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My domestic alternator has stopped charging and the duff alternator has no ID, see pics. I'm at a bit of a loss to how I find a direct replacement. Are 'car' alternators interchangeable? I'm hoping to have a self-sensing replacement.

I have had the Wakespeed WS500 module for some time but have not got around to fitting it for a couple of reasons. The first is that last year there were reports of hunting / cycling as Wakespeed had adjusted the PID parameters in the control which I know led Ed Shiers of 4 counties Marine to lean more towards the MasterVolt Alpha Pro. I was not going to go Alpha Pro as the boat is all Victron including the Cerbo GX monitoring system. Secondly, the boat was launched mid 2021 so I was waiting for a few years to pass just in case something went wrong with the boat before I started tinkering and giving an excuse for not honouring warranty. I may have considered a Zeus now or the WS500 Pro with Bluetooth, but I had the older Wakespeed kit so I have stayed with it. I have a standard Beta 43 with the Iskra 175A alternator driven by a 3:1 belt which means at tickover the alternator can deliver more than 150A cold. My battery bank is a set of 6 x 115Ah AGM batteries giving 690Ah and these can take in a lot of charge. This meant that first thing in the morning the engine would struggle on tickover when put into gear. Even later in the day if a high power ac device was started whilst at low revs the engine rpm would get bogged down. The thing that has pushed me to get around to doing it is a few instances where the AGMs had started to get overcharged this year as the alternator has no float. One issue with AGMs is if they get full then they start to warm up, which reduces the resistance, which increases the tail current, which increases the rate of heating and thermal runaway can occur. This has typically occurred where we have done long days in the summer. I bought a basic Mahle regulator/ brush holder from ebay, cut off the regulator and soldered wires onto the brush contacts using high temperature cable with added protection of fibreglass sleeving. Changing the existing regulator for the hacked dumb brush holder was straightforward. I added an alternator current shunt (a basic Victron 500A/50mV bare shunt). Due to the way the boat is wired I could fit this into the negative circuit avoiding the need for fused sense wires. The install was straightforward apart from the CAN cable from the WS500 to the Cerbo GX. The devices use different pin layouts and a few years ago the UK importer did not stock a premade cross over cable. My own cable needing remaking during the install. The supplier now sells properly made cables. On the back of the engine panel, I disconnected the wire from D+ and replaced with the lamp wire from the WS500. I also cut into the domestic alternator +12V supply that is live when ignition is on (purple cable on mine). I have the controller set up and tested to give 40% field current at tickover which gives 50A charge current, rising to 100% field at 1200rpm. I may be able to have it ramp up faster but will see during use. I have the feature in wire connected to a relay on the Cerbo GX (could have been a switch I suppose) to force the alternator to float. In the summer on days with lots of sunshine, I can leave the alternator on float when travelling and let the solar charge the batteries. I have also got the WS500 set to slower response based on comments about previous problems. The only downside to this is if the rpm is increased to 1200rpm, then the WS500 slowly increases the field to the new value so the alternator loads lags behind the rpm due to the pull back function. After a few seconds the rpm starts to sag as the alternator comes up to full load, but once there it does not hunt. As more experience is gained then I will try the faster ramp. I have not yet had it on charge for long enough to see how the temperature regulation kicks in. The info sent to the Cerbo GX means that I get everything needed so not having the BlueTooth functionality is not an issue for monitoring as I can see everything on there. I still need to take the lid off to do programming to connect the USB lead but once set up that is not a major issue. The plan is to make sure it all works and see how the AGMs are working next year, they are showing some signs of ageing but still working well. Then next year see about a lithium install.

Hello - apologies if I am asking for an answer 100s provided! I have currently a flat (and trashed!!) starter battery. Its done, finished, we shall not see her again.... I am wondering why it has failed though, and thinking of my alternator. Before I buy a new starter battery, does anyone have any troubleshooting steps I can take to see if my alternator has packed it in as well (and is the reason to the failure!). AS a sidenote, I am currently relying on a jump from my leisure rig to start my engine as I am in the middle of a cruise back to my home river(s)... Could anyone advise on how long this is an option for until I risk damaging my leisure batteries? Thanks so much

