how do you equalise your batteries?

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GHA

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with a sterling mains charger with no setting to get up to 15.5v how do people equalise their batteries?

going on the likes or trojan/rolls et al who suggest around 15.5v or a c/20 current I'm a bit stumped without going the whole hog and investing in something like..

http://www.ebay.co.uk/itm/Adjustabl..._Measurement_Equipment_ET&hash=item485b5aee9a

which actually isn't that much considering 400 quid odd for 4 trojan t105's

solar/wind is just too variable , any other suggestions?

tia
 
Why 15.5 volts? Seems excessive to me - I thought that 14.5 was normal. If by equalise you mean get them both [all?] to the same state of charge then surely the back emf of each battery will take care of that - the more fully charged the battery the higher the back emf. and so the lower the charging current.
 
reeac said:
Why 15.5 volts? Seems excessive to me - I thought that 14.5 was normal. If by equalise you mean get them both [all?] to the same state of charge then surely the back emf of each battery will take care of that - the more fully charged the battery the higher the back emf. and so the lower the charging current.
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15.5 - 16v seems to be the manufacturers recommendation.

http://www.rolls-battery.com/conten...cf0f71e01d23&phpMyAdmin=9dec4a269d70t7a63be7c

http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx
 
GHA said:
Looks like it uses pulses for desulphation. I should have mentioned in the first post that equalising will often need to be done at anchor, either with a genny or solar/wind if there's a controllable method.
Click to expand...

It does the desulphation on every cycle, just for a few seconds. It also has a manual equalise mode.

To reliably equalise you will have to use shore power or the generator.
 
GHA said:
with a sterling mains charger with no setting to get up to 15.5v how do people equalise their batteries?

going on the likes or trojan/rolls et al who suggest around 15.5v or a c/20 current I'm a bit stumped without going the whole hog and investing in something like..

http://www.ebay.co.uk/itm/Adjustabl..._Measurement_Equipment_ET&hash=item485b5aee9a

which actually isn't that much considering 400 quid odd for 4 trojan t105's

solar/wind is just too variable , any other suggestions?

tia
Click to expand...

I bought one of these for not too much money. www.amazon.co.uk/Megapulse-12-V-battery-pulser/dp/B002BZE13Y
It seems to do something as batteries remained good.
 
GHA said:
with a sterling mains charger with no setting to get up to 15.5v how do people equalise their batteries?

going on the likes or trojan/rolls et al who suggest around 15.5v or a c/20 current I'm a bit stumped without going the whole hog and investing in something like..

http://www.ebay.co.uk/itm/Adjustabl..._Measurement_Equipment_ET&hash=item485b5aee9a



which actually isn't that much considering 400 quid odd for 4 trojan t105's

solar/wind is just too variable , any other suggestions?

tia
Click to expand...

My Sterling switch-mode charger does have an equalising phase which puts in up to 15.0v for anything from 30' to 4 hours after the bulk phase. It doesn't do any of that fancy desulphation pulsing though. I bought it direct from them as a "redundant stock" item for about x2 the unit in the above link. All on timer and no feedback, 20v with 3 outputs. I really only bought it because it was small enough to substitute for the Italian "Shark" switch mode charger which decided to blow its transformer
 
nigelmercier said:
To reliably equalise you will have to use shore power or the generator.
Click to expand...
Why is that?

Thinking about it a bit more, there would be plenty of power on a breezy sunny day if somehow it could be controlled, why not an adjustable solar/wind regulator, if such a thing exists.

It would be nice to have some control over the voltage anyway, trojan recommend 14.8v, the regulators I've seen are fixed lower than that.
 
GHA said:
Why is that?

Thinking about it a bit more, there would be plenty of power on a breezy sunny day if somehow it could be controlled, why not an adjustable solar/wind regulator, if such a thing exists.

It would be nice to have some control over the voltage anyway, trojan recommend 14.8v, the regulators I've seen are fixed lower than that.
Click to expand...

Sterling Alternator to Battery Charger has an equalisation (desuplhation) mode and different settings for different types of batteries. Can also accept input from other sources so if you had reliable sunny/ windy day I don't see why you couldn't do it. As others have said though, do it at anchor / when moored. The voltages mentioned may cause damage to instruments etc so would be brave to leave them in use whilst equalising.
 
jac said:
Sterling Alternator to Battery Charger has an equalisation (desuplhation) mode and different settings for different types of batteries. Can also accept input from other sources so if you had reliable sunny/ windy day I don't see why you couldn't do it. As others have said though, do it at anchor / when moored. The voltages mentioned may cause damage to instruments etc so would be brave to leave them in use whilst equalising.
Click to expand...
Looks like just multiple alternator inputs, 13v - 13.5v unfortunately. Nice unit though, pricey!
 
reeac said:
Why 15.5 volts? Seems excessive to me - I thought that 14.5 was normal. If by equalise you mean get them both [all?] to the same state of charge
Click to expand...

14.5 is normal charging, 15 or 16 is equalising. And no, equalising doesn't mean charging the batteries equally.

The documentation for proper deep-cycle wet batteries (as opposed to Halfords leisure batteries) explains the maintenance needed.

Pete
 
nigelmercier said:
Because the voltage has to be sustained for up to several hours and stable.
Click to expand...
Just a question of control then, given the right weather.

Where to find an adjustable regulator.

And generally looking into this more it's hard to see how effective *any* staged regulator (alternator or solar/wind) can be on a cruising boat, it has no way of knowing how much current is going into the batteries and how much is getting used by domestics. Much better to have the option of controlling it yourself.
 
>15.5 - 16v seems to be the manufacturers recommendation.

The Trojan site says charging is 13.8 to 14.4v with a float charge of 13.5v. That's the level we charged our Trojans at and never had sulphation problems
 
KellysEye said:
The Trojan site says charging is 13.8 to 14.4v with a float charge of 13.5v. That's the level we charged our Trojans at and never had sulphation problems
Click to expand...
This is a different issue.

Mode ”RECOND” (15.7V, 1.5A 0.5–4h)
This mode is used to recondition very discharged batteries where you could expect a stratified
acid (high acid weight in the bottom, low on top). Use this mode with care because it can cause
some water loss. 15.7V is normally not a problem for electronics, but consult the manufacturer
when in doubt. Life of light bulbs can be reduced by higher voltages. Try to avoid using 12V
lamps connected to the battery during this phase. Maximum effect and minimum risk for
electronics is achieved by disconnecting the battery before charging.

...

Chosen mode: ”RECOND”
M100 has a Recond mode which is used to recondition a battery that has been severely
discharged. The battery is first charged using the mode ”NORMAL”. When the analysis phase is
complete, the charger begins reconditioning the battery by providing a constant current of 1.5A
and a maximum voltage of 15.7V. After 0.5–4 hours, the battery is completely reconditioned
and the charger goes into pulse maintenance. The battery is ready to be used, or store it with
pulse maintenance active until you are ready to use the battery. Recond is indicated by lamp
E and lamp 6. Note that the recond phase begins with normal charging and that the charger
therefore will indicate the charging phases according to the descriptions above first. Lamp 6 is
first lit when the reconditioning begins.
 
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nigelmercier said:
Do you know how to calculate the required settings then? How are you going to measure what is required?

The process is explained in "page" 5 of this document, based on the charger I linked to in #3
http://www.ctek.com/Archive/ProductManualPdf/M 100_EN.pdf
Click to expand...
For equalising that's different from recommendations by the likes of trojan etc, high voltage, keep an eye on the water and heat levels, process is done when SG of each cell is very close. Current seems commonly to be recommended to be limited to C/20, ie 5A for a 100Ah battery.
 
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