Split relay charger..

[MJK]

I have one of these to charge my second battery, but after a 4.30 hour drive to Cornwall it fried the second battery..
Think it over charged..
Would it be because it was charging constantly for to long or because the battery was not good.. It is / Was an oldish leisure battery and only small.. 75ah..
Thanks..

 

[Bigshug]

I think that would overcharge your leisure battery on a long journey!! What a split charge relay does is connect the charge from the alternator to your leisure battery, it does not control the level of charge, a B2B charge controller is needed to prevent the battery from being overcharged

 

[mistericeman]

I think that would overcharge your leisure battery on a long journey!! What a split charge relay does is connect the charge from the alternator to your leisure battery, it does not control the level of charge, a B2B charge controller is needed to prevent the battery from being overcharged

The alternator 'should' throttle back the charging once starter and leisure are charged ...

All the VSR Does is connect both together at the appropriate voltage .

Chances are the LB was on its last legs ...

Though a battery to battery charger is a better option charging and battery health wise .

 

[Pudsey Bear]

I used the Ring smartcom VSR on my selfbuild it was adjustable for when it cut in and out.


Couldn't find one for sale now, but they were very popular and reliable.

Fridge 12v relay ?

I'm fitting a Dometic RM123 three way fridge, the 240v connection is straight forward as is the gas - the 12v had me stumped as it (as I understand) requires a relay (?) from the battery to the fridge, are all relays the same or do I require a certain type ? 😮

motorhomebuilder.com

 

[CriftinsCampers]

Ironically I had a van in this week for a charging fault, owner had been up in Scotland for 5 weeks and her Xantrex inverter running her fridge haad been giving regular low voltage alarms!

Imagine my surprise to find the 150A fuse from the chassis battery to the VSR missing.
I found it soon after cable tied out of the way.
It turned out she had paid a cough 'auto electrician' to fit new batteries in her van.

The cowboy fitted a mismatched pair of so called leisure batteries (i.e those unbranded dirt cheap poor quality starter batteries with a leisure sticker on them often sold on ebay) wired in parallel... He didn't even get her a matching pair one is 110Ah the other 75Ah and he completely forgot to refit the fuse....

She had managed to do almost her entire trip totally reliant on solar and whatever capacity the mismatched combo delivered overnight

However although I am not a great fan of split charge, too inefficient for my liking especially with a 14v alternator, the one in her van has a really useful feature of bi-directional charging, as soon as Solar went above the VSR 13.7v threshold it switches on and charged the chassis battery... well it does now anyway!

So her PPT 140A Dual sense VSR seems a really easy and cheap way to obtain bi-directional charging

 

[merl]

View attachment 73685 I have one of these to charge my second battery, but after a 4.30 hour drive to Cornwall it fried the second battery..
Think it over charged..
Would it be because it was charging constantly for to long or because the battery was not good.. It is / Was an oldish leisure battery and only small.. 75ah..
Thanks..

View attachment 73685

The split charge relay simply connects the alternator to the leisure battery, the starter battery is permanently connected to the alternator so you could view the SCR as connecting the 2 batteries in parallel.
Soo why would the alternator keep one battery topped up and destroy the.other?
The answer is the leisure battery was old and deposits within the battery itself caused one of the cells to short circuit. The battery is now a 5 cell battery and not 6 and consequently the new 5 cell battery is receiving 20% excessive charge voltage and massively overcharged. So yes the battery was already knackered.

 

[MJK]

Bless...
Thanks for all your feedback...
Much appreciated and I will be going to get a new battery on pay day, plus put something in place to prevent over charging...
In my little tin tent I have put in a voltage display and a 80 amp trip fuse where I can see them while driving and I just turn power onto relay via trip fuse if voltage is low on leisure battery..
I just used what I had in my shed lol..
Thanks ever so again...

 

[trevskoda]

Bless...
Thanks for all your feedback...
Much appreciated and I will be going to get a new battery on pay day, plus put something in place to prevent over charging...
In my little tin tent I have put in a voltage display and a 80 amp trip fuse where I can see them while driving and I just turn power onto relay via trip fuse if voltage is low on leisure battery..
I just used what I had in my shed lol..
Thanks ever so again...

Buy a loach lead carbon battery and not a so called les battery which are glorified starter batteries, some may have thicker plates inside but old hat these days.
Some of these so called auto regulator/switch only bump in 13.7 ish volts, make sure you are getting the full monty 14.4 at least, mine is a manuel 200ah relay and switch, just have to remember to use it once started and turn of when stopped, cost about 8 bucks all in, battery under £200.