Hank the Tanks Dodgy battery and solar system

[Pudsey Bear]

Its just a temporary thing for this trip. Ill have a little 12v socket right under my seat at the back where I sit above the battery. I just thought it might give me a better idea if the battery is in decline than relying on the three lights on the solar controller or the swift levels lights above the door. Generally in the old van I hit the button on the (wonderful) MPPT controller each evening before bed and it showed me where we were in voltage. The old system this time of year even with a crap day it would hardly ever drop below 12.5.

The problem is voltage is only half the issue you can have 14v from four AA batteries, but it won't do much to start the van, you need amps.

 

[barryd]

The problem is voltage is only half the issue you can have 14v from four AA batteries, but it won't do much to start the van, you need amps.

Ah but that is why you need to check it at the end of each night. Long after the sun has gone down (say 11pm) and you have had a full day and evening of draw on the battery. If you see say 12.5 each evening then you know its doing ok. If you start to see 12.5, 12.4, 12,3, 12,1 on consecutive evenings you know you are not going to sustain staying where you are off grid.

 

[Pudsey Bear]

Ah but that is why you need to check it at the end of each night. Long after the sun has gone down (say 11pm) and you have had a full day and evening of draw on the battery. If you see say 12.5 each evening then you know its doing ok. If you start to see 12.5, 12.4, 12,3, 12,1 on consecutive evenings you know you are not going to sustain staying where you are off grid.

Doesn't tell you the amps though, I had a ciggy socket meter once.

 

[barryd]

Doesn't tell you the amps though, I had a ciggy socket meter once.

Yes I know it doesnt show the amps but it will be a more accurate guide after a day under load to show the end of day voltage. We know the current battery starts off fully charged and charges up very quick but then it drops very quick under load as its (we think) knackered. This is just a way of me monitoring after a day and night of use if the "end of day" voltage is coping or not. Thats what I liked about my old controller. It never showed amps but it did show the voltage after a day of use so I was able to detect when it wasnt doing enough and we needed to go off looking for hookup.

 

[merl]

While the battery is relatively new and in good condition that device will give you an indication of how things are going relative to other nights for sure, problem is as the battery loses it's capacity it charges and discharges quicker (as you've witnessed) so the readings are no longer reliable or comparable.

 

[barryd]

While the battery is relatively new and in good condition that device will give you an indication of how things are going relative to other nights for sure, problem is as the battery loses it's capacity it charges and discharges quicker (as you've witnessed) so the readings are no longer reliable or comparable.

I appreciate that but it shouldnt start to deplete for a year or two surely. Enough for this trip at least.

 

[merl]

I appreciate that but it shouldnt start to deplete for a year or two surely. Enough for this trip at least.

The technical answer Barry is that the depletion starts on day 1 and continues very gradually from then on.
The rate of depletion of a lead acid battery will depend on many factors, depth of discharge and how much of its life it spends not fully charged being the main contributor. It's chemistry and type being the next.
The device will give you a better indication than your light system and the drop off in performance shouldn't be massive during this trip providing you don't repeatedly deep discharge it.
As kev has said measuring voltage doesn't tell you everything, that's especially true as the battery gets knackered.

 

[Nabsim]

I appreciate that but it shouldnt start to deplete for a year or two surely. Enough for this trip at least.

I killed 3 Bosch PowerFrame battery’s in 12 months Barry which is why I have been on lithium five years. If you are taking lead too low they die easy and quick.

That said one of them served as a good starter battery for another 12 months or so but was useless for habitation

 

[barryd]

Maybe thats why the AGM battery we had last couple of years was so much better then. However the previous 120 Alphaline (I think) bought in France in 2015 coped well under the same regime for several years. It was never as good as the AGM 120 though. In theory in August with a 120 panel and a 120 battery you would think with our usage it would never drop much below 12.5 which is what happened before but a lot of unknowns here. Anyway its either going to work or it isnt. After this trip its back to the drawing board and you will have the rest of autumn and all winter to come up with a nuclear solution!! Note the use of the word "you".