Three weeks ago I had my engine serviced, alternator replaced and the belt too. It snapped yesterday whilst I was charging our batteries. Is it possible that the new alternator isn't correctly aligned? Or the belt was to tight or just duff? Or is the alternator to big for the belt. Running on a BMC 1.8. One 10mm belt for water pump and 90amp alternator. They said they would usually only fit a 70amp alternator to that size belt (to which I said "that's fine") but they ended up sticking a 90 on it (Which is what was on there before and I was going through a belt once a year or so...) I have a recently installed a Stirling alternator charge controller, I think that this increases the load on the alternator, so that might be why it's too much? There isn't any room increase in belt thickness or add an additional belt as the engine is right next to a bulkhead, so the whole lot would need moving backwards... Presumably possible but pricey? Any ideas? Should I just buy a smaller alternator and get someone to fit it?

We have a Beta 43 engine with twin alternators. The domestic 150A alternator charges four domestic AGM batteries which are now just over 2 years old. The boat and the alternator are nearly 9 years old. Normally the domestic alternator charges at a voltage ranging from 13.8 to 14.5 volts. On a recent trip it was charging at 14.8 to 15.2 volts. The batteries were not hot after several hours at this charging rate. I have no way of measuring the current at which it was charging. Should I be worried about this and what might be the reason? We have no separate regulator between the alternator and the batteries. We do have a solar panel (100W) charging the same four batteries through a regulator. The solar installation is also about 2 years old. Any ideas?

Hey everyone, new to boating and still very dumb about it but trying to learn. The problem relates to the batteries, I have a solar panel and charger and the charger tells me the voltage of the batteries. When I charge them via the engine, the voltage can go up to 13 - 13.2 volts which says to me they are charged but it only takes an hour or two. I've been told I'm not charging them for long enough but if I leave it on charge for longer it generally stays the same voltage the whole time and when I turn the engine off, it goes to 12.9-12.7 which I'm aware is fully charged. An example today is my voltage was at 12.2 so I charged the batteries for 2 hours, the batteries were at 12.7 when I finished charging and they're back down to 12.2 again after only 2-3 hours even though I've only had LED lights running and 1 usb charger for a mobile. What I'm basically asking, which has been mentioned on my previous posts, are my batteries knackered or do I need to leave them charging for longer regardless of what my controller says? I've ordered a generator and battery gauge so hopefully that will give me more answers. Thanks! Oh also, I have 2 x 110amp leisure batteries.

Hi there, I've got one of these (see pic below), but want to change it for something that can take more solar panels and is a bit more modern. We use it with a 60A alternator, and 1x 100w solar panel (although I think this regulator can only take up to 60w solar. We don't have a wind turbine. It only seems to produce a max of 14.1v when the engine's on (even after hours of cruising) and recently has been hitting 15.1v through the solar panel - which seems a bit high?! I'd like to replace it with a charger suitable for the alternator, and maybe solar as well. Do I need to get a separate charger for the alternator, then an MPPT charger for the solar panel (I also want to add either one or two 175w solar panel to make 275w or 375w in total). We have 3x 110ah leisure batteries and a starter battery, and a Sterling 1600W pure sine wave inverter that is yet to be hooked up.. Any advice, brands, models to watch out for etc, most welcome! Cheers, Alistair

Hideehi wondrous canal-skaters! Our engine room is a mess! The floor above the engine is held up by bits of wood, nailed into other bits of wood, which are glued to the paint on the hull..... several rust patches attest to the silliness of this plan! The glued bits of wood seem to be for guiding things like fuel lines ... not for load-bearing! Eventually, I want to build a new platform above the engine, with a steel frame. It should be much quieter, boxed in. Even so, when walking between the engine room and the boat, we have to step over this great big alternator, which is often moving! One should not wear flowing cotton dresses when crossing this point, which is a shame. We have two alts, one at 110Amps for the 450AH leisure (above) and a smaller one (90ish Amps) for cranking. The engine is an Isuzu 42. My plan of the moment, is to either move the larger alternator to the opposite side of the engine, or to just swap it with the smaller one. If I move it, it'd have to be mounted not on the engine, but on a piece of steel I'd have fabricated, mounted on the same girder that the engine is mounted on. If I swap it, the now lone alternator would have to charge both batteries. I don't think that this would be a problem..... both are charged by a fairly large solar panel; we stopped for two weeks without running the engine, and had no problems. That said, split relay charging systems have their own issues. The 110A alternator is on the left here. I think it could be mounted on the girder on the right, if I invert it 180 degrees, keeping the wheels lined up. Not sure if the direction of travel matters, or if it can't be mounted on the not-engine. (I figure that the fanbelt with absorb any movement?) Any ideas/input/abuse enthusiastically received!) PS, it's nearly 3am, and I'm sat in the fields, in a canal drinking good scotch, using my laptop with wireless broadband, powered by solar energy*! Life is good. . *and a little bit of diesel

