Using a Smart Charger to Maintain Vehicle Battery

[Hondaman]

Hi All,
Although my MH is kept at home and I have an electric hook-up post, I would like to use a Smart Charger to maintain the vehicle battery.

Having used Smart Chargers on my motorcycle collection for many years, I really appreciate how long lead acid batteries last if kept properly maintained.

The MH is a 2020 Dethleffs fitted with a Schaudt EBL 119A charger/transformer.
As you probably know, this only gives a float charge to the vehicles battery whilst connected to the 240V supply, and is not enough to fully charge the battery if it is partially discharged.

Ideally I plan to fit a flying lead from the smart charger, either directly to the battery, or for ease, to the jump start terminals under the bonnet.

My concern is this:
If the Smart Charger is pumping, say 14.7V into the vehicle battery during the bulk charge cycle, is it likely to damage to Schaudt EBL 119A charger/transformer?
Should the 240V hook up be disconnected, in order that the on-board charger/transformer isn't also trying to charge the vehicle battery?

Has anyone used a Smart Charger for vehicle battery maintenance, and if so how do you connect it?

All advice gratefully received.

 

[autorouter]

My concern is this:
If the Smart Charger is pumping, say 14.7V into the vehicle battery during the bulk charge cycle, is it likely to damage to Schaudt EBL 119A charger/transformer?
Should the 240V hook up be disconnected, in order that the on-board charger/transformer isn't also trying to charge the vehicle battery?

Has anyone used a Smart Charger for vehicle battery maintenance, and if so how do you connect it?

It's quite common to connect two chargers at the same time in motorhomes. For example, mains charger and solar charger, or alternator and solar charger. The chargers have a diode (electrical one-way valve) in the output circuit, to stop any back-feeding. The charger that's putting out the highest voltage gets to do the charging. No need to disconnect the hookup, it will be charging the leisure batteries too.

Usually float charging the vehicle battery isn't a problem for motorhomes. It arrives on a site with hookup, or back at home, after a drive that's long enough to fully charge it, so it's just a matter of keeping it fully charged. And those that don't do sites with hookup usually have solar panels, with some arrangement like a dual controller or battery maintainer to keep the vehicle battery charged too.

To connect a smart charger, I'd get one of those that has a 2-pin connector in the output lead, and wire the other section directly to the battery. So you can use the charger on different vehicles - I'm sure you do that already on your bike collection.

There's a couple of ways to connect to the starter battery via the EBL. At the back of the EBL there are big terminal connectors for the leisure battery, starter battery and common negative. Be careful of the colours, they might not be what you expect. On mine black is leisure battery positive, for example.

Alternatively the 5-way connector has wires to the starter battery - Pin1 positive, Pin4 negative. It's the wire that supplies the fridge 12V element when the engine is running.

 

[Hondaman]

It's quite common to connect two chargers at the same time in motorhomes. For example, mains charger and solar charger, or alternator and solar charger. The chargers have a diode (electrical one-way valve) in the output circuit, to stop any back-feeding. The charger that's putting out the highest voltage gets to do the charging. No need to disconnect the hookup, it will be charging the leisure batteries too.

Usually float charging the vehicle battery isn't a problem for motorhomes. It arrives on a site with hookup, or back at home, after a drive that's long enough to fully charge it, so it's just a matter of keeping it fully charged. And those that don't do sites with hookup usually have solar panels, with some arrangement like a dual controller or battery maintainer to keep the vehicle battery charged too.

To connect a smart charger, I'd get one of those that has a 2-pin connector in the output lead, and wire the other section directly to the battery. So you can use the charger on different vehicles - I'm sure you do that already on your bike collection.

There's a couple of ways to connect to the starter battery via the EBL. At the back of the EBL there are big terminal connectors for the leisure battery, starter battery and common negative. Be careful of the colours, they might not be what you expect. On mine black is leisure battery positive, for example.

Alternatively the 5-way connector has wires to the starter battery - Pin1 positive, Pin4 negative. It's the wire that supplies the fridge 12V element when the engine is running.

Thanks for the detailed reply.

You are correct, all of my motorbikes have a permanently fitted 2 pin fly-lead directly from the battery terminals.
It's then very easy to just plug them into the intelligent chargers that I have.
I will probably go the same way with the MH's vehicle battery.

What I like about the intelligent chargers is that they continually monitor the state of the battery and then if required they will start the whole charging regime again, beginning with the bulk charge of circa 14.7V if necessary.

 

[autorouter]

I take a couple of 125cc bikes with us, and also a CTEK MXS5.0 smart charger. It has a bike mode and car mode, so is fine for charging the bikes and the MH battery if necessary. A few times it's come in handy for other motorhomers when their charger isn't working. It once earned me a bottle of very nice wine on the St Emillion site.. And I have another of those chargers that I leave in the car on the drive when we are away, so it starts first time when we get back.

 

[Hondaman]

The CTEK MXS5.0 is one of the smart chargers that I already have, (plus 4 more Optimates!). That's a good idea, taking it with you to keep the motorbike charged up to .

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