Battery Charger

stirlingb

Guest
Hi everyone
I have a Bessacar E495 and have been informed (following a dealers test) that my battery charger (mains to the 12 volt leasure batteries) is kaput.
Being strapped for cash is there any reason as a temporary measure why I can't source a cheapo battery charger from the local car spares shop for about a tenner, take the fuse out of the existing charger so that there is no possibility of a circuit forming through the old charger and then just connecting the new cheapo charger up to the leasure batteries (I have two in parallel) to charge up (I understand it is approx £200 to change the original charger........Thanks in anticipation of wonderful advice
 
If you buy a cheap charger for £10 and you leave it connected some chargers will overcharge and gas your batteries. Also, it may not also have the capacity to charge two big batteries sufficiently quickly but it may work after a fashion.

If you can afford it, get an electronic smart charger for £40-50 which will switch off the charging current and monitor when the batteries are charged. It will also give you a better charging curve/regime. That could be a more permanent solution and is probably as good as the official dealers part. Dealers sell to a captive market with plenty of disposable income so they can afford to hike up the price of parts to ridiculous levels
 
Using a cheap car charger WILL gas your battery. The other thing to consider is that the chargers fitted as original equipment to many UK touring caravans/motorhomes are really regulated power supplies rather than conventional chargers. They are designed not only to charge the battery but also to provide a smooth and stable 12-volt (nominal) supply to your equipment (lights, pump etc). This dual role inevitably results in some compromise. The result is that the output voltage is regulated at of 13.8 volts. This voltage was chosen because it lies just within the 14.0-volt maximum voltage stipulated by EEC regulations for 12-volt caravan equipment. A dedicated battery charger will put out anything between 14.4v and 15.2v depending on the type.
 
stirlingb said:
Hi everyone
I have a Bessacar E495 and have been informed (following a dealers test) that my battery charger (mains to the 12 volt leasure batteries) is kaput.
Being strapped for cash is there any reason as a temporary measure why I can't source a cheapo battery charger from the local car spares shop for about a tenner, take the fuse out of the existing charger so that there is no possibility of a circuit forming through the old charger and then just connecting the new cheapo charger up to the leasure batteries (I have two in parallel) to charge up (I understand it is approx £200 to change the original charger........Thanks in anticipation of wonderful advice
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Your charger is probably made by Seargent. They offer a fixed price repair (£72.66) service to any of their units. Here is a link for them Product Repair Service - Sargent Electrical Services Ltd.
Better to get the original equipment repaired than to mess about with chargers.
Regards,
Wanderer
 
Thanks for the advice so far guys.....as is usual with motorhomes there seems to be more to it than meets the eye!
 
sparxy said:
The other thing to consider is that the chargers fitted as original equipment to many UK touring caravans/motorhomes are really regulated power supplies rather than conventional chargers.
Click to expand...

A crucial point, that is either missed or mis-understood by users.

Regulated means held to specific voltage regardless of current drawn. In order to properly and fully charge a battery different voltages are required according to state of charge of the battery' the degree of use it has had, and point in the battery lifecycle.

At times one will need substantially more than 14.0 Volts offered available.

Given the, surprisingly high, cost of repair for the original poster's unit, there would seem to be some virtue in buying a decent 3 or 4 stage charger and using that in place of the defective unit.

Against would be the hassle of an extra thing to have around and connect (and I don't like croc clips near LPG gas intstallations - they spark),

For would be a superior charging facility, both for the "leisure" battery and the engine starter battery, achieved at less cost.

sparxy said:
voltage stipulated by EEC regulations for 12-volt caravan equipment.
Click to expand...

BS EN 1648-1:2004 is the regulation if anybody wants to try and find a substantial extract on the net. Also specifies useful things like wiring sizes. 60 quid if you want to purchase a copy from BSI - which given that it's a statutory body, ought to be making the on-line versions free, but that's another rant entirely. ;)

Mild Red
 
Agreed a regulated supply is better. But most nominally 12v equipment seems to operate happily in a range 11.5 to 15V though. A bit of over voltage can usually be tolerated. Because after a long charge run on the alternator your battery may be giving 14v for a short while so 12v equipment has to be designed for this, as well as the lower voltages when the battery starts getting discharged.

That's why when my 240v charger is going giving 14.5v or whatever, the van equipment, fan, lights, inverter etc will still work quite happily. But for certain components such as tungsten lights or even LED's a higher voltage may lead to slightly lower life depending on their exact specification.
 
Horribly complicated, and getting a bit theoretical, but what about both a regulated power-supply AND a "proper" charger for use when shore power/Hook-up is available?

