Alternator charge level

[bob ellison]

I have a Beta 43 with an Iskra 175 amp alternator (charging at 14.8 volts). I have / had 5 x 135 amp Multicell top up batteries. After no more than 150 engine hrs my battery bank is useless. Multicell say one battery is duff. My builder (Kingsground) have agreed to replace all 5 batteries under their own warrenty as a good will gesture. I now have to decide what batteries/make and toal capacity to replace them with. Speaking with various "specialists" it appears that part of the cause of very short life of my battery bank may be down to the charge voltage at 14.8 volts from the alternator. I undertand this will damage the batteries when a nearly a full charge is reached.

 

I favour AGM's as replacements but have been advise AGMs aren't very tolerant to high voltage charge (14.8) at the end of recharge. one "specialist" says they'll be knackered very quickly! We use a maximum of 100 amps per day and as back up charging we have 2 x 130 (260) watts of solar panels up top.

Is there anyone out there with a similar problem?

[bottle]

Hi Bob

 

Welcome.

 

We have many 'experts' on here (I am not one) but I would contact Beta and check whether the alternator should be pushing out 14.8 v, which is on the maximum side for wet cell (standard/normal) batteries.

 

AGM, Gells etc need different (lower) voltages.

[jelunga]

I have a Beta 43 with an Iskra 175 amp alternator (charging at 14.8 volts). I have / had 5 x 135 amp Multicell top up batteries. After no more than 150 engine hrs my battery bank is useless. Multicell say one battery is duff. My builder (Kingsground) have agreed to replace all 5 batteries under their own warrenty as a good will gesture. I now have to decide what batteries/make and toal capacity to replace them with. Speaking with various "specialists" it appears that part of the cause of very short life of my battery bank may be down to the charge voltage at 14.8 volts from the alternator. I undertand this will damage the batteries when a nearly a full charge is reached.

 

I favour AGM's as replacements but have been advise AGMs aren't very tolerant to high voltage charge (14.8) at the end of recharge. one "specialist" says they'll be knackered very quickly! We use a maximum of 100 amps per day and as back up charging we have 2 x 130 (260) watts of solar panels up top.

Is there anyone out there with a similar problem?

 

Do you know how low a state of charge these were allowed to get to before recharging? This is much more likely to be the cause of their early demise.

Symptoms of overcharging would include significant gassing, which you could see by cell acid levels getting low quickly and the need for frequent topping up.

 

Have you noticed such symptoms?

 

However, there are those on this Forum far more expert than I in these matters, and they should be along soon.

 

However, they are like buses. You wait and wait and then 2 or 3 come together.

 

Gibbo, where are you?

[Chalky]

I use AGMs and a battery specialist I work with advised me strongly to keep the voltage below 14.8. I charge mine at 14.4. Ask Gibbo - he'll know.

[ditchcrawler]

I have a Beta 43 with an Iskra 175 amp alternator (charging at 14.8 volts). I have / had 5 x 135 amp Multicell top up batteries. After no more than 150 engine hrs my battery bank is useless.

You say 150 hours engine hours how does that compare with days of battery use. I.E is it 75 days at 100 ah per day or 30 days.

[NB Willawaw]

The normal output from these alternators is much lower - usually 14.2 - 14.4V.

 

How do you know that the output is 14.8V and do you have a battery controller fitted ??

[bob ellison]

The normal output from these alternators is much lower - usually 14.2 - 14.4V.

 

How do you know that the output is 14.8V and do you have a battery controller fitted ??

[bob ellison]

Hi to all responders,

14.8 amps is the quoted Iskra output but cos I'm new to all this and not on Jam Pudd til march I'm unable to say if that's what's being pumped out. I wasn't specifically checking this read-out on the battery monitor. The Victron Inverter guide says that the SOC read-out is the critical figure to monitor. Later I was advised thet the most important read-out to watch on the monitor is the voltage left in the battery bank AND not to let it drop below 12.2 volts. (being about 50% realistic SOC.) Most times when I checked what the readings at 12.2 volts the SOC was showing above 85%! I'm also now told that after recharging to 100% I should note amps out then make sure that I recharge same amount back in PLUS 20%!

