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[ianb]

Quick question for all you experts on batteries out there.

"Expert" is anyone who knows more than I do. so it means everybody else.

I want to use 2 lead acid (sealed) 12V batteries in my Aziz, one for each motor. I was advised on this forum not to wire them in parallel, so I won't!

If I lay them on their side instead of upright am I going to have problems, either in use or when charging?

Thanks in advance.

Ian

[Shipmate60]

In a word no.
SLA (Sealed Lead Acid ) batteries are designed to be used upright or on their side.
I would however recommend that you remove the batteries from the model for charging.
They can exhaust Hydrogen, which is an inflamable gas.
They shouldn't, but CAN.

Bob

[ianb]

Thank you Bob.

Your reply has put my mind at ease.

Cheers

Ian

[IainM]

Agree with Bob.
Only thing is that SLA's must be charged in the upright position i.e. terminals on top to ensure safe absorbsion of any gases within the cells.

IainM

[Colin Bishop]

Only thing is that SLA's must be charged in the upright position i.e. terminals on top to ensure safe absorbsion of any gases within the cells.

Never done that myself. Mine are built in lying flat and that's the way they get charged. Never seen any instructions to the contrary and never had any trouble either! I don't charge at high rates though - overnight is fine.

[wingertaz]

Hi,
   You would think that a sealed battery could be used and charged any way up But they are designed to stand upright to get the best out of them. I have a number of these in use some are laid flat and some upright. The performance is the same in use no matter what there position. I do however always remove them from the models for charging and stand them upright for an hour or so before charging them at an ideal rate of 10% of there capacity.
    I wouldn't recommend charging any type of battery in the model after seeing what can happen when things go wrong. :(

Regards Gary

[Peter Fitness]

I also use my SLAs in any position, but always remove them for charging. The subject of charging in an upright position, or whilst on their side seems to provoke much debate. One of our members is an electrician and electronics guru, and he says that it makes absolutely no difference. However, because I remove mine, they are charged while upright as it is easier to do so, and they take up less bench space.
Ian, why were you advised not to wire them in parallel? Wiring two batteries of the same voltage in parallel maintains the same voltage but doubles the capacity, whereas wiring them in series double the voltage but retains the capacity.
For example, 2 x 12v, 6ah batteries in parallel = 12v and 12ah. The same two batteries in series would give 24v but still only 6ah.
Peter.

[gingyer]

Hi All
At the moment I am working on major automation work all the equipment is battery powered with a trickle charger.
The batteries are all 12v but some of the kit is 24v so they connected in series or others are 12v with a heavy load so
they have been connected in parallel. All this has been done by the manufacturers at factory level with the battery manufacturers
approval so there seems that there is no problem using the batteries in series as suggested.
On the subject of positioning the kit is supplied most of the batteries are upright but some kit comes with the batterries on their side
so there is no reason that the batteries need to be a set way for charging only requirement is that they are ventilated due to hydrogen
that the can give off.

All the Kit I should point out has been extensively tested by ALL those who have manufactured any part on it prior to it being issued.
and if they they have no issues with it I don't think we can have any problems

just my thoughts
Colin

[Ghost in the shell]

well in Celestia I have one BIG A$$  sealed gel battery that is a swine to remove and replace, as ALL the electrical wires have to come out to give room for the battery to removed.  it is a 6v 12ah and it lies on its side.  manual states "can be charged in any position except upside down", lying on its side has not been an issue at all, doesnt as much as burp

[Ghost in the shell]

bob, on the hydrogen issue, I remove the hatch directly above the battery,

[Ghost in the shell]

...I was advised on this forum not to wire them in parallel, so I won't!...

parrallel wiring batteries isnt an issue, though I dont parrallel wires in Celestia or Yamato, I wire nickel types in parrallel in my speedboat. mainly I have not wired the lead gel types in parrallel, I dont need to!

