# Leisure Battery Venting



## mrblitz (Nov 21, 2009)

I have a bank of six 65ah Yuasa sealed 12v batteries.

I got them for £10 each (rrp £140+ !!!!!) and they are ace.

They are totally sealed lead acid batteries that are designed to work in any orientation (except inverted). I am aware that no matter how 'sealed' a battery is, it will still vent some hydrogen sometimes.

With this in mind, and the fact that i have two high output 3-stage charging units (a 90amp Sterling 'alt. to batt.' charger when in motion, and a 25amp Muvonics Amperor when on hook-up), what sort of ventilation should i be looking at for this battery bank?

They are situated in box under a bench seat, air sealed from the living space. They sit two high, in three stacks with about three inches between each stack.

I was thinking of drilling four 10mm holes down through the floor between each stack, eight holes in total, and fitting a shielded vent 100mm x 40mm to the outside up above the top of the batteries.

Will this suffice? Or should i be more trigger happy with my drill?


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## philoaks (Sep 2, 2008)

I'm no battery expert but I always thought sealed was "sealed"


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## clive1821 (Mar 27, 2010)

With my limited experience of Yuasa batteries, I only use them on my stand by systems, I would not even bother with venting.... they should be fine as they are, with that much capacity I would be more concerned with protection ie fusing them to prevent damage to your van in the event of a fault... which is far more important. You did mention that these batteries were not in the living area. I assume that you have a large requirement of 12v supply? if the answer is yes fine if not the charging you are using might be an over kill... still be interesting to see what you do...


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## clive1821 (Mar 27, 2010)

one thing I did not mention make sure the charge rate is correct... it will say on the side of the battery if in doupt, check on the RS data base I do recall that I had to reduce the charging current on one of the types they provide and there are several different types...


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## mrblitz (Nov 21, 2009)

Thanks Clive. You are the first person i have encountered with any experience of Yuasa batteries, though they seem to be very well reviewed etc on the web.

Our 12v requirements are a little unusual. We are going to be living full time in our van, in a remote area of France and most of the time with no hook-up available. We will be mostly relying on our Sterling for our power source as we will be driving at least 60 minutes every other day. We will be using a generator for a few hours in the daytime if need be, hence the large amperage charger. On the odd occasion that we do visit a camp site we may not have to bother with paying for electric.

Is there an issue with 'cooking' batteries if i were to leave the mains charger running too long? Surely the charger will stop charging if the batteries are full? The Sterling has a specific mode for sealed batteries and outputs a lower charging rate and is more sensitive to battery temperature increase (it has two temp. sensors, one goes to the alternator, and one to the leisure bank). The system will shut down of either get too hot. If this becomes an issue i can fit an old truma tb fan via a 1m duct as an air cooling system for the battery locker. That way eliminating any danger caused by sparking, though you suggest this may not be a problem.

With regards fusing...our total draw on our system will be max 50amps with everything on. The cables i am using are 30mm sq, should i fuse at 60 amps in between every battery? Or just at each end of the supply runs? The cable distance between each battery will be under six inches. Maybe i should fuse in between each stack? Sorry for the stack of questions.

The Yuasa battery model is NP65-12I. Can you suggest somewhere i can find some info that will help me with charging info etc, as i can only seem to find site selling these batteries. There is almost no info at all on the side of the casing. Just the model number, battery type and a notice to avoid storing in a gas tight container and to avoid shorting. Wise words.


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## clive1821 (Mar 27, 2010)

Uuumm ok now I understand.... I would have gone down the solar panel route... and put 2 x 120 units on the roof and that would be a little kinder on the batteries.... its not a good idea to rapid charge these batteries and if i recall 13.30 volts is the max volts you should apply to them... with regard to fusing... if all the batteries are contained in either a plastic container or wooden one I would only fuse at the output of the "battery pack" if they are connected together (I would use 10mm cables) and if theres any chance of a short I would indeed fuse them individualy (as you have a vast amount of current in a battery in a fault condition)... and then use 30mm cable to your distribution point depending on the distance... the main "battery pack" fuse I would not use more than 60amp blade fuse.. then when the supply is distributed fuse the supply cables at the recommended ratings of the cables.... this subject can go on and on with various opinions that conflict lol... but this is my view... better to be safe than sorry I say... if you really need rapid charge batteries go down the AGM types as they are very forgiving... at a price of course!!! i have a yuasa document but have not found a way of attaching it to this post.. must have a paly with that sometime... good luck... hope that helps a little


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## mrblitz (Nov 21, 2009)

We were hoping to get a couple of 80w panels but our project ran away with itself and our budget wouldn't cover, em. Maybe in the future.

Thanks for your help.

My voltage options via the sterling are either 14.4v designed for sealed batteries (with a short absorption time) or 14.1v designed for gel batteries. I am assuming that the 14.4v sealed battery charge coupled with shorter absorption time will suit the Yuasa batteries more than the lower voltage gel mode, due to the absorption issue. Once full charge has been reached the unit drops to a standard 13.6v float charge.

The temp. monitor will give me an additional safety measure when charging from the sterling. Hopefully the 25amp mains charger will not pose any problems.

I don't really have an option to change my batteries now, so i'm just gonna have to go crazy with fuses and keep a close eye on things until i'm happy that all is well.

I will fuse in between every battery for safety. As well as fusing the final output to the distribution board. 60amp fuses all the way.

Is 30mm sq cable between the batteries a bad idea? I have loads of it, but could easily get some 10mm sq if that will be a better option. I always thought that as long as the fuse is lower than the cable rating all is good.

Thanks so much for your time and brain.


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## clive1821 (Mar 27, 2010)

yes fine on the 30mm cable just very thick thats all, i was thinking of connecting the batteries together.... my view is that the yuasa range are not to happy to be charged with heavy currents, the end result will be battery plates going faulty at a stage and not producing any current. If I can be any more help please feel free to PM me...


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