 

My main purpose in posting this item is that I'm looking for guidance from the "experienced" on what steps I should take to aviod a repeat with AGM's and this 14.8 volt/175 amp alternator. We use a max of 100 amps in any one day so what size bank should we buy and what suggestions have you to recharge at a lower voltage?

Thanks for responses one and all.

Bob

NB Jam Pudd

[NB Willawaw]

A constant 14.8V output is not healthy.

 

I would suggest that the first priority is to get this checked to ensure that the regulated output really is this high.

 

Assuming that this is erroneous and the alternator is outputting something more sensible, then choosing a suitable battery type etc is to some degree a matter of preference (there are lots of different battery types and approaches) and this is well documented on a number of threads on here.

[bottle]

What meters are you using to get the quoted figures?

[nb Innisfree]

Forget the percentage reading on your monitor, it is a shunt based one and becomes increasingly inaccurate, only a Smartgauge can give accurate percentage readings. 14.8v should be at the end of battery charge, battery in lower state of charge will drag voltage down which will increase as SoC increases, at the same time amperage will decrease with SoC increase. We have Multicell AGMs, Multicell recommended a few charges of 14.8 to revive them a bit but I bottled out and stuck to 14.4v, after replacing our alternator I disconnected controller and now charge at 14v, all seems fine and in fact we haven't noticed any difference (actually we are 24v so in our case these voltages are doubled)

[Nickhlx]

We have the Iskra 175 on our Beta 43 and it tops out at around 14.4 Volts ( known to be within 0.1 volts) I am not sure how it varies with alternator temp though - Is the output adjustable on the Iskra ?

 

Nick

Edited December 31, 2010 by Nickhlx

[Iain_S]

Hi to all responders,

14.8 amps is the quoted Iskra output but cos I'm new to all this and not on Jam Pudd til march I'm unable to say if that's what's being pumped out.

(snip)

 

Well worth checking the actual figure. I found a fault on Gamebird (bad connection on the engine earth strap) which raised the voltage across the batteries to 15.5V at times. It is also important to connect the negative of the voltmeter to the battery post........

 

Iain

[bob ellison]

Well worth checking the actual figure. I found a fault on Gamebird (bad connection on the engine earth strap) which raised the voltage across the batteries to 15.5V at times. It is also important to connect the negative of the voltmeter to the battery post........

 

Iain

 

Hi Iain, Thanks for reply. Checking the alternator charge voltage will be done as a priority when I get up to Jam Pudd and before deciding what replacement batteries etc to install.

Cheers.

Bob

 

We have the Iskra 175 on our Beta 43 and it tops out at around 14.4 Volts ( known to be within 0.1 volts) I am not sure how it varies with alternator temp though - Is the output adjustable on the Iskra ?

 

Nick

 

Hi Nick,

Thanks for response. Yes I understand that the Iskra can be adjusted down to 12.4 volts but this is still on the high side (I'm told by "specialists") Sounds like yours has been adjusted. What AGM's do you have; what usage have they had? Any experiences you've had will be appreciated.

Cheers.

Bob

 

Hi Nick,

Thanks for response. Yes I understand that the Iskra can be adjusted down to 12.4 volts but this is still on the high side (I'm told by "specialists") Sounds like yours has been adjusted. What AGM's do you have; what usage have they had? Any experiences you've had will be appreciated.

Cheers.

Bob

[Nickhlx]

Some repetition going on on the forum it seems...

 

I have Trojans - T-125s, 4 off, configured as 12 volts 480 aH with two paralleled pairs of two each in series... These are wet cells.

 

I am sorry, but 12.4 volts can in no way be considered "high" for the average, nominal 12 volt, wet, lead acid battery - I would start off as 14.4 V and give an equalisation periodically of around 15.0 volts. More batteries are killed with undercharging than anything else... and then standby float charging of around 13.2 to minimise positive plate corrosion..

 

Can any experts re-confirm please ?

 

Nick

[bottle]

Bob

 

Your voltmeter will need to be an accuracy of 0.5%. to give an accurate figure,

 

Nick

 

I have Trojans - T-125s, 4 off, configured as 12 volts 480 aH with two paralleled pairs of two each in series..

 

I make that 24v 250ah

 

Parallel pair gives 12v 250ah if you then series the to the other pair it will give 24v 250ah

 

or am I missing something.

 

 

I assume that they are 12v 125ah and disregarded any Peukert effect.

