Controversial! Why Solar can damage your batteries! (1 Viewer)

[funflair]

specific gravity = 1.265 - 1.280 At 26C

That's OK with open lead acid, but how many have these.

 

[funflair]

I thought most leisure batteries were either AGM or Gel batteries. How would these be affected I wonder. Also, 250 cycles does not sound a lot? Mine are quoted at 1000 and there only mid range AGM batteries. (Now discontinued).

Lots are sealed lead acid, some good lead acid are open so you can check levels and maintain AGM are essentially lead acid and GEL are the least common and most expensive IMO.

 

[Mike B]

That's OK with open lead acid, but how many have these.

Me, Me, Me

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[funflair]

Me, Me, Me

OK that's 3 then.

 

[vwalan]

me . best bet i say . cheap ,cheerfully do the job .

 

[scotjimland]

wouldn't buy anything else.. el cheapo flooded lead acids..FLAs
in saying cheap.. I generally buy a reputable brand..

when I lived in Essex I always went to the the battery factory in Leigh-on-Sea for mine, straight off the production line.. .. Lincoln Batteries

Cracking good batteries , no middle man.. no factory shop.. you deal with the guy in the store room.. I think you can order on line

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[jonandshell]

I thought most leisure batteries were either AGM or Gel batteries. How would these be affected I wonder. Also, 250 cycles does not sound a lot? Mine are quoted at 1000 and there only mid range AGM batteries. (Now discontinued).

That is 250 cycles per year over a five year warranty period!
Well cared for traction batteries can last much, much longer.
I have one customer with a 13 year old battery on a reach truck, the specific gravities are all still fine.

 

[Peter_n_Margaret]

A few views of mine .......

Wet cell lead acids, sealed wet lead acids, AGMs and GELs are all lead acid batteries.
Sulphating can affect all lead acid batteries, but it is unusual for AGMs and GELs to be affected.

The usual solution is to over charge in a controlled manner. This is often called "conditioning" or "equalisation" charging. This can cause gassing. The gas produced is hydrogen which in some specific concentrations with oxygen (air) can be explosive.
All lead acid batteries should be housed in a vented compartment to ensure hydrogen concentrations can not reach a dangerous level if gassing occurs.
All lead acid batteries (including sealed wet cell, AGMs and GELs) will gas if overcharged either deliberately or accidentally.

AGMs and GELs are also described as "VRLA" batteries which means Valve Regulated Lead Acid batteries. Generally, minor gassing is reabsorbed into the matrix without being released. If they are overcharged and gas excessively, the valve in the case will open to relieve the internal pressure (so the case does not burst). If this happens, hydrogen will be released.

Solar panels won't damage your batteries, but undercharging them on a regular basis (by any means) may.
Many good quality solar regulators can perform conditioning/equalising charging if that is recommended for particular batteries.

The number of cycles that batteries can operate for is generally determined by how well they are charged after use and the depth of the discharges. The type and quality of manufacture also has significant effect.
I use Fullriver 'DC series' AGM batteries. A cycles Vs depth of discharge chart for these batteries is attached.

 

[laneside]

Only just picked up on this thread and it somewhat reminds me of the one that says smoking will kill but flipping heck how long does it take. We have a four year old battery off our previous caravan and a three year old one we got with the new van and they are charged with sometimes mains hookup and sometimes by solar. If they drop dead tomorrow it has hardly been a great expense for the use that we have out of them. Similar with smoking kills we have both smoked for fifty odd years now so how long does it take ?

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[jonandshell]

We all agree that undercharging sulphates batteries.

Now, can you be sure your batteries are fully recharged before the sun goes down?
You can be sure with the on board 240v charger or a B2B!

That is the point of this thread.

 

[vwalan]

but only if on ehu or running the motor . both can be not nice if miles away from anywhere in a nice peaceful beauty spot .
mind in winter in spain or morroco. they usually are full up before lunch on sunny day .

 

[Al-Di]

Interesting,

Thank you,

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[tonyidle]

The scenario you had Alan, was that the batteries were partially discharged then recharged fully.
It is not the shallow depth of discharge that causes lead acid battery sulphation but the failure to completely recharge.
You are right in saying that you can discharge a lead acid battery any amount (but not beyond 100%) and no 'memory effect' or sulphation takes place.
Its the full recharge that is critical.

This all makes perfect sense but in most cases imperfect charging whilst on site isn't too long term? Once the van is back home & hooked-up the (modern) van charger will operate its boost cycle and give the batteries the full charge they need. Even on the road the alternator, whilst not running long enough to fully charge the leisure battery, will at least charge at a reasonably high current. The A2B or B2B systems will do the same even more effectively.

 

[tonyidle]

The gas produced is hydrogen which in some specific concentrations with oxygen (air) can be explosive.

