that often says to fit a Car based CTEK battery charger (which most of the models are) and suggest you fit a proper Motorhome habitation charger?

 

The few Leisure specific CTEK units are incredibly expensive with few, if any, advantages over the chargers fitted as standard in Motorhomes.

We would suggest you avoid a CTEK and fit 2 x 18A Amperor charger units, at around £75 each, to give you 36a/360Ah capability? Try Amazon.

 

However, that battery bank of 250Ah habitation + 90ah starter battery is still a lot for the Alternator, but you can reduce the impact by using 12.3v as your minimum discharge level.

 

If the battery drops below 12.1v then we would suggest you isolate it by removing the Battery leads, then use a Car battery charger to raise the voltage for a day, before connecting it back up and letting the Motorhome chargers take over.

A Car battery charger has built in shutdown/overload protection so is designed to handle bringing up a battery from very low volts better than a Motorhome charger, which will often just Pop.

 

If the load on a charger battery charger gets hard going it, it will shutdown to protect itself.

 

 

[wildcamping2013]

Hi all

Just a update due to me wanting to keep the 500ah batteries i have now today fitted 200w solar panel and a 30A MPPT controller

so all i need now is to replace the old 12amp on board charger for something better for when am on hook up or want to top the batteries up at home

Paul

[aandncaravan]

Won't the Solar output be fewer amps than the old 12amp charger?

At best, on a sunny day in July you might only get 10amps? By October that might be around 8amps ?