[Shipmate60]

Ghost,
Charging in the model isn't an issue with everything being fine.
If you get a slightly high internal resistance this will produce heat which will increase the internal pressure within the casing.
The Safety Valve is there to allow excess pressure to escape, this is the Hydrogen!!
I would always advise charging out of the model for safety, but this is your choice and risk.
Most rechargeable batteries on my ship are of the SLA type and are still recommended to be charged in the battery Charging Compartment with forced ventilation.

Bob

[ianb]

Lots of advice and information for my poor old brain to try and absorb! Thank you all very much for your replies.

Peter Fitness and Ghost in the shell:
   In the last topic posted by me (12V to 6-7.2V), it was suggested by HS93 that wiring SLA batteries in parallel was perhaps not a great idea.

                                     http://www.modelboatmayhem.co.uk/forum/index.php?topic=7830.0

I took this as being a strong suggestion that maybe I ought to consider an alternative. Perhaps I misread HS93's advice. If I wire the two batteries in parallel, then the wiring does become simpler for me.

I'm still a bit confused, but this forum is certainly helping me to become less confused and not make a big mistake.

Thanks again,

Ian

[wombat]

Yuasa say this in their NP battery series datasheet:

Operation in any Orientation

The combination of sealed construction and Yuasa’s
unique electrolyte suspension system allows operation in
any orientation, with no loss of performance or fear of
electrolyte leakage. (Excluding continuous use inverted)

The recommendation from other manufacturers is operation and charging upright or on the side. On the balance of evidence, IMHO, never operate the battery inverted and certainly never charge with it inverted.

I charge with the battery in the boat, but with the cover off - I have my boats equipped with 1/4" jacks so the charger plugs straight in - it also prevents you closing the cover inadvertantly or in an absent minded moment because of the sheer size of the plug

As for paralleling batteries - well it should be OK, but if it were me, I would use diodes on the output of the batteries - 1 diode per battery with the anodes connected to the positive terminal. Join up all the cathodes and take that to the rest of the circuit. This will prevent any problems associated with a cell failure in one of the batteries.

Wom

[malcolmfrary]

Combining batteries is not a problem provided the batteries are compatible in the way they are being used and as long as they are in matching condition.  We have to remember that some members have spent their working lives dealing with batteries and have the "rules" firmly in the back of their minds, some have not, and anything electrical is a mystery to them. 
Being familiar with rules gives you the ability to bend them without breaking them, but where there is a serious safety issue, you cant take chances with somebody else.  The result is that we tend to give advice that errs on the safe side for a beginner to this particular aspect of the hobby.
When a vehicle manufacturer combines batteries, it is done, usually, by a well qualified designer, who takes all the ramifications into consideration, and the assumption is made that the system will be worked on by qualified staff.  When a model boat is being built, and a deviation from the manufacturers instructions is under way, the modeler becomes the designer, if all goes well, great, but there is plenty of chanced for poor performance, a damaged model, and even worse, a damaged modeler.

[wingertaz]

Well put Malcolm

Regards Gary

[Stavros]

having seen the damage a sealed lead acid batt that went BANG in an alarm systen recent I certainly WOULD NEVER charge a batt in a model NOT even with the deck hatches taken off.Lets put it another way DO you really value your pride and joy,I DO. My batts are now charged in a separate room to the boats and on rubber mats with plenty of air around them,my theory is BETTER SAFE THAN SORRY


Stavros

[sheerline]

Just my tuppenceworth, Wombats suggestion of using diodes when parallel wiring of batteries is a very valid point. In an ideal world, batteries would always be identical but the reallity is they are not and if they have differing internal resistances there will be acurrent drain from one pack to the other, it may be slight but it will cause a drain. There is also the problem of one battery failing which can also cause a much heavier discharge from the good battery. The fitting of diodes eliminates any of the possible problems associated with parallel wiring. For a belt and braces approach to safety, I would also recommend the fitting of individual fuses to each of the batteries to avoid a possible fire should a catastrophic failure of one battery occurr.
Although some manufacturers may recommend upright positioning of cells during charging, this is an ideal to avoid any possible problems with electrolyte having found its way around the base of the rubber vent caps and being expelled due to possible pressure build up. The gel electrolyte in normal consruction of the cells is usually well contained and formed around the plates so this is exceedingly rare and we have never seen it in all the time we have been using these types of cells.
Always ventilate when charging but also note that it is imperetive you do not exceed the normal charge rates for these types of cell as their type of construction does not permit the abuse meted out to the 'wet' cell types. If you tend to abuse your batteries (we've all done it at sometime) then all the more reason for fitting diodes AND fuses!
Chris
 