Melaleuca has an electronic tachometer, driven from the W terminal on the alternator. The tacho is made by VDO and the alternator is a bog-standard A127. The tacho has started to misbehave when the batteries are charged and the charge-current reduces to a low level. The reading becomes erratic and then falls to zero. I can see why, in theory, this might happen, but it never used to. The alternator was stripped, cleaned and checked over the winter, and this behaviour is since that was done, but that may be coincidence. There's an ammeter on the alternator output, so I can be sure it's working as usual. There's an Adverc controller attached; taking that out of circuit doesn't help. Any suggestions for things to check/fix or ways to overcome the problem. MP.

We have a Victron Phoenix Multiplus 12v/3000 inverter charger, connected to 5 AGM batteries (675ah) monitored by the BMV 602. For the last five years it has worked very well. Normally whilst cruising the domestic bank of batteries is charged up by the large DC alternator (we have a smaller DC alternator for the starter batteries and an AC alternator with a Dometic travelpower). We normaly lose about 18% charge overnight and the DC alternator begins putting in about 80 ah's dropping to about 16 after 4 or 5 hours cruising. It drops lower slowly and if it remains constant for about 15 mins it is considered full (although i know this is not strictly true). I occasionally sync the BMV, once I now the batteries are as charged as they can be, usually when on shorepower and no real load. Occasionaly whilst running AC appliances (washing machine, or carpet sweeper) the Amp/hour rate goes up by 10 to 15 % the multiplus taking the extra energy from the AC alternator. This becomes negligble fairly quickly. Our problem now appears to be that the BMV does not read the output from the alternator. In winter we normally fully charge the batteries and leave some greenhouse heaters in the boat connected to the shorepower. The battery bank has very little load so we visit once a month to run the engine and charge up the batteries amongst other maintenance tasks. On our recent visit the BMV state of charge showed 74% initially but as soon as I started the engine the display changed to 100% in seconds. The rate of charge/discharge showed +3 ah dropping quickly to +1ah not the +80 plus ah as expected and normal. I considered that the alternator wasnt working but it appeared to be doing so, I started up the travelpower and put a load on the AC system and that should have had an impact on the BMV but didnt. I dont think either alternator has failed so my thoughts are that the BMV must have reset itself or shorted out somehow. It later showed a minus value as some of the lights were on in the boat. All indicators show that the BMV is not reading any input. The values held in the memory of the BMV show the same as previously I.E. the total AMP Hours of the battery bank. It seems like the BMV is not reading the input from the alternators. A blown fuse or similar is what we are hoping is the solution but where to look is our problem before we call in a Victron trained engineer This year the boat has seemed colder but we have used the same regime in other marinas. Any thoughts gratefully accepted regards Malcolm & Anne

Hi there Having an issue with our alternator and was wondering if someone knowledgeable could help. Starting up our BMC, it usually takes a small rev to kick in the alternator and send power to our batteries. Lately - no matter how much rev I give, the alternator is simply not kicking in. I've checked the cables, they are all fine; there is plenty of tension in the belt and it appears fine running; I've checked the batteries and the connections from there too. My neighbour is having exactly the same problem unusually. Any ideas? Thanks.

