3 way split charger system

[CovKid]

http://www.keithandsylvia.co.uk/main%20 ... e_page.htm

[pfield69]

Hi,
I have seen the basic diagram in the wiki for a split charge system but as I like to do thinks the hard way I thought I'd best ask the experts.

I have had to change my alternator so have now got a 90A unit. I'm going to buy a leisure battery (the biggest that will fit under passenger's chair - any idea of sources?). As I'm a cheap scape but must have a fridge for medical purposes, I was going to fit a large solar panel over the rear offside window (which will eventually be behind a unit). This panel will produce 35 or45W (depending on the one I can get). The fridge will draw 35w peak.
I'm thinking that the panel should be disconnected before the van is started and the leisure battery not charged until the van IS started.

Does anyone have any ideas how to do this?

Also where is an easy place to break into the alternator light cable?

[AngeloEvs]

First, based on the wattage of the fridge I am assuming that you have a compressor model and not the the 3 or 2 way absorption type usually fitted as standard in most vans (which would draw around 95 watts).

Second, your Solar Panel will need a regulator to prevent overcharging the leisure battery unless you disconnect it when the van is not used for camping.

With a normal split charge system your leisure battery will be disconnected from the alternator untill you start the engine as this is the function of the relay used in conventional split charge systems. You can therefore leave the solar panel connected 24/7 to the leisure battery (via the solar panel regulator) and leave it connected while you are driving.

Most solar panels include a blocking diode in their construction but not all. The function of this diode is to prevent the leisure battery bleeding current into the panel at night and 'flattening' the leisure battery. Some regulators have this diode but some don't. Basic Solar panel Regulotors are cheap but the intelligent switch mode type are expensive and really designed for 80-W panels and upwards. Both are simple to connect into a solar panel set up - you connect the panel to the regulator and the regulator to the leisure battery terminals.

Yoy then fit the split charge system in the normal way - both your leisure battery and your solar panel will be isolated from the starter battery untill the engine is up and running.

[CovKid]

Theres a first - my answer appeared above the question - spooky

[pionte]

If you use an intelligent relay then you wont have to break into the alternator light circuit

I have just installed a split charge system and Leisure Battery. I will find the link to the battery that I bought and fitted, it was just the right size, 85 AH and about £65 delivered IIRC !

Theres a first - my answer appeared above the question - spooky

You are indeed a wise old one..... being able to answer BEFORE the question is even asked !!

Erm dont suppose you know the lotto results for tonight do you??

[CovKid]

I'm sure it was a site glitch as I posted it in early hours. Spooky though. The lottery results for tonight will be......hang on, doorbell.

[bigherb]

Also bear in mind a 40w solar panel is it's maximum output in bright sunshine. In practise the actual output will be lower for most off the time.

[pfield69]

Wow! how did you know I was going to ask this?

Angeloev: You right, I have the table top compressor type of fridge. Its a bit of a gamble with all the fuss that they make about settling but a frindly refridgeration engineer thinks it will be ok. The advantage is that it won't run all the time and cost me £20 instead of £400ish for a 3 way.

I haven't actually got my hands on the panel yet but it would have been £500 new the output is 17v DC but I don't know what technology is inbetween output and glass. I will have to use a voltage regulator (or even a dc-dc transformer) to get the right voltage.

Thanks for the help

[Oldiebut goodie]

Surely you are not going to get much charge from a panel in that position? Panel needs to be horizontal rather than vertical. Or have I misread your intention?
As above:-
No need to disconnect at any point.
Ensure that you connect the regulator to the battery before you connect the panel to the regulator.(use a proper solar panel regulator)
Connect a split charge system as normal.

[AngeloEvs]

Solar panels produce anywhere between 19V and 23V depending on light level and this is normal for a 12v charge system. The regulator simply controls how much charge current is going into the leisure battery depending on its needs. You do not need a DC to DV convertor unless the Compressor fridge runs at a higher voltage which leads to my next question.

Is the compressor fridge a domestic one that runs of 240V AC? In which case you have a huge problem as 35W at 240V translates to twenty times higher at 12V and your leisure battery (even with a 40W solar pane will not be able to provide the energy needed. Compressor fridges designed for leisure vehicles have low energy compressors and are usually able to run of both 12V and 24V DC. These are expensive with prices starting at around £240 for the Waeco but have very low current consumption and are simply connected to the leisure battery with nothing else required (A solar pane;l is useful if you intend wild camping for days on end and not using the van to replenish the charge.

Rather than spend hundreds of pounds on a Solar panel I would invest in the entry level Waeco CF compressor fridge and not bother with a solar panel unless funds permitted. I have used my 12V Waeco CF for five or more days without 'hook -up' running purely of the leisure battery. They include energy management settings to prevent the lesiure battery becoming 'flat'.

[KarlT]

Looks like there are some people who know what they are talking about.
I'm wanting to fit a split/leisure battery set-up in my van but have been warned that some ECU's don't like some Split-charge set-ups & may give fault readings.
I'm fitting a Subaru EJ25 conversion.
Any ideas? True or not?

[kevtherev]

Tosh... Karl