Edited December 31, 2010 by bottle

[Tony Brooks]

We have the Iskra 175 on our Beta 43 and it tops out at around 14.4 Volts ( known to be within 0.1 volts) I am not sure how it varies with alternator temp though - Is the output adjustable on the Iskra ?

 

Nick

 

 

I think you will find Beta are supplying alternators with a 14.8v regulated voltage.

 

This should be OK with Lead Calcium or silver calcium batteries but would probably cause lead antinomy ones to gas. However it should not ruin the lead antinomy ones PROVIDING they are kept topped up.

 

Now, unless you get new batteries from a real specialist I would not trust them to have a clue about the plate technology so with a 14.8 regulated volatge I would go for ordinary open cell batteries and try to get lead calcium ones. At least you can then check and top them up very regularly (boat design allowing ).

 

One major advanced controller supplier is rumoured to have suggested that these alternators have hefty diode fitted in their main charging lead to drop the voltage.

[Nickhlx]

Bob

 

Your voltmeter will need to be an accuracy of 0.5%. to give an accurate figure,

 

Nick

 

 

 

I make that 24v 250ah

 

Parallel pair gives 12v 250ah if you then series the to the other pair it will give 24v 250ah

 

or am I missing something.

 

 

I assume that they are 12v 125ah and disregarded any Peukert effect.

 

Yes - forgot to say that the T-125s are 6V 240aH items

 

Nick

 

I think you will find Beta are supplying alternators with a 14.8v regulated voltage.

 

This should be OK with Lead Calcium or silver calcium batteries but would probably cause lead antinomy ones to gas. However it should not ruin the lead antinomy ones PROVIDING they are kept topped up.

 

Now, unless you get new batteries from a real specialist I would not trust them to have a clue about the plate technology so with a 14.8 regulated volatge I would go for ordinary open cell batteries and try to get lead calcium ones. At least you can then check and top them up very regularly (boat design allowing ).

 

One major advanced controller supplier is rumoured to have suggested that these alternators have hefty diode fitted in their main charging lead to drop the voltage.

 

Presumably, with less than perfect cabling between the alternator and the bank, at anything like the normal "average" charging currents, e.g. 50 amps or more, the voltage drop across the cables will drop the voltage appearing at the posts of the battery bank to nearer what is "correct" ? Coupled with the possibility that most people don't (can't) run the engine for the full required time to replace 100% of the charge, and the last part of the charge cycle getting down to say under 10 amps (when the drop will be minimal) is it not likely that "it's not far out" most of the time, which in practice is about as good as it gets for most people ?

 

I will however be sticking the voltmeter across the alternator output and the battery bank posts when its at 100% (indicated) to see what voltages I am getting (suffering) and report back ( probably on Sunday ! ) just to satisfy my curiosity

 

Nick

 

 

 

Edited December 31, 2010 by Nickhlx

[bob ellison]

Tony, many thanks for your input. Topping up batteries is difficult due to boat design. This is one reason we'll go for AGM's. I'm told by one of the "specialists" that a.n.other (with this Iskra alternator/Beta 43) has gone through three battery banks which is disturbing to learn. I believe that one of the canal rescue outfits is making issue on this.

Thanks again. Your web page looks interesting. I'll digest a bit more over coming days.

Happy New Year one and all.

Bob

[Eeyore]

Tony, many thanks for your input. Topping up batteries is difficult due to boat design. This is one reason we'll go for AGM's. I'm told by one of the "specialists" that a.n.other (with this Iskra alternator/Beta 43) has gone through three battery banks which is disturbing to learn. I believe that one of the canal rescue outfits is making issue on this.

Thanks again. Your web page looks interesting. I'll digest a bit more over coming days.

Happy New Year one and all.

Bob

Hello Bob

One of the "canal rescue outfits" (RCR actualy) has been looking into this issue on behalf of a member.

 

Tony Brooks and myself are familiar with the case, but are equaly constrained by data protection issues.

 

With the consent of RCR I can supply the following:-

 

Iskra have confirmed, based on their part number as supplied to Beta, that the regulated voltage is indeed 14.8 volts

 

The case, which involved a genuine Beta supplied 175 amp alternator upgrade to an existing engine, has been resolved.

