MPPT to Battery cable size

[merl]

Go on.....show Kev your picture Trev

 

[colinm]

Go on.....show Kev your picture Trev

I expect Trev did try to load it, but you know how unreliable Linux is.

 

[trevskoda]

Could have done that Trev apart from 2 points

1. I’ve no idea what your talking about
2. My 4x4 doesn’t have hab batteries.

Thought it was your van, please pardon the fool i am.

 

[Boris7]

Thought it was your van, please pardon the fool i am.

You ain’t no fool Trev, natural mistake mate.

My 4x4 struggled to start after I left it for 6 weeks while away in the van on and off (needed to connect another battery and a power pack) and there’s no mains at the storage place. I’m off again soon and since I had a spare 125w panel and a victron MPPT in the garage thought I’d use them.

I also spend lots of time at race meetings and doing wildlife photography so use the EcoFlow a lot.

My thinking is a 120w panel and an MPPT will keep the battery in good condition and extend the EcoFlow’s life.

I’m also booked on a ferry to Spain soon and I’ve no idea how long I’ll be away and a new battery for the 4x4 is a costly option.

 

[trevskoda]

You ain’t no fool Trev, natural mistake mate.

My 4x4 struggled to start after I left it for 6 weeks while away in the van on and off (needed to connect another battery and a power pack) and there’s no mains at the storage place. I’m off again soon and since I had a spare 125w panel and a victron MPPT in the garage thought I’d use them.

I also spend lots of time at race meetings and doing wildlife photography so use the EcoFlow a lot.

My thinking is a 120w panel and an MPPT will keep the battery in good condition and extend the EcoFlow’s life.

I’m also booked on a ferry to Spain soon and I’ve no idea how long I’ll be away and a new battery for the 4x4 is a costly option.

A 40/50w panel will be more than required, simple to wire the regulator with a ciggy plug and plug it into the ciggy socket, leave the panel inside the w screen pointing at the sun mid day.
A cheap pwm at a few bucks will do what you want, no requirement for heavey cables at low wattage.

 

[Boris7]

But, I’d have to buy such a panel rather than use what I have, and the ciggy plug is dead when the ignitions off and the 4x4 can only be parked facing East behind a hedge or facing west when in the storage area.

 

[trevskoda]

But, I’d have to buy such a panel rather than use what I have, and the ciggy plug is dead when the ignitions off and the 4x4 can only be parked facing East behind a hedge or facing west when in the storage area.

Fut a second live ciggy plug and a cheap regulator to you panel, it will work well.

 

[Pudsey Bear]

Better too thick than too thin.

Just remember this does NOT apply to people too.

 

[barryd]

Its an interesting discussion this. I also didn't pick up this was for a vehicle battery. Our car gets left for months on end without use. In the past with the old Hyundai I just used to whip off the negative lead on the battery and that seemed to work ok. Not sure how the newer Suzuki Swift will react to that. A little panel somewhere might be a good idea.

 

[Wooie1958]

Approx 45cms from my Victron 75/10 to the 2 x 110AH Lead Carbon batteries and 4mm² cable worked perfectly

 

[merl]

A 40/50w panel will be more than required, simple to wire the regulator with a ciggy plug and plug it into the ciggy socket, leave the panel inside the w screen pointing at the sun mid day.
A cheap pwm at a few bucks will do what you want, no requirement for heavey cables at low wattage.

Yep, I agree. If you're not cycling and only maintaining then a cheap PWM and any old bell wire will do the job.
If you're relying on solar keeping a battery maintained during the winter though it may be a good idea to check the 'standing current' spec of the controller because this is actually a drain on the battery when there's no harvesting, If there's little/no sun and a SCC with high standing current you'll actually be worse off fitting a panel and controller! Victron controllers are very low standing current, just 10mA IIRC.

 

[trevskoda]

Its an interesting discussion this. I also didn't pick up this was for a vehicle battery. Our car gets left for months on end without use. In the past with the old Hyundai I just used to whip off the negative lead on the battery and that seemed to work ok. Not sure how the newer Suzuki Swift will react to that. A little panel somewhere might be a good idea.

Lead acid batteries go down in 2 weeks, once they drop to 12v they will never recover to a full charge, maybe 80% if lucky.

 

[barryd]

Lead acid batteries go down in 2 weeks, once they drop to 12v they will never recover to a full charge, maybe 80% if lucky.

Well I left it for a month just recently Trev and it was fine as was the Vstrom. In fact I left the Vstrom connected all summer once and it still started when I got back.