It's worse than that: two gases are produced (hydrogen and oxygen) in perfect proportions to explode and produce ................ water. There have been a number of industrial accidents over the years caused by sparks from connecting / disconnecting batteries.

Broken Link Removed

 

[jonandshell]

They ain't pretty when they go!

Last year a forklift driver at one of my sites changed a battery, all 48 volts, 600Ah and 850kg of it, and whilst doing so trapped the power take off leads causing an explosion and the truck to catch fire!
Fortunately, he only caught a few plastic fragments and was OK.

Never underestimate the volatility of battery gasses in concentration!

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[wizzer59]

specific gravity = 1.265 - 1.280 At 26C

Thanks Mike

Thing is if you guys think I'm gonna undo four bolts and lift my very heavy seat out of the way just to test my battery every time I need to find out if its fully charged or not, you got another thing coming, life is definitely to short and as long as the lights come on thats good enough for me all I know is come what may, when I go out to my motorhome, even if it has been sat there for a month or two, my batterys are charged up ready to go without me lifting a finger. (Please note I didn't say "fully")

 

[haganap]

I do feel sorry for new mh owners reading these type of threads....bless them if they were not confused before they are now...

 

[voyagerstan]

if it works don't fix it \STAN

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[Tootles]

We have a Rutland wind charger on our narrowboat. It trickle charges the batteries, (a bank of six lead acid truck batteries). The oldest battery in the bank I bought new in 2004. The charger keeps them 'warm' in winter, and apart from the whooooooosh noise, its great.

 

[wizzer59]

I do feel sorry for new mh owners reading these type of threads....bless them if they were not confused before they are now...

They ain't the only one's Paul

 

[dabhand]

Very interesting this thread and I am slowly trying to assimilate the info contained within it. When at home I keep the moho on 240v permanently, is this wrong/dangerous. The van has solar but it's kept in my barn. Is there a foolproof way of testing the condition of the batteries (Leisure and vehicle) and also of knowing if the batteries are fully charged.

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[Bertie Bassett]

......... sometimes I'm glad I'm thick.. I don't understand any of this ..... it would only give me something else to worry about if I did..

Once again here on Fun I find I am not alone! Thanks!

 

[Lisa]

Great thread Jon and I have a little question......can you over charge a battery? Say you left it on charge for 3 days as opposed to 16hrs

 

[JockandRita]

That's OK with open lead acid, but how many have these.

Me, Me, Me

Me too.

Cheers,

Jock.

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[haganap]

Very interesting this thread and I am slowly trying to assimilate the info contained within it. When at home I keep the moho on 240v permanently, is this wrong/dangerous. The van has solar but it's kept in my barn. Is there a foolproof way of testing the condition of the batteries (Leisure and vehicle) and also of knowing if the batteries are fully charged.

No it's not dangerous. I've done it for 10 years.

Get a nice NASA battery monitor and you will know

 

[movan]

Great thread Jon and I have a little question......can you over charge a battery? Say you left it on charge for 3 days as opposed to 16hrs

bump

 

[jonandshell]

Great thread Jon and I have a little question......can you over charge a battery? Say you left it on charge for 3 days as opposed to 16hrs

It is only bad for your battery if you have a fixed output charger. Many vans now have smart onboard chargers and they can be left on, maintaining the batteries with a 'float' voltage.

Your older Sargent PSU has a fixed output charger contained within as far as I know and shouldn't be left on indefinitely. A good way to check this is to leave it on for a day then check the battery voltage with a multimeter.
If it has a 'float' function, it should read about 13.4 volts. Continual charging at a higher voltage will cause damage over time.

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[movan]

 

[scotjimland]

 

[jonandshell]

Very interesting this thread and I am slowly trying to assimilate the info contained within it. When at home I keep the moho on 240v permanently, is this wrong/dangerous. The van has solar but it's kept in my barn. Is there a foolproof way of testing the condition of the batteries (Leisure and vehicle) and also of knowing if the batteries are fully charged.

Hi there are two methods.

1. Use a battery hydrometer to !measure the specific gravity of the cell electrolyte. A reading of 1.265 to 1.275 is fully charged.

2. Measure the open circuit voltage of the batteries. With everything switched off, measure the battery voltage with a multimeter. 12.7 volts is fully charged.

It is important to note that after charging, a 'surface' voltage can be present giving a false high voltage reading. Switching on a light for a couple of minutes reduces the battery voltage to its real state and allows accurate measurement.

Lots of people claim their batteries read 13 volts plus when charged up. This is just that 'surface' voltage and it does not reflect the battery's true state of charge.
This also perpetuates the myth that their batteries have fully charged after only a few minutes of engine running or solar use!!!

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