 

Part of the correspondence does refer to the existing maintenance requirement in the Beta owners manuals:-

 

"B28 to B38 and B43 to B60 page 14 section 3 maintenance schedule

Daily or every 8 hours : Check battery fluid"

 

A lower voltage regulator is I beleive available for this alternator, but I do not yet have a Beta or Iskra part number for it.

Regards

Steve

[Nickhlx]

Further to my last - ours has now done around 180 engine hours in some 15 months and the batteries have not yet needed topping. Consequently, on Sunday and assuming that the Victron has been floating it at 100%, I am expecting to find that the alternator output is around 14.4 volts (depending on temperature etc) - perhaps I was lucky and had that lower voltage regulator pack fitted from new ( engine manufactured around early 2009) ?

 

Nick

[NB Willawaw]

Interesting.

 

I'm not sure what Beta are thinking of with this latest 175A version - I wouldn't recommend this at 14.8V to any boat that I was involved with.

 

Iskra can factory set the regulation at other voltages depending on what is ordered by the OEM.

 

My advice to the OP is to contact Beta and get the lower voltage regulator - presumerably the whole alternator would need to be sent back to them for a free downgrade ?

[Nickhlx]

Interesting.

 

I'm not sure what Beta are thinking of with this latest 175A version - I wouldn't recommend this at 14.8V to any boat that I was involved with.

 

Iskra can factory set the regulation at other voltages depending on what is ordered by the OEM.

 

My advice to the OP is to contact Beta and get the lower voltage regulator - presumerably the whole alternator would need to be sent back to them for a free downgrade ?

 

 

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

I must admit I have been a touch concerned with only a 480aH bank (20 Hr rate) when new as I have seen the charging current starting off after an overnight stop of some 210 amps for a short while ( a minute or two after start up), although it rapidly drops to around 150 - 125 amps after a couple of minutes as the voltage comes up, so I guess it isn't overheating the batteries in that time.

 

However, the system has ( and still is) performed superbly and runs the high-current stuff (microwave / washer/dryer/ immersion ) without demanding any deficiency from the battery bank ( not all at the same time obviously) and I rarely see our evening / overnight drain drop the SOC below around 70% of full.

 

Next day cruising claims it restores to 100%, so I am optimistic the battery bank will last us well... At the end of a week's cruise, the shoreline maintains it via the Victron at 100% and around 13.2 to 13.6V when I check it approximately weekly... ( Note to self - I must get a new hydrometer)

 

 

Nick

[NB Willawaw]

If your 175A version is outputting at 14.4V, I wouldn't worry.

 

Theres nothing wrong with having a large alternator as such, its the constant 14.8V voltage which would bother me.

 

I'm not aware that the alternator has any temperature compensation - I think some of the auto versions have a multifunction regulator which uses a thermistor to make charging voltage adjustments

 

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

I must admit I have been a touch concerned with only a 480aH bank (20 Hr rate) when new as I have seen the charging current starting off after an overnight stop of some 210 amps for a short while ( a minute or two after start up), although it rapidly drops to around 150 - 125 amps after a couple of minutes as the voltage comes up, so I guess it isn't overheating the batteries in that time.

 

However, the system has ( and still is) performed superbly and runs the high-current stuff (microwave / washer/dryer/ immersion ) without demanding any deficiency from the battery bank ( not all at the same time obviously) and I rarely see our evening / overnight drain drop the SOC below around 70% of full.

 

Next day cruising claims it restores to 100%, so I am optimistic the battery bank will last us well... At the end of a week's cruise, the shoreline maintains it via the Victron at 100% and around 13.2 to 13.6V when I check it approximately weekly... ( Note to self - I must get a new hydrometer)

 

 

Nick

Edited December 31, 2010 by NB Willawaw

[Eeyore]

Further to my last - ours has now done around 180 engine hours in some 15 months and the batteries have not yet needed topping. Consequently, on Sunday and assuming that the Victron has been floating it at 100%, I am expecting to find that the alternator output is around 14.4 volts (depending on temperature etc) - perhaps I was lucky and had that lower voltage regulator pack fitted from new ( engine manufactured around early 2009) ?

 

Nick

Hello Nick

Can you PM me the Iskra part number off your alternator?

Would be interested to see if its the same as the one I've been involved with at work.

Not aware of there being two different versions supplied with/for Beta engines.

Have a good New Year.

Thanks

Steve