Battery question..

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mikecontessa26

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I've currently got two Rolls 80amp deep cycle batteries, one has started hissing which carries on for a few hours at least after charging, i've had the batteries 5 years and they've been punished a bit to be fair, left in the boat without being charged for two periods of over 6 months while I was living in Australia.

Am I right in thinking they've had it? I'll probably replace like for like and treat them nicely this time.

Thanks Michael
 
Hissing?
When not on charge?
That's a new one on me.
What are you suggesting it is?
Not a good idea just to replace one at this age and history.
 
no idea what it is... it hisses only after charge but ive never stuck around long enough since the problem to hear it stop, 2-3 hours. Maybe over-charging when it's hot, using sterling charger though so? water levels are and always have been ok, plates don't look too bad, obviously not brand new.

I have the opportunity to ship one out with all my other stuff for the summer, and worry if i don't i'll end up buying one locally at stupid prices
 
mikecontessa26 said:
no idea what it is... it hisses only after charge but ive never stuck around long enough since the problem to hear it stop, 2-3 hours. Maybe over-charging when it's hot, using sterling charger though so? water levels are and always have been ok, plates don't look too bad, obviously not brand new.

I have the opportunity to ship one out with all my other stuff for the summer, and worry if i don't i'll end up buying one locally at stupid prices
Click to expand...

It sounds as if you have 2 x Rolls 80amp 4000 series batteries. Are they linked as one 160 Ah domestic bank? Anything special about the caps? Could one set be blocked up, causing the battery to pressurise? Hissing for 2-3 hours after charging sounds odd as that would involve quite a lot of hydrogen under pressure to be audible for that length of time. Pity you didn' check the voltages individually, that would have been very useful. Sounds as if there might be an internal short on one battery as that would cause it to generate a lot of gas when charging. However, I'd have expected you to hear it fizzing soon after you begin charging.

I replaced all my batteries before leaving UK as that was cheaper than leaving it until I just had to buy anything I could get my hands on. So appreciate your dilemma and would be tempted to take 2 as 2nd one might give up soon if it's the same age.
 
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Yes thats the batteries, linked as 160 amp as mentioned, when i was charging the batteries it was very hot in the boat, around 40 degrees i'd say but i went back later in the year and the same thing happened when it was much cooler. The batteries had held a charge of around 11 volts each after 3 months of self discharge and being totally un-plugged. I check each individual voltage after charging and each read 12.5ish volts, nothing different between the two.

the caps are normal and the sound isn't so much as a hiss but could be a shorting sound as it's intermittent almost a buzz? Not constant. It's even present when there is nothing connected to the batteries so not wiring related.
 
11 volts is pretty flat in my book - but others might have differing interpretations. Under some discharge regimes a lead acid battery can go as low as 9 volts or so but running a battery this flat is VERY BAD for the battery.

Be careful of the tests that local battery shops do. They will test for voltage under cranking amps and that isn't what you need to know.

The real answer is that they are probably at least partially destroyed by the abuse they have received. However if you can get them off and FULLY charge them (or at least charge them until they won't take any more) then you can do a capacity test which is much more informative.

Fully charge them and then connect a load (say a couple of car headlamps) and monitor the voltage. Hours of discharge before they are flat multiplied by the amps that the bulbs are drawing gives you a capacity 'at that discharge current'. It will give you a very good idea of what capacity they have for the loads you are pulling off them. Use a hydrometer to check what state they are in as they being discharged...
 
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Thanks for the responses... to be honest during my last season they were not holding charge as well as i'd expect, i think i'm going to bite the bullet and replace them. I plan to live on the boat for 4 months this year and don't want to risk it. Lots of money though :(

Are Rolls still a good choice for a wet deep cycle? Most of the forum searches come up with AGM vs Wet acid threads, I can't afford AGM.
 
If you want to stay with flooded batteries then you will struggle to beat 6V golf buggy batteries. These are widely regarded as good value for money. Someone will no doubt persuade you to buy AGM as the total cost is less. I did the calcs for my own system and Trojan T-105s were the cheapest option (including fuel to recharge, usage, lifetime etc.). Might be different for yuor system if you run the engine just to re-charge.

I paid about £1.025 /Ah for my T-105s, so 2 would cost around £230 for 225Ah if still available at same price. You'd get 40% more capacity than existing set-up but space (and correct battery orientation) might be an issue.

I'm assuming that you fitted Rolls deep cycle as you spend a lot of time away from shorepower. T-105s make sense if that's the case.
 
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Unfortunately the Trojan T105's will be too high, my Rolls are quite snug in the compartment as i made it to measure. Yes i spend a lot of time away from shore power, anchorages mainly. I tend to have to run the engine every couple of days, I have a Weaco compressor fridge taking 2.5 amps all day. Had no solar for the last season but fitting 100amp panel this year.
 
mikecontessa26 said:
Reading this is making me think i should avoid Rolls... or maybe i need to buy Rolls AGM :( http://www.ybw.com/forums/showthrea...rden-UK-and-Rolls-Deep-Cycle-Marine-Batteries
Click to expand...

Size might still be a problem. I searched for suitable batteries to fit the space I had and finally decided to lower the floor in the battery compartment. Sealed flooded batteries ranged from 70%-100% cost of T-105s and decent AGMs were hugely expensive (even allowing for fact that I'd get away with less Ah capacity).

I was luck on 2 counts, plenty of room under the existing box and T-105s weren't as tall as advertised.

Spec:..........264 x 181 x 284
Measured:...261 x 181 x 270
So height was 270, not 284 as advertised when I ordered them.
 
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mikecontessa26 said:
I've currently got two Rolls 80amp deep cycle batteries, one has started hissing which carries on for a few hours at least after charging
Am I right in thinking they've had it? I'll probably replace like for like and treat them nicely this time.

Thanks Michael
Click to expand...

You've got one good battery and one duff one......after charging, the charge from the good battery is transferring across to the bad one causing it to bubble, as it would if it was on charge.

Disconnect them, and charge them seperatly to find out which is the good one..........
 
Westerly Jetstream said:
12.7 fully charged.
12.4 75% charged.
12.2 50 % charged
12.0 25% charged.
11.9 DEAD.
Click to expand...

That's a pessimistic table:
Here's data from Yuesa
Temperature: 67 degrees Fahrenheit
Percent Hydrometer Unloaded
charge reading voltage
100 1.262 12.61
75 1.207 12.28
50 1.157 11.98
25 1.117 11.74
0 1.097 11.62
the voltage is temp dependant.
 
rustybarge said:
You've got one good battery and one duff one......after charging, the charge from the good battery is transferring across to the bad one causing it to bubble, as it would if it was on charge.

Disconnect them, and charge them seperatly to find out which is the good one..........
Click to expand...

+1 You probably have one dead and one good. Yes take one new battery but don't just parallel them and forget. Separate and check voltage and apparent capacity and starting capability often.
Went to Australia? you were luck not many sailors return from Oz to UK. if a dead battery is your punishment you got off lightly. good luck olewill
 
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