I have a Beta 38 with twin alternators (65 and 45 Amp), a 330AH domestic set and a separate starter battery. Everyone (Calder included) seems to advise some kind of alternator regulator to reduce charging time/increase battery life etc. Should I: just get a regulator for the 65 Amp connected to the domestics, and leave the starter alterator/starter battery out of the equation completely? get a more sophisticated regulator/splitter/management unit (e.g. the Sterling Alternator-to-Battery Charger) which would allow me to run both alternators in and then have the unit split the charge etc? I'm not keen to just increase the 65 Amp alternator BTW which some have advised, as it would involve putting extra brackets etc on the engine. Any thoughts - integrated system or keep it simple? That said, the ease of wiring in the more pricey unit has its appeal ... Patrick

Hello, I've been having a bit of trouble with charging recently. My batteries are quite low, and the alternator doesn't seem to be charging them enough. The alternator kicks out 13v max (even when charging for a few hours). I don't have a generator or battery charger to whizz them up to full so relying on the alternator. I've ordered a clamp-on ammeter to see what sort of power the alternator is kicking out (and see if something is shorting and draining power), and have inquired with a tacho seller to check if his tacho will work with my alternator, to check the RPM. I was wondering if someone could clear up the connections on the back of my alternator. The connections are on page 33... http://www.prestolite.com/literature/alts/PP1184_Buyer_Guide_alt.pdf I currently have 2 spade connectors coming from the two ++ "European Output Connections", and one from the excitation terminal. What are the AUX and B+ connectors for? Also, I don't have a connector for the battery temperature sensing terminal - should I have one? PS. Does anyone know if this tacho should just simply work by connecting to the W connector? Still waiting on a reply from the seller... http://www.ebay.co.uk/itm/Tachometer-Rev-Counter-0-6000-RPM-Alternator-Driven-Type-With-W-Terminal-/371043881967?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item5663f053ef Thanks a lot, mibix

Hi there, We have recently been having problems with losing power on our batteries, so around 4 weeks ago, we have 4 new leisure batteries fitted. However the problem has continued. Our inverter has started beeping and the fridge is cutting off, so i think the batteries have lost power. -We had the batteries fitted by experts, so I think they were fitted properly. -We charge the batteries from the engine. And have been running the engine for at least an hour a day and sometimes up to 4 hours to attempt to recharge. -We have only been running lights, fridge, tv (sporadically) and water. No charging/laptops etc. -We only turn the inverter on when we need power from the sockets, which is around an hour a day. -We have been reassured that they were top quality batteries If anybody can help with advice as to why we are losing charge/not charging up, any advice would be appreciated, as we have no power at the moment. I am also worried that the £450 we spent on new batteries has gone to waste and that the batteries are now dead. Thanks

Could anyone recommend a replacement 70 Amp / 12W alternator? My existing alternator has a HMI part number of 900021-ALS and charges the starter battery. When I google the alternator the following website has the existing alternator listed: http://www.prestolite.com/pgs_products/specs.php?item_detail_id=13070&item=66021126&product=ALTERNATOR Is it still available? Can you replace just the regulator / brushes? I intend to remove the faulty alternator this weekend so any advice gratefully received.

Hello, and it is customery to apologise for ones daftness in these situations, so uhh, sorry about that! But as the darkness and coldness approaches...I could do with some advice Here is the rub 1. Batteries no longer receive charge when engine runs. 2. Batteries do not hold charge adequately.(drops to 10v at night) About my set up. I have 3 80 watt solar panels and mppt controller I have 40 amp alternator I have sterling 4 step alternator regulator I have 2 little black boxes one of them has relay written on it The battery light no longer dims when engine runs Need to fix, spending as little money as pos. What do ya reckon? Cheers Martin

Was chatting to wife when I heard a distinct ripple in the sound of the engine. Not so much an up and a down, a bit like we had the washing machine on and the engine altering the load only, nothing was on. Then a return to a quiet too quiet smooth engine sound and upon inspection I noticed the red light was on and the battery monitor was reading negative amps. We had of course decided we weren't moving on .... how times change. Late in the afternoon we moored up at Braunston ready to hit the locks tomorrow. I might add, like all good scenarios, the batteries were sort of charged to 90% give or take a bit of innaccurate resetting Anyway, point is, we had sufficient power for tonight. Spoke with Adrian at Beta Marine and a new 100amp alternator for £135+vat seems not too unreasonable but first we will have to get ot our winter mooring, Yelvertoft, ASAP so we can get an electrical hook up. What really is truly amazing, we have a Honda 2kW suitcase generator but sadly no petrol! Enquired at Braunston to see if any petrol going and quite indifferently informed that the local petrol station at Daventry, was 5 miles away. Fair enough, won't bother to ask how much for an overnight stay, and no I don't want a hook-up ty v much .... I have checked out all the connections, so I don't expect any real surprises when I start up the engine tomorrow but who knows ... Christmas might come 2 days early .... we shall see :)