[Mr Whoppit]

owch

[John W E]

--------------------------------------------------------------------------------
hi there all

To be honest with you, linking batteries in parallel wiring, or in series for our use in models, I do not see it making any difference in the performance.   I have several models which I do this with, where the batteries are linked up together in one way or the other, for different amperages and voltages and one of the worst problems I have found/had was on HMS Ajax; it was the actual battery casing that had split.  These batteries I had bought from Ebay and they looked like they were ex-military stock when I received them and the sides of the battery casings where it had been moulded had like a large recess in it, which has eventually split and you will see where I have done a temporary repair to try and stop the innards from falling out.   These batteries are now to be binned.   

Also, one of these batteries, did explode and split its casing in the MTB that I use - when I say Explode it was fizzing it had split where the dimple was - I have included a couple of photographs to show you how I instal the offending batteries in HMS Ajax - as you can see they sit inside two separate holders; which I can slide in and out of the hull.   

I normally charge batteries when they are outside of the hull for safety reasons.

In some models though, its not feasible to have the batteries standing upright.  In my present build of the Cervia the battery will be lying on its side flat.

aye
john e
bluebird

[andi4x4]

Don't know if it is of any relenence here, but, my Honda motorcycle has a sealed lead acid battery fitted - on its side in the correct position in the correct battery box designed by Honda. Obviously this charges on the bike whilst riding and has been fine for nearly five years. Can't put a normal lead acid battery in it - for obvious reasons - so I would figure that the batteries being used/discussed here should be fine so long as they are not being charged at rediculously fast rates.

Regards

Andi

[FullLeatherJacket]

I think that the original caveat about parallel connection was made in relation to packs of multiple NiMH or NiCAD cells, where there is much more likelihood of a mismatch between packs and all that could follow.

I would have no hesitation in operating two SLAs connected together in parallel, assuming that they were of the same voltage and capacity. They should always be charged separately, however.

As for charging in the model, it makes sense to me to remove them if only because I have a memory like a sieve; viz the sight of several batteries sitting on the bench would be more likely to remind me to switch them off-charge than a boat sitting in its usual place with just two wires trailing out of it!

FLJ

[Martin (Admin)]

 

"They should always be charged separately."
  This can't be stressed enough, UNLESS YOU HAVE A CHARGE DESIGNED TO DO THAT TYPE OF CHARGING!
    It can be dangerous or at least very expensive attempting to charge batteries while still wired together!

The reasons are, attempting charge batterries in parallel and one battery fails, your charger may not understand and try to continue to charge at maximum current into the good battery thus overcharging it and distrying it. Likewise, don't attempt to charge batteries in series for the same reasons. Some people and get away with but more by luck than judgment!

I ALWAYS recommend a fully automatic battery charger , the ones with adjustable setting are best and don't skimp on the cost.
Make sure that your charger has a specific setting for the battery you're charging, ie. Lead Acid, NiMi, LiPo, NiCad, NiMH
.... I've got too many dead (ballast) batteries around here that testify to cheap chargers.  >:(

[malcolmfrary]

I go along with not charging in parallel - there are too many things that can go wrong and creat further serious trouble. 
When you think about it, we do charge in series as a a matter of course.  A 6V SLA has three cells in series, and no way to change that.   If charging two 6V batteries of the same capacity that are normally used connected as a 12 V battery, they should always be in a similar stae of charge/discharge, and this can be checked with a voltmeter.  A 12 volt charger will be just fine in this case.
HOWEVER, if the batteries are not used as a pair, they should always be charged separately with an appropriate charger.

[banjo]

 

Upright or flat

I opened this thread because I thought it was about pianos.....

Stupid or what!!