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Post by Deleted on Nov 22, 2018 15:04:26 GMT
Oops ! No DC amps
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Post by Deleted on Nov 22, 2018 15:07:53 GMT
I'll sort it, always new I was on a big learning curve.
Now new alternator/regulator, I've no idea... (New thread or continue this one?).
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Post by Telemachus on Nov 22, 2018 15:27:46 GMT
I'll sort it, always new I was on a big learning curve.
Now new alternator/regulator, I've no idea... (New thread or continue this one?).
First, you need to determine whether there is actually a problem with the alternator, as opposed to a measurement issue or a wiring issue. Use a meter set to DCvolts (either your existing one or the new one you’re going to get!) and, with the engine running above tickover (1200 rpm or so for a modern engine) and with the batteries already fully charged, connect between the engine casing and the fat wire connected to the back of the alternator (if you’re not sure which wire, post a photo of the back of the alternator). We are talking about the domestic alternator (the larger one). Record the voltage reading. Be careful with the engine running and spinning bits, belts etc not to get something caught in the belts. So remove lose clothing, jewellery etc. In fact probably best to be naked when you do it. Oh, maybe just a jock strap in case dangly bits get caught.
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Post by Deleted on Nov 22, 2018 15:36:21 GMT
I'll sort it, always new I was on a big learning curve.
Now new alternator/regulator, I've no idea... (New thread or continue this one?).
First, you need to determine whether there is actually a problem with the alternator, as opposed to a measurement issue or a wiring issue. Use a meter set to DCvolts (either your existing one or the new one you’re going to get!) and, with the engine running above tickover (1200 rpm or so for a modern engine) and with the batteries already fully charged, connect between the engine casing and the fat wire connected to the back of the alternator (if you’re not sure which wire, post a photo of the back of the alternator). We are talking about the domestic alternator (the larger one). Record the voltage reading. Be careful with the engine running and spinning bits, belts etc not to get something caught in the belts. So remove lose clothing, jewellery etc. In fact probably best to be naked when you do it. Oh, maybe just a jock strap in case dangly bits get caught. I'll do so tomorrow and report back. Currently have no idea what an alternator looks like so have to research that first....
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Post by bargemast on Nov 22, 2018 16:25:39 GMT
First, you need to determine whether there is actually a problem with the alternator, as opposed to a measurement issue or a wiring issue. Use a meter set to DCvolts (either your existing one or the new one you’re going to get!) and, with the engine running above tickover (1200 rpm or so for a modern engine) and with the batteries already fully charged, connect between the engine casing and the fat wire connected to the back of the alternator (if you’re not sure which wire, post a photo of the back of the alternator). We are talking about the domestic alternator (the larger one). Record the voltage reading. Be careful with the engine running and spinning bits, belts etc not to get something caught in the belts. So remove lose clothing, jewellery etc. In fact probably best to be naked when you do it. Oh, maybe just a jock strap in case dangly bits get caught. I'll do so tomorrow and report back. Currently have no idea what an alternator looks like so have to research that first.... If you really don't know what an alternator looks like, have a look at this link, and maybe do the tests they show too www.google.com/search?client=avast&q=alternator
Good luck with it.
Peter.
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Post by Deleted on Nov 22, 2018 17:14:20 GMT
I really wasn't sure what an alternator looked like, think I do now so tomorrow is another day.
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Post by Telemachus on Nov 22, 2018 17:24:34 GMT
First, you need to determine whether there is actually a problem with the alternator, as opposed to a measurement issue or a wiring issue. Use a meter set to DCvolts (either your existing one or the new one you’re going to get!) and, with the engine running above tickover (1200 rpm or so for a modern engine) and with the batteries already fully charged, connect between the engine casing and the fat wire connected to the back of the alternator (if you’re not sure which wire, post a photo of the back of the alternator). We are talking about the domestic alternator (the larger one). Record the voltage reading. Be careful with the engine running and spinning bits, belts etc not to get something caught in the belts. So remove lose clothing, jewellery etc. In fact probably best to be naked when you do it. Oh, maybe just a jock strap in case dangly bits get caught. I'll do so tomorrow and report back. Currently have no idea what an alternator looks like so have to research that first.... What engine is it?
I'm guessing a modern-ish jap one because you mentioned 2 alternators. At the front of the engine will be some belts and pulleys. One pulley comes out of the engine casing at the bottom and is the crankshaft, this drives the belt(s) (there may be 1 or 2 belts). Also coming out of the engine further up will be another pulley with the belt passing around it, this is the water pump. Bolted on will be two lumps with pulleys on the front, these are the alternators, again with the belt(s) passing around them. Electrical connections will be on the opposite end from the pulleys. The slightly larger one will be the alternator for the domestic batteries (the one we are interested in) and the smaller one will be for the engine battery. Although it is possible that there is some mechanism to link both alternators together when the engine is running, but let's hope it isn't that complicated!