 

[Nabsim]

Mine was abusing the battery’s Barry, others have had them in for years, they just weren’t suitable for how I use power. Probably if I fitted twice as much they would have coped but then it put cost almost the same as lithium to me event back then

 

[barryd]

Mine was abusing the battery’s Barry, others have had them in for years, they just weren’t suitable for how I use power. Probably if I fitted twice as much they would have coped but then it put cost almost the same as lithium to me event back then

I want it properly fettling eventually. Sockets where I need them, Lithium and more solar. I want over the top for our needs really. Hopefully without spending an outrageous amount of money. Budget £1500-£2000.

 

[Nabsim]

Budget can be a shock even fitting yourself Barry lol

Pity David isn’t taking on more jobs, unless he is again of course

 

[mariesnowgoose]

Budget can be a shock even fitting yourself Barry lol

Pity David isn’t taking on more jobs, unless he is again of course

Selective only I think, Neil.

He's semi-retired and, like most of the rest of us - if we're sensible! - does only the jobs he wants to, or finds interesting and challenging.

Which is exactly the way it should be!

 

[mariesnowgoose]

You guys should have yourselves a "power meet" - or a big "pow wow"

Talk round the fire about the pros and cons of batteries, solar and all your fancy gadgets to your hearts content for hours on end (or 'til the cows come home ).

Me, I just want something simple and neat I can "plug in and go" and not worry about some bespoke rats' nest of cables and controllers that will confuse the hell out of me if something goes wrong...

 

[mark61]

Selective only I think, Neil.

He's semi-retired and, like most of the rest of us - if we're sensible! - does only the jobs he wants to, or finds interesting and challenging.

Which is exactly the way it should be!

Or in other words, like many semi retired, sensible enough to only work for people they want to work for.

I'm always being asked by neighbours etc, if I know, a gas fitter, electrician etc I can recommend. Yeah, I know plenty I'd recommend, but not so sure I'd recommend the punters.

 

[barryd]

Budget can be a shock even fitting yourself Barry lol

Pity David isn’t taking on more jobs, unless he is again of course

I've already asked him, said no. (so far) Might need to bring out my persuasive skills and if that dont work, has anyone got any dirt on him?

 

[mariesnowgoose]

I've already asked him, said no. (so far) Might need to bring out my persuasive skills and if that dont work, has anyone got any dirt on him?

What you want doing is a biggish job and requires mucking about with the wiring on a factory-built motorhome. Yuk!

It can be a messy, very time consuming job, and if I were in David's shoes I would say no too!

Even just fitting a new leisure battery in our old autosleeper, which should have been a quick, straightforward "slot out/slot in" job turned out to be more complicated that you would ever think.

 

[TeamRienza]

I use on of these Ring multi sockets.

12V In-Car Power

www.ringautomotive.com

Mounted on a wall beside a 12 volt outlet, it has one of the little digital voltage display plugins in one outlet, a TV power supply in another, leaving one (my model has 3 outlets) for phone charging etc.

The little digital plug is useful for showing resting voltage, as the master switchboard varies with solar input by day. At night using the TV for showing dvds, the voltage will show as 11.2 volts, while the master display is showing 12.5 or 12.7 volts, so of limited use.

Davy

 

[barryd]

What you want doing is a biggish job and requires mucking about with the wiring on a factory-built motorhome. Yuk!

It can be a messy, very time consuming job, and if I were in David's shoes I would say no too!

Even just fitting a new leisure battery in our old autosleeper, which should have been a quick, straightforward "slot out/slot in" job turned out to be more complicated that you would ever think.

I'll have some breathing space to get my head round it all now anyway at least rather than blundering ahead while away. It's more tech than nuts and bolts so I should be all over it really with my background and I will be eventually. I just can't do any of the physical work myself. Understanding exactly whats required though will help me find someone who can. There must be a solar lithium guru up north surely.

 

[trevskoda]

Get yourself some good lead acid replacements. They have worked well for generations and for full time use. Would never have lithium crap in my van. Lead acid is tried tested and works very well and always has.

Nothing like old hat.