RodC,
SLA batteries should be in the upright position during charging so that any gases created during the charge can escape. I suggest that you check the web sites of battery manufacturers such as Power-Sonic, which have in depth explanations regarding charge positions, rates and discharge rates.
SLA's are wonderful batteries, but like NiCD's, NiMH, and Lithium batteries they require proper care for long life.

Stephen,
John is right on the money, but I would add one important thing. SLA's (sealed lead acid) batteries are not completely "sealed". They have a vent on the top of them to allow gases built up to escape. It is important to bear this in mind when charging the batteries. If not, the gases can build up in the the batteries will lose some of their capacity and, worst case, can explode. Easy way around this, which many folks adhere to, is to remove the battery from the model and set it correct side up while charging.
Hope this helps.
Jonathan

12Volt LP-7 batteries need not be kept "uoright" while being either charged or discharged. There is no liquid electrolyte to pour out of the vents.

If one chooses to use a "motorcycle"-style lead acid battery, with liquid electrolyte (it will hav screw-on cell caps) then the battery must be kept upright at all times.

Here is my 12v 7ah battery in my Sea Commander, laying flat under centre well deck.
Cheers Colin.

thanks for the info mine are the 12v Lp7 types and laying flat would be great for ballast i was told these alarm batteries need to be upright

Having read this thread right through I agree with all that has been said except there is a new type called LiFePO4, same physical size and same or greater ah. But half the weight.
As an old school modeller I have used lead acid batteries since the 1960's and I am still relying on them as my main power source.
But now as I replace them I have started using LiFePO4 batteries.
Cheers Colin.

I hav been using SLA (Sealed Lead Acid) batteries since 1972 both professionally & as hobby batteries. I concur with all of the earlier remarks. In my experience the situations of outgassing, leakage, & battery failure hav resulted from OVERCHARGING, either thru excessive voltage being applied from the charger, or excessive charge current. Simple chargers often lead to problems as they are unregulated, simple devices, designed to meet an inexpensive price point.

A safe charger for a 6V SLA supplies a max of 7.4V, voltage regulated, max current 1.35A to a 4.5Ahr battery....so a minimum recharge time is approx 4 to 5 hr. For a 12V SLA the max wud be 14.8V (this # suggests, BUT do not use a charger intended for a standard lead-acid car battery)

SLA has several advantages for the model sailor: relatively inexpensive, very available in a variety of physical sizes, standardized terminals, can safely be charged without removal from the model, serve as ballast, & can be safely connected in series or parallel without using isolating diodes.

Yes, I do use LiPO's in certain vessels,for lighter weight,longer runtime,but remove them to protective bags for charging & storage,then reinstall immediately befor a run. In comparison I hav found SLA to be relatively carefree.

My years of experience with NIMH in model aircraft have also taught me that they are an inexpensive, lightweight, easily-managed option.

Stephen,
John is right on the money, but I would add one important thing. SLA's (sealed lead acid) batteries are not completely "sealed". They have a vent on the top of them to allow gases built up to escape. It is important to bear this in mind when charging the batteries. If not, the gases can build up in the the batteries will lose some of their capacity and, worst case, can explode. Easy way around this, which many folks adhere to, is to remove the battery from the model and set it correct side up while charging.
Hope this helps.
Jonathan

There are two types of Acid Batteries, 1- the WET ACID batteries( in cars), and 2- SEALED LEAD ACID(SLA) known as Gel Cells. As the name implies, these have the acid in a gel, and the batteries are sealed allowing them to be placed in any position.
Gel Cell Batteries are great for any larger, displacement hull models, where weight is often required to trim the boat down to the waterline. You can add multiple batteries as needed simply by wiring them in parallel, to keep same voltage, but adding up the storage amperage, basically giving you more run time.
See pic of one of my setups with two Gel Cells laying flat.

Hi Steven,

Concerning lead acid barreries, almost all model boaters now use the sealed 6 or 12 volt SLA of "Jelly" cells. These may be mounted in any orientation within the model without problem.

If however you are talking about motor vehicle (car or motor cycle) batteries containing liquid sulfhuric acid, - these must of course be kept upright at all times!!

Regret I cannot understand your point 're parallel or series MNIC cells. In parallel these will remain at 1.2 volts whereas in series they will produce the total of all cells so wired.
With best wishes John. 🤔🤔