Newboy Posted December 15, 2004 Report Share Posted December 15, 2004 I need to add a dedicated cold start battery for the outboard as the 2*85a leisure batteries aren't producing the voltage needed for the CC (cold cranking ). What I really want is to connect the outboard direct to the new battery, then has a switchable connection, for charging the 2 leisure batteries in long journey, but switched to OFF most of the other time, to charge them at home. Anyone got a wiring diagram for this? Quote Link to comment Share on other sites More sharing options...
domino Posted December 15, 2004 Report Share Posted December 15, 2004 Kam, Have a look at this previous thread - http://www.pbsbac.co.uk/forum/index.php?showtopic=550&st=0 In one of my posts there is a drawing of how to connect up a two-battery system with a switch. In your case, Batt 2 (in the drawing) would have Batt 3 connected in parallel. Hope this helps, Alan Quote Link to comment Share on other sites More sharing options...
duncan Posted December 15, 2004 Report Share Posted December 15, 2004 Kam, Why wouldn't you want the alternator charging your leisure batteries too? Surely (1) you have a pretty big alternator on that O/B and (2) you are going to swap out one of the leisure batteries for the dedicated starter anyway? Whatever, I would simply use 2 battery switches, one for each battery (or bank). btw you can pick up a pretty decent CCA battery from Macro for around 38 (550 CCA from memory)- even starts mine at a pinch! Quote Link to comment Share on other sites More sharing options...
Adam F Posted December 15, 2004 Report Share Posted December 15, 2004 Kam, I agree with Duncan. 2 batteries should be more than adiquate - I think 3 will further complicate things, aslos you run the risk of more things to go wrong. The 85ah batts you have at the moment may be a bit small, even together. With my old engine I had a 85 and a 110 - the 85 struggled on its own. Id go for either 1x 85ah and 1x110 or a pair of 110 AH batts, these should provide all the power you need. Adam Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted December 15, 2004 Report Share Posted December 15, 2004 Kam You shouldn Quote Link to comment Share on other sites More sharing options...
Newboy Posted December 15, 2004 Author Report Share Posted December 15, 2004 Is the 85 alone gonna be enough for fishfinder, gps, a plotter (getting one), that's before lights and bilgh pump (in emergency). The mechanic said the 100 draws x amount of ampage (forgotten what it was) and basicly 2 x 85a leisure batteries are not enough on a cold morning, as leisure battery ain't supposed to be use as a starting battery, unless you are using a row of the 110a. I might just bolt the new 700cca (commercial transit van battery, discounted price Quote Link to comment Share on other sites More sharing options...
Newboy Posted December 15, 2004 Author Report Share Posted December 15, 2004 Kam, Have a look at this previous thread - http://www.pbsbac.co.uk/forum/index.php?showtopic=550&st=0 In one of my posts there is a drawing of how to connect up a two-battery system with a switch. In your case, Batt 2 (in the drawing) would have Batt 3 connected in parallel. Hope this helps, Alan I'm a little confused. the wiring diagram you have is slightly different to mine. On mine, the +ve and -ve from o/b connect to battery 1 direct whereas on yours, the +ve is connected to the switch. Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted December 15, 2004 Report Share Posted December 15, 2004 Kam The electronics on maverick are. 1 VHF, 1CB, 1 GPS, 1 GPS plotter, 1, sounder, plus the usual lights etc, deck wash and pumped live bait wells. Using two 85ah batteries i have not yet had a problem even with the live bait pump working all day. To date I have never drained a battery so it wouldn Quote Link to comment Share on other sites More sharing options...
duncan Posted December 15, 2004 Report Share Posted December 15, 2004 Spot on Martin - and Kam that transit battery sounds perfect as a replacement for one of the 85's. Bet you find ones poor anyway. worst case keep it as a spare. Quote Link to comment Share on other sites More sharing options...