Advantages would be that as there is usually power to spare from the "mains", all the 12V items can be run at the proper voltage, AND you can charge the battery according to its requirements.

And whilst we're inventing the ideal - why not have an extra charger/circuit to charge the engine battery too.

I say extra because "smart" chargers get confused when they're trying to charge a pair of batteries together.

Not so complicated really - a switch to select the power source (regulated or "leisure" battery) using extra pairs of contacts to turn the battery charger on and direct its output to the battery when "regulated" is selected.

(Elf'n'Safety - don't try this unless you know what you're doing, all wiring, connectors and fitting is to the 12 V direct current extra low voltage electrical installation regulations, you know how to patch your fibreglass when the drill slips and you make a hole through to the outside world and you won't come crying when it's all gone orribly wrong. etc.)

Mild Red
 
thats why i dont like zig units etc ,you can make your own alot cheaper and have full control .but you have to get in to habit mode. i know some cant do the switching and changing as a habit.
 
greg butcher said:
can iuse a normal 12v - lead / acid / gel battery charger on 2amp to charge my leisure battery and need to loosen the cell caps
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Unless you are entrusting your expensive battery to some grotty back-street garage that hook it up to a 50-year old, 50 Amp unregulated boost charger that pumps in the amps until the electrolyte ends up all over the floor, you never need to take the caps off or even loosen them. In fact to do so makes it more likely for an external spark to cause an explosion. No battery manufacturer recommends this practice under normal charging conditions.

A 2 amp charger will likely be quite safe as long as it isn't a cheap taper charger and hooked to a small capacity battery. If it is some sort of "automatic" charger, it should drop back to float voltage well before the battery starts gassing
 
You could always go to Aldi tomorrow and buy a charger for £12.99.

If it is the same one as I bought earlier this year then it is a multi stage charger which has a 'maintenance' and 'pulse' function as well. It only charges at a max of about 3.8 amps but is good for maintaining batteries when the van is not in use.

BTW; a short burst of over 14 volts can be beneficial for a battery if done only now and again. It cleans the plates but you will need to check the electrolyte level and top up if necessary on non-sealed batteries.
 
Firefox said:
Agreed a regulated supply is better. But most nominally 12v equipment seems to operate happily in a range 11.5 to 15V though. A bit of over voltage can usually be tolerated. Because after a long charge run on the alternator your battery may be giving 14v for a short while so 12v equipment has to be designed for this, as well as the lower voltages when the battery starts getting discharged.

That's why when my 240v charger is going giving 14.5v or whatever, the van equipment, fan, lights, inverter etc will still work quite happily. But for certain components such as tungsten lights or even LED's a higher voltage may lead to slightly lower life depending on their exact specification.
Click to expand...

My fairly sophisticated solar panel regulator has a 14.5 phase which operates for about 1hour a month so as to agitate the battery sulphate and hopefully extend battery life.
However I'm fairly sure that even this short regime reduces the life of my incandescent bulbs. I'm changing to LEDs, and wondering how this will affect them. I can't tell when the boost charge is due and therefore cannot switch everything off in tme to avoid.
 
A lot of LED`s are rated up to 30 volts and have protection against spikes. As long as you do not get cheap ones you should be OK.

I have just ordered 4, 10 watt equivalents from Bedazzled at £6.50 each. They are coming down in price slowly. I previously got good ones from Aten lighting but their website was acting up last night and I could not complete the transaction. Both of these sites have a good range of bulbs.

It is still a lot of money to pay out if you need plenty of them but you need them when wilding.
 
The LEDs bulbs I've looked at don't have much of a spec. associated with them, so they could well be "cheaply" made at an expensive price. May well try the firm you've used.
 
BTW; a short burst of over 14 volts can be beneficial for a battery if done only now and again. It cleans the plates but you will need to check the electrolyte level and top up if necessary on non-sealed batteries.
Click to expand...

Standard charging cycle for flooded cell and many AGMs includes bulk charging at constant current until 14.2V to 14.4V is reached followed by an absorption cycle where the voltage is held at 14.4V while the current decreases. At a certain current and/or after a certain time, the charger switches to float mode.

As for lamp lifetime - any incandescent type (with a filament) will have a shorter lifetime if used when a three-stage charger is in the bulk or absorption cycles.
LED lamps incorporating a constant current regulator will be OK but where current limiting is done with a basic series resistor and the resistor is sized to give rated maximum current at say 13V, then at 14.4V the current could be 20 to 50% higher than rated and this could result in short life.
 
I believe some LED buls are supplied with a separate in series resistor. I suppose you could identify its colour code or measure its resistance value to see it's application suitability?
 
use gas lights much simpler and dont use any electric. ..light ,heat and keep mozzies away .cheers alan.
 
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