Excuse the idiot question, but: My boat has a single alternator running of a Lister SR2 There is an indication light on the control panel that indicates when the alt is charging. When lit green its not charging, increase the revs, it goes out. I've had the boat six months, when I first got it, it would only charge at high revs and then I'd ease the revs and it would still charge, but stop charging at idle. AT cruising speed my ancient ampmeter would show about 10 amps. Then it stopped charging at any rev speed. I tightened the belt, it started charging again as it was. I thought the belt tension was a bit much, ie only perhaps 5 mm on the longest length. It's now stopped charging at any rev speed, the belt is already as tight as it can get, the belt is not slipping and the alternator is turning with no noise. What I haven't done: Taken a volt reading off the alternator itself. Found out what the alternator type is. Does this sound like the alternator is knackered? Is it worth taking it to a car electrical place or simply get a replacement? Incidentally I have very low electrical requirements, ie no fridge, TV, etc. and an 8o w solar panel that keeps the batteries at about 12.9v (so far) Thanks in advance for any help AF

Hi everyone, As discussed in http://www.canalworld.net/forums/index.php?s=5dc518cf8a09055355d099b8c954c3c2&showtopic=62621 I bought a replacement alternator and fitted it. Its exactly the same and fitted with a new belt. My problem now is the engine won't start! Initially when I turned the key nothing happened at all but after checking all the wiring is seated properly the engine tried to start. I did the usual heat for 30 seconds and then turned the key. The belt just spins and there is no sound of the engine attempting to start properly. I have checked and the diesel line is open, the battery is hooked up and the charger has been on so it is charged. The only thing I think is different is that the spring in the hole at the top right of here.. ..doesn't glow red when I turn the key to "heat". I am pretty sure it did before (although I may be mistaken). Could this be it or is there something else I should be looking for? I am still learning about engines and electrics so sorry if this is a stupid question

Hi there new to the community so I hope it's alright to create a new thread. The narrowboat I'm currently looking to purchase is set up with an alternator, 3 new 12v batteries, no inverter, mains cabling throughout. There is also a generator on board. I'm sorry I can't provide specifics at this point, but even general advice much appreciated. If I continue with the purchase, I'm intending on putting on 4 Renogy 100 Watts 12v Monocrystalline Solar panels and doing my best to use the engine for power as minimally as possible (going into winter I realise that the solar is not going to give much power). The current owner will also be putting on a new 12v Fridge if I go ahead with the purchase. The appliances I intend on running would be a toaster, iron, TV, record player, iMac (I already own this and not looking to replace it), Laptop charger, Mobile charger. I'll be replacing all the current lighting with LED. There is currently a Washing Machine on board but the owner says its best to remove it as its on the mains (makes sense, although I would consider keeping it if anyone could provide a realistic solution). Stove and oven will be gas, have yet to decide on a water heating system. The current gas boiler is defunct. Currently considering a new gas boiler or a back boiler for the burner (no burner currently on board looking to purchase) to fuel hot water (taps, shower) and heating (there are radiators throughout but I'm not sure if they would be necessary once I purchase the burner - she's 63'. To be clear I will not be mooring up and 'plugging in', so everything needs to be off grid power. My knowledge is limited so being completely open, I apologise if my questions appear naive any support appreciated: Is it better to consider investing in a good inverter, or should I look at transformers on an appliance by appliance basis? If primary usage was 12v, would installing an inverter affect functionality or can you run both 230v and 12v with an inverter? I'm not particularly keen to keep the generator but would anyone advise that I do and why? Instead of an inverter or transformers would anyone's opinion be that I simply run the engine (with alternator) when using non-12v appliances, and why? I want to reduce emissions and costs from over using the engine unnecessarily wherever possible. Will the current 'all mains' wiring cause any problems with purchasing 12v appliances e.g. the fridge. If I wanted to consider keeping the washing machine what would you recommend having in place? Thank you for your advice.

