Waterways Jim

Hey, I've been away from the forum for a while, making busy. Thanks Tony & NBW for that info, I have a better understanding of marine fridges now. Things have been going fine with the charger in place, though I never leave it on whilst I'm not there of course.

Woh - Seriously tekky stuff! I really couldn't comment. My electrical engineer friend suggested that bit about the brushes. My own knowledge of fridges is zero, but I did train as an electronics technician in my youth - City & Guilds & all that. That training was much more electronics than power and we didn't touch phase theory, as that was "power". However, I did learn about electric motors and all our work was in DC, save learning how to build a rectifier to turn AC into DC. So electric motors can definitely be DC, and as my fridge runs off DC, I assume that any motor in it must run from DC. It seems that I need to become more informed about my DC fridge!

I was careful to purchase heavy enough cable under advice from knowledgable local friends, and then only used a short length of it to test, so it wasn't a voltage drop problem. The PSU stated a 13.5v DC output, so I don't think that's it. I believe I have worked out what's going on here: The brushes in the fridge motor have worn down, so that when it starts up, it demands a high current surge which the PSUs couldn't deliver, but the batteries can. This may be wrong, but it feels right to me (after discussing with those knowledgable friends referred to above). If anyone can shed further light or vigorously disagrees with my diagnosis, please feel free... However, I can definitely live with the arrangement I now have.

I connected the battery charger and had a CARE FREE weekend at last (apart from engine probs of course) Thanx again for all advice.

I'm not with the boat/charger/etc at present so not sure John. I'm sure I've always had that with car battery chargers - maybe not. Thanx for your advice as well, Noah. Another problem is that I have three ah101 batteries, not being sure which is which. I have an isolator switch which has 1, 2, BOTH or OFF positions, but the fridge remains connected in the OFF position. This will possibly be a mystery to you guys, not being able to see the setup. The 1st one is for the engine starter (position 1 on isolator) & beyond that I don't know.

OK. I have a recently bought a charger which says it can be used to power 12v appliances as well, but I will hold fire on using it for that, due to your comments. I am almost always on the boat with my family, so charging batteries whilst there is difficult, as it is recommended that the positive terminal is disconnected (& cell tops opened), thus no battery power on the boat (main problem apart from fridge is water pump). Would you say that it's OK to charge batteries without disconnecting the positive terminal and thus have battery power on boat whilst charging batteries? Have not yet called Shoreline - life is a bit hectic PLUS my laptop has just given up.

Thanx for all your posts whilst I've been working. I did spend quite a lot on the psu, so am fairly sure that it's good. The other one I borrowed was not the same make. I do use a charger to keep batteries charged, but can only use: 1) when I'm there 2) with the batteries disconnected at the positive side, so no power to rest of boat (water pump). Will try using a charger to power the fridge. I was also very careful about the cable I used and purchased good quality cable. The quality of DC supply did occur to me, but I reckon that should be fine. I think it'd be an idea for me to fone Shoreline and ask their advice ('tis a Shoreline fridge of course). Still working, so I'm off again for a while...

The psu I borrowed had an amp metre and a voltmetre on it and the current jumped to about 10A when it was trying to start up. If the psu delivers 20amps, then that shouldn't be a problem.

Well, I thought that might be the case, but why does it work with the batteries - makes no noise (hardly) and works fine apparently.

Since I have had a problem with my engine (see this thread: http://www.canalworld.net/forums/index.php?showtopic=5645) I now have a problem with the fridge. As the engine is not helping to keep batteries charged, my fridge is running the batteries down to a point where the fridge doesn't work properly. I decided to get a 12v psu to power the fridge during this time and, as the fridge plugs into a 5amp roundpin socket, wired another 5amp roundpin socket, so that I could just move the plug across, with the other socket powered from the power supply which in turn is plugged into the hook-up circuit whilst moored up. At first I had difficulty finding a 12v psu which could also deliver up to 10amps, so made do with a 5amp one. This lasted for about a week and a half continuous use before it gave out. By this time I had sourced a 12v regulated psu delivering up to 20amps and wired that in. The fridge just woudn't have it and did not start up properly. I borrowed another 20A 12v psu just to make sure and - same thing. Now, I also have a solar panel which trickle charges the batteries during daylight hours. This means that, after a while spent away from the boat, I can actually use the boat batteries to power the fridge - for a while anyway, and the fridge starts up with no problem. My question is: WHY DOES MY FRIDGE WORK WITH THE BATTERIES, BUT NOT WITH A 20A 12V REGULATED POWER SUPPLY?? Bearing in mind that it did work with a 5amp 12v psu for a bit, i.e. until that psu gave out from too much current being required of it.

Thanx Alan, I am awaiting a quote from Peter Thompson. The boat was built in 1982, so engine probably new then. It seems the concensus is to fix/rebiuld the current engine, so I'll bow to you guys' experience and probably go that way. I have to say that my engine doesn't look quite like the pics of the Canal Star 36.

Personally, I think we should all set a good example to Joe Public and operate locks manually.

OK, here's a couple of pics of my engine... J.

All excellent advice... Ta very much.

As a new boat owner, I'm learning a lot about ropes here (cheers Howard). Boating as Life is a learning experience & one hopes that those folks who used wool (unbelievable!) for lines will never do it again. As for stuff being nicked, kids (chief protagonists) will nick anything. Where I'm moored is in the middle of nowhere, the pub next to the marina is called "The Five Miles From Anywhere No Hurry Inn" and I think it's actually more than 5 miles from anywhere, so we have practically zero security problems.

Yeah, sure. The guy who does quotes, Pete is on leave this week, so we'll have to wait a bit. I'm still up for any further advice on this matter from anyone who can & pointers to other reliable entities who may be able to help. Thanx all... J.

Wow they're good - got back to me immediately. I am instructed to find the serial number. Jim.

Thanks Neil, I have now emailed them & await a response. This is obviously not the end of it, so further posts are eagerly awaited! Jim.

Well, that is a possibility I spose. We had a survey done prior to buying which may have some clues in it, but I just looked for it & must have left it on the boat. Anyway, I'll get some pics done over the w/e. Jim.

Unfortunately, I have minimal info. When I bought the boat, I was given no details about the engine. All I can tell you is that it's a Lister Petter 4 cylinder. I had a good look last time on the boat, but came up with nothing else. Is there somewhere in particular I should look for model details. I spose I could take a pic or 2 of it when I go up this w/e for you to peruse. Thanks for your reponse, Jim.

My engine has seen better days and I reckon I need a new one - well reconditioned one I spose, as a new one looks rather expensive. What I would like is for someone to take out the old and put in the recon. An aquaintance who claims to know something of marine engines told me I could have a company do this for about £2500. When I questioned him, he said "Call your engine manufacturers". When I called Lister Petter, they couldn't help at all with 2nd hand engines. My location is Upware Marina nr Ely, Cambridgeshire. I need at least a 4-cylinder to power my 56' narrow boat. Any ideas out there. Hopeful... J.