I checked with ChatGPT and it reckons ill be fine to just disconnect the Swift (car) battery. I have the radio code.

 

[colinm]

Its an interesting discussion this. I also didn't pick up this was for a vehicle battery. Our car gets left for months on end without use. In the past with the old Hyundai I just used to whip off the negative lead on the battery and that seemed to work ok. Not sure how the newer Suzuki Swift will react to that. A little panel somewhere might be a good idea.

Our Suzi's are happy to go months without being used as far as battery is concerned, however there can be other issues, they can get corrosion in the alternator which knackers it.

 

[barryd]

Our Suzi's are happy to go months without being used as far as battery is concerned, however there can be other issues, they can get corrosion in the alternator which knackers it.

Yes I had something similar happen to the Hyundai once. Not much I can do about it really. Shouldnt be an issue over Summer but ill maybe give it a squirt with WD40.

 

[trevskoda]

Well I left it for a month just recently Trev and it was fine as was the Vstrom. In fact I left the Vstrom connected all summer once and it still started when I got back.

I checked with ChatGPT and it reckons ill be fine to just disconnect the Swift (car) battery. I have the radio code.

We had a battery room when i worked in beards cars, my instructions came from a old chap who worked the room, he said min 2 weeks witout a charge on lead acids, dont know if this will be across the board with new tec gel or others, but many times i had to go to airport to jump cars that had been sitting 2 weeks, many of these were newish cars.

 

[barryd]

We had a battery room when i worked in beards cars, my instructions came from a old chap who worked the room, he said min 2 weeks witout a charge on lead acids, dont know if this will be across the board with new tec gel or others, but many times i had to go to airport to jump cars that had been sitting 2 weeks, many of these were newish cars.

How long ago was that advice Trev? Maybe modern cars and modern batteries are better but then again maybe there are more parasitic drains on them. That said old Hank the Tank from the last century was almost as bad as what you describe. I don't know if it was the crap immobiliser on the dash with a big glowing red or green light (not LED I guess) or something else but parking for more than a week or two I would disconnect the negative lead.

On the new van however the manual reckons it has some kind of cut off device so that if it senses its getting to too low a voltage to start the engine it somehow isolates it. Should never need to test that theory though as I have Merls Gizmott installed.

The Vstrom I guess is living proof that you can leave them for yonks but its a modern (ish) bike. The battery must be about ready to fail though as its the original from 2017.

 

[trevskoda]

How long ago was that advice Trev? Maybe modern cars and modern batteries are better but then again maybe there are more parasitic drains on them. That said old Hank the Tank from the last century was almost as bad as what you describe. I don't know if it was the crap immobiliser on the dash with a big glowing red or green light (not LED I guess) or something else but parking for more than a week or two I would disconnect the negative lead.

On the new van however the manual reckons it has some kind of cut off device so that if it senses its getting to too low a voltage to start the engine it somehow isolates it. Should never need to test that theory though as I have Merls Gizmott installed.

The Vstrom I guess is living proof that you can leave them for yonks but its a modern (ish) bike. The battery must be about ready to fail though as its the original from 2017.

True but its not good to keep a l acid sitting low, ok for lith to sit 3/4 charged, a small 5/10 smart charger hooked up inside the van as i have is handy, i just put the hookup lead in during nov/dec when little sun to charge both less and starter batts, my batts are now over 12 years old except starter one which died about 2 years back, but it was a second hand one with no history out of b inlaws boat.

 

[barryd]

True but its not good to keep a l acid sitting low, ok for lith to sit 3/4 charged, a small 5/10 smart charger hooked up inside the van as i have is handy, i just put the hookup lead in during nov/dec when little sun to charge both less and starter batts, my batts are now over 12 years old except starter one which died about 2 years back, but it was a second hand one with no history out of b inlaws boat.

I suppose in theory I could probably buy a small solar panel, stick it in the back window of the car on the drive, wire it through that old PWM controller and crocodile clip it to the battery in situ. In theory.

 

[trevskoda]

I suppose in theory I could probably buy a small solar panel, stick it in the back window of the car on the drive, wire it through that old PWM controller and crocodile clip it to the battery in situ. In theory.

Yep that will work, i used to have a small 20w panel with a cheap control unit glued to the back, lent it to a chap up the street as he was going away for a few mths, when he came back i ask for it back, yep a few big cracks in it where he turfed it in the boot under his holiday garbage.