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Post by JohnV on Nov 22, 2018 17:44:33 GMT
I thought a 12v fridge took about 50 amps per 24hrs was hoping to get a couple of days between charges then 3 or 4 hrs engine running for a top up, then a longer run to properly charge the batteries. Yes, but you have to put a lot more into batteries than you take out. Although trickle charging for another 10 hours only puts a few extra amps back in, if you don’t do it, you lose that few percent for good. Your battery effectively gets smaller and smaller in capacity. How old are your batteries? How were they charged up by the previous owner? Depending on where you measure voltage you will see a voltage drop when you are using current from the battery (i.e the battery is under load) A good simple rule of thumb explanation. unfortunately the technology of lead acid batteries is nearly 150 years old and has major limitations. newer types using different materials are much better but unfortunately have eyewatering price tags
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Post by Deleted on Nov 22, 2018 17:44:35 GMT
I'll do so tomorrow and report back. Currently have no idea what an alternator looks like so have to research that first.... What engine is it?
Barrus Shire, thanks for the other info, I'm sure I'll be able to work it out in daylight tomorrow.
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Post by Deleted on Nov 22, 2018 17:52:35 GMT
Nick has pretty much covered it all - apart from checking voltage either side of the battery isolator switches- the ones we looked at under the engine hatch.
If your alternator is making 14.4 odd volts as it should at the B+ Terminal on the rear of the alt (fat wire connection) the volts are being lost elsewhere - common cause is iffy isolators switches and bad connections - dirty/loose etc.
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Post by Deleted on Nov 22, 2018 17:53:02 GMT
Yes, but you have to put a lot more into batteries than you take out. Although trickle charging for another 10 hours only puts a few extra amps back in, if you don’t do it, you lose that few percent for good. Your battery effectively gets smaller and smaller in capacity. How old are your batteries? How were they charged up by the previous owner? Depending on where you measure voltage you will see a voltage drop when you are using current from the battery (i.e the battery is under load) A good simple rule of thumb explanation. unfortunately the technology of lead acid batteries is nearly 150 years old and has major limitations. newer types using different materials are much better but unfortunately have eyewatering price tags Lead acid batteries have a very high recycling rate so in theory good for the planet.
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Post by Deleted on Nov 22, 2018 17:54:43 GMT
Nick has pretty much covered it all - apart from checking voltage either side of the battery isolator switches- the ones we looked at under the engine hatch. If your alternator is making 14.4 odd volts as it should at the B+ Terminal on the rear of the alt (fat wire connection) the volts are being lost elsewhere - common cause is iffy isolators switches and bad connections - dirty/loose etc. It was a good point also about the voltage display simply being inaccurate.
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Post by Deleted on Nov 22, 2018 18:40:03 GMT
Nick has pretty much covered it all - apart from checking voltage either side of the battery isolator switches- the ones we looked at under the engine hatch. If your alternator is making 14.4 odd volts as it should at the B+ Terminal on the rear of the alt (fat wire connection) the volts are being lost elsewhere - common cause is iffy isolators switches and bad connections - dirty/loose etc. It was a good point also about the voltage display simply being inaccurate. My solar controller is pretty accurate - a damn sight more accurate than the Faria volt gauge that has made way for a boost pressure gauge, the Faria instrument was little more than an educated guess!
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Post by quaysider on Nov 22, 2018 19:01:35 GMT
There's a chap a couple of boats down from us here, who insists on turning his fridge-freezer (Inlander 12v with the danfoss compressor same as ours as it happens) off over night - he claims it's well enough insulated for the food in the freezer NOT to defrost noticeably and the milk is cold enough for his cornflakes of a morning... I'm tempted to give it ago... ONCE we've eaten the expensive meat thats in there and only have a few chicken thighs/sausuages left.
We tend to go from (according to the smartgauge) from 90% at bed-time down to about 70 % by morning IF I don't set the webasto to come on for an hour ... THAT 1 hour however doesn't half clobber the batteries and they can end up another 10% down - ergo, I keep the fire going and save the batteries.
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Post by Deleted on Nov 22, 2018 19:03:32 GMT
It was a good point also about the voltage display simply being inaccurate. My solar controller is pretty accurate - a damn sight more accurate than the Faria volt gauge that has made way for a boost pressure gauge, the Faria instrument was little more than an educated guess! If the Faria volt gauge is something like a fuel gauge but monitoring battery strength then the gauge backs up the readings from the mppt - just in a rudimentary way.
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