Hi, I won't go into all the history of why I need this but I have a damaged Adverc (Negative) and an alternator which I am pretty sure is wired for the opposite type. I have no details on the alternator make it is a refurbished grey painted unit with no markings apart from the terminals. There is a picture of the alternator attached. I don't want to get the Adverc fixed until I have the alternator sorted. They have offered me a new alternator but it does not have the correct multi ridge pully that my engine has so it would need more alteration etc. Does anyone know if it is easy to a) Check that the alternator has the incorrect set up i.e. regulator on non earth side of field brush. b) Re wire the alternator so that it will work with the other polarity Adverc. I'm guessing the answer is no but worth checking. In which case where could I pick up a good 12V 110 Ah ish alternator which is suitable for a Negative Adverc. Engine is a Beta 38.

I'm not an electrician so need help. Isuzu 35 engine with standard wiring and engine control panel. Problem:- Control panel warning buzzer is sounding, not continuous but with frequency increasing with engine revs, and engine alternator warning light is similarly showing. On board electrical panel indicates engine alternator is pushing +14.4V and charging amperage is satisfactory (as is auxiliary alternator), both engine and auxiliary batteries charge fully no problem. Both alternators bench checked OK so, looking at the Isuzu wiring diagrams I see 3 diodes at warning buzzer and thought I'd check them. NO JOY! Can't find diodes in panel wiring at all but do find 2 resisters (CGS SBCHE4 47R J PW LA) which according to the diagrams ought not be there. Shall be grateful if someone will tell me what's going on as the sound from the warning buzzer is driving me crackers and I don't really want to disconnect it as it serves as warning for oil pressure and water temperature as well as engine and auxiliary electrics.

we have 2x 230ahc 12v Haze gel maintence free batteries, and a NASA BM-1 battery/charging monitor (which i love!). Before i start the engine, the BM1 reads: 13.5V Charging 2.4a (from Solar - inverter off, no 12v load) 88%C Time to Charge 25hr. 731 Int Ahr. I start the engine and.... Between 15.2 and 15.4V Charging between 1.2 and 4.2a Time to Charge between 9.3hr and 77hr. 732 Int Ahr Is this voltage too high?? ALSO the D Battery warning light is flashing about once per second with an accompanying chirrup and a "hunting" of the engine revs - this at about 1200 rpm. Nothing above changes at 1400 rpm and a good engine rev makes no odds. At tickover the warning light is solidly on. The engine is a Beta38 with a 100A alternator.. The Label says : LSKRA 14V 100A. (AAK5535) We both have a week off next week so i'm thinking of getting someone to look at it, BUT.. Am i likely to "fry" the batts at 15.4v if i take a few hours to chug from the bottom-ish of the Ashby to (say) Springwood Haven? (EEK! ) Any one else know any marine sparks up this way ? Currently @ Trinity Marina but supposed to be moving to our new mooring between bridges 4-5 on the Ashby on Saturday (soooooooo happy about this!! )

I'm sure everyone remembers my poor charging regime and the lengthy thread that ensued. I'm still using my set of somewhat reduced capacity 4x110ah batteries - a couple hours engine running in the morning, a couple in the evening, and then switch off the 240v (including fridge) at night. This gives me enough laptop time in the evening, led lights and various pumps etc. So, for now carrying on quite happily - but I have noticed a new phenomenon creeping in lately. Today for example: I ran the engine for an hour or so when I got up (with 240v back on as normal). I then cruised for 3 1/2 hrs. A couple hours later, and my batteries are already back down to 12.3v so I have fired up the engine again. What I am saying is this - it would appear that the leisure batteries are not getting much (or any?) charge when I'm cruising. I can't think what this could be but I'm sure someone will enlighten me - be gentle! Just to re iterate - I know the batteries have reduced capacity, but a couple hours charging off the engine normally sees them up to say 12.8v which lasts all day or all evening. Even on longer cruises, they don't seem to get as much charge as when the engine is just running in neutral. I have two alternators, 50a for engine, 175 for leisure.

The regulator on my alternator is set to 13.8V. When I end a cruise and go on shore power it takes hours before the battery is fully charged. Would it be a good idea to use the 14.5V setting or would this cause damage to the batteries when cruising for eight hours a day? Would a battery controller be worth fitting? Is Adverc still the best choice?