dweeze
Well-Known Member
Hi - can anyone tell me whether running an equalisation over a bank is ok - or whether each individual battery in the bank needs doing seperately?
Thanks
Thanks
Desulfating batteries
- Thread starter dweeze
- Start date
SvenglishTommy
Well-Known Member
It's fine to do it on a bank, unless the bank is huge. What are you using to perform the equalisation?
billcowan
Well-Known Member
what the fook are you guys talking about?
All us other plonkers would love to know
All us other plonkers would love to know
david_bagshaw
Well-Known Member
Equalisation charge is where a higher than normal charge voltage is applied for a limited period in a pulsed manner, one of the benifits being it "breaks off the sulphation frome the plates" I believe.
Salty John
Well-Known Member
Equalisation is a controlled over charging to get rid of sulphated areas on the battery plates. You drive the battery voltage up as high as 16v. If you don't do this the sulphates harden and the battery capacity is reduced. You need to monitor the process carefully so as not to cook the battery. I try to do it regularly but it is difficult to say if it has any significant effect on battery life.
dweeze
Well-Known Member
Thanks for this. I've got 3 x 8D in one bank and 2 x 8 D in the other. Both connected in parallel. I was thinking of doing both banks seperately - but if this wasnt ok then the only option was to try and figure out how to do each battery seperately. I've got a choice for equalisation. Either through the Aqualine external reg or through the Heart Inverter off shore power. You have an opinion on which would be better?
I had read that equalising banks in series was ok but ones in parallel would open up the possibility that one might end up with a different level of de-sulphated'ness than the other.
tim
I had read that equalising banks in series was ok but ones in parallel would open up the possibility that one might end up with a different level of de-sulphated'ness than the other.
tim
Ships_Cat
Well-Known Member
It is fine over the bank as long as the equalisation voltage is maintained (and don't forget to isolate all equipment from the batteries first to avoid the possibility of damage to it). One assumes your batteries are wet celled not AGM or similar.
However, in my opinion, it is hardly worth the trouble equalising batteries and commonly battery manufacturers do not make any point of recommending it. I personally do not know anyone who equalises their batteries and none of my commercial clients do. The sulphates only build up in thick plated batteries when the batteries are not regulalrly brought up to full charge (and the charging systems on many yachts are incapable of doing so /forums/images/graemlins/frown.gif). Once the damage is done and the sulphates have hardened then you are stuck with it so the method is to avoid it in the first place.
On our own boat we use the following regime - the batteries are always fully charged immediately after each discharge (ie never left partly discharged) and only discharged a maximum of 50% capacity. They are charged by an alternator large enough to get them to full charge within reasonable engine run times and they are maintained at full charge at float voltage of 13 point whatever by solar when the boat is not attended. We run the engine for at least an hour a fortnight all year round with batteries at full charge at the start of the run (good for the engine too) - our charge controller for the main alternator is one that will maintain the bulk 14 point whatever you have volts for that hour down to low charge rates so charge is deep (whereas our shore power charger drops back to float voltage very quickly).
Our last house set of batteries had a useful life of 9 years under that regime. On solar sites I am familiar with, where the batteries suffer very deep discharges on occasion (sometimes to flat) and are cycled to deep discharge daily, a life of 6-7 years is usual before they fail a load test (ie battery still usable, but capacity reduced below the site's requirements) and they are never equalised.
John
However, in my opinion, it is hardly worth the trouble equalising batteries and commonly battery manufacturers do not make any point of recommending it. I personally do not know anyone who equalises their batteries and none of my commercial clients do. The sulphates only build up in thick plated batteries when the batteries are not regulalrly brought up to full charge (and the charging systems on many yachts are incapable of doing so /forums/images/graemlins/frown.gif). Once the damage is done and the sulphates have hardened then you are stuck with it so the method is to avoid it in the first place.
On our own boat we use the following regime - the batteries are always fully charged immediately after each discharge (ie never left partly discharged) and only discharged a maximum of 50% capacity. They are charged by an alternator large enough to get them to full charge within reasonable engine run times and they are maintained at full charge at float voltage of 13 point whatever by solar when the boat is not attended. We run the engine for at least an hour a fortnight all year round with batteries at full charge at the start of the run (good for the engine too) - our charge controller for the main alternator is one that will maintain the bulk 14 point whatever you have volts for that hour down to low charge rates so charge is deep (whereas our shore power charger drops back to float voltage very quickly).
Our last house set of batteries had a useful life of 9 years under that regime. On solar sites I am familiar with, where the batteries suffer very deep discharges on occasion (sometimes to flat) and are cycled to deep discharge daily, a life of 6-7 years is usual before they fail a load test (ie battery still usable, but capacity reduced below the site's requirements) and they are never equalised.
John