Split charge

[My Old Landy]

Over £100 is the cheapest branded one, but a split charge is cheapest option for now at under £40

I agree it is the cheapest way to go. I have the same in my 90. As I had no 35mm2 cable I bought the complete kit for around £60 with all cables and fuses. It works well

 

[Kayos]

The only vehicle I have seen that actually has a smart alternator is my 69 plate Caddy, volts swing from 11 to 15 depending on load, speed etc

15 plate L200, despite the internet saying I need a dc to dc charger it outputs a constant 14.4v, split charge works fine

17 plate Juke, modern diesel. Cigarette lighter volt meter shows constant 14.2v, im guessing the 0.2 volt drop is due to the wiring

Id never just connect the batteries together but unless you confirm it actually has a "smart" alternator a split charge relay will work, like they have for many years

 

[JMS1972]

240V is nice to cool fridge and charge leisure battery at home or on a campsite with power but not essential. Means I can have a small electric kettle too

 

[knighty]

It can charge both batteries but you have no sense of balancing the charge

for lead acid just charge them up to a smidge over 4v and they'll all balance/float/equalise themselves

you only have balance problems with lead acid if they never get a full charge, but on any type of car/van they'll get that all the time when you drive

 

[EBME2]

I don't understand what you mean? do you mean when charging from mains?


alternator can put out more than enough amps to charge two batteries, doesen't matter how many batteries you have in parallel, as they fill up voltage rises, as long as you take them up to float voltage (about 14v) they'll all be charged fully/evenly

O

 

[Cuthy246]

Picked up a second hand CTEK D250se for the van we are converting. Not cheap but does alternator charging and MPPT solar charging all in one unit. Can be used with lead acid, AGM and lithium batteries.

CTEK D250SE 20A DC/DC Battery Charger - 40-315

CTEK D250SE 20A DC/DC Battery Charger The CTEK D250SE is the successor to the D250SA and is designed to take power from smart alternators and other DC sources. The dual input allows it draw power from solar and wind sources as well. The D250SE can charge lead acid batteries up to 300Ah as well...

www.tayna.co.uk

 

[Gareth J]

Pardon our interruption...

I put one of these in a van. Buzzes a bit on startup and doesn't unlatch straight away. Get what you pay for I guess!

 

[carbon]

Picked up a second hand CTEK D250se for the van we are converting. Not cheap but does alternator charging and MPPT solar charging all in one unit. Can be used with lead acid, AGM and lithium batteries.

I have one for charging an agm battery that is powering my eberspacher heater and a few other things. The agm battery needs a higher voltage to charge than the alternator can provide

 

[Cuthy246]

I have one for charging an agm battery that is powering my eberspacher heater and a few other things. The agm battery needs a higher voltage to charge than the alternator can provide

Yeah, have an agm that came with it. Read the manual for the D250. Does all sorts of fancy stuff to keep the battery in good condition.

 

[julianf]

The ctek units are good, but the ocv on the solar side is stupidly low.

For any real use, it's better to get a 48v panel, another mppt, and just use the ctek for the battery to battery work.

 

[Bullet2012]

Shirley going Dutch is a real split charge

 

[Red'n'Black]

what year van is it?

don't bother with a split charge relay, just use a normal big relay and wire it's power to the small alternator wire (the one that does the light in the dash)

joins the batteries whenever the alternator is putting out power. works much better and it's more reliable

That's how I did mine.

It didn't work to begin with as the relay coil pulled too much current and the alternator wouldn't start up. Fixed that with a transistor to reduce the loading and it worked fine for the three years I had it.

 

[winchman]

Ended up buying this as once she has solar the solar will back feed to the starter battery, bloke was very helpful too.

All Split Charge

Split charging has been the tried and tested way to charge a lead acid deep cycle battery for a long time and is still suitable for most older vehicles

simplysplitcharge.co.uk

 

[Prajna]

I need to install one on the fridge feed so the battery only powers the fridge when the system is over 13v (i.e. charging or floating) because the fridge hammers the battery when it's cloudy or we forget to switch the fridge off after the sun has gone off the panels. I was going to design a circuit for it but my engineering abilities don't extend much into electronics and I had the idea that a split charge relay might do the job.

By the way, three way fridges (evaporation fridges rather than compressor fridges) only work well when they are perfectly level. Too far off and they turn into heaters rather than coolers, especially on gas! Don't ask how I know this.