Newboy Posted December 15, 2004 Author Report Share Posted December 15, 2004 Been looking up on batteries on YBW this afternoon. Very interesting facts. 1) You shaould never use a leisure battery as a starting battery (car). Varta and Exide say this will weaken the plate and shorten the battery life due to its high current. 2) You shouldn't use a starting battery for your onboard electronics, cos if you deplete the charge too much, it may not recover (hold another charge). 3) You should not 'fast-charge' a leisure battery as it too can weaken its plates. 4) In theory we shouldn't mix batteries of different sizes, ages or types. In practice we do and very often there is no problems. However, the stronger battery WILL take almost all the charge even tho it is full, leaving the weaker one weaker by the day. Quote Link to comment Share on other sites More sharing options...
shytalk Posted December 15, 2004 Report Share Posted December 15, 2004 oh to live in an ideal world!!!! Quote Link to comment Share on other sites More sharing options...
shytalk Posted December 15, 2004 Report Share Posted December 15, 2004 seriously though i am about to wire a boat up which has radar 10"colourplotter gps autopilot crt sounder stereo 2000w inverter 5hp bow thruster and a 420 hp engine as well and is all powered by 4 110ah batterys in series to give 24v with no problem so i would say either your batterys are past it or you have bad connections or to small capacity starter cables peter Quote Link to comment Share on other sites More sharing options...
duncan Posted December 16, 2004 Report Share Posted December 16, 2004 aren't batteries a full topic? onboard electronics shouldn't figure - unless you are drifting miles and keeping them on they will be used when the engine is on and shouldn't draw more than the alternator is delivering (radar being a possible exception to both the above statements) So the goood news is that only anchor light, cockpit light and radio will be your enemies - live bait well in the summer/autumn. Bad news is that the usable battery current is often reckoned to be 20% of the capacity on a standard alternator charged system (it will only charge to around 80% full capacity and you don't want to discharge it below 60%). With the current price of batteries I would simple use 2 cheapish 85's and change every third year. If you wire them through 2 switches, and have any electronics that give you voltage, you can quickly check if one is failing by switching to each before you start up and checking the standing voltage. 12.8/12.9 being expected. Quote Link to comment Share on other sites More sharing options...
Coddy Posted December 17, 2004 Report Share Posted December 17, 2004 Hi Thought I would add a fly to the chat, check out the current draw on a sonar/fishfinder. Due to colour and dual frequency they do take quite a drain from a battery. If you want to see what your unit draws and you have lost the handbook check out the company's web site. It has happen to me when fishing on two full consecutive days and all the electronics stayed on until we were traveling back to the slipway, I lost everything but it took a while to find out why. Good thing I have a compass mounted on the helm. Regards Coddy Quote Link to comment Share on other sites More sharing options...
Adam F Posted December 17, 2004 Report Share Posted December 17, 2004 Tis' strange Coddy - When I had my old engine - what you described above was a risk with me. Often if I left all the elctronics on for more than a few hours, I wouldnt have much kick left to start the engine - even with both batts on. Since I have had the new lump - I leave everything on ALL the time, often all day, and I never have any problems?? Quote Link to comment Share on other sites More sharing options...
Newboy Posted December 17, 2004 Author Report Share Posted December 17, 2004 That's what the mechanic said. As 2 85 ia a little light on the power side especially they are both leisure batteries which dictate that they do not and cannot produce a 'lump' of power to turn the starter over, whereas an high cca battery can and will. Or do as you did, put a bigger bat in it, i.e, 110a then it will preform better unless that too is drawn below certain level. Quote Link to comment Share on other sites More sharing options...
duncan Posted December 17, 2004 Report Share Posted December 17, 2004 Agree it's (sonar) a juice user but surely you switch it off when the engines not running ? Equally the alternator will deliver more than it draws? Re leisure batteries many still believe them to be a bit of a con and the differences between LA leisure and LA normal batteries is relatively small - and certainly no more than potentially between makes or quality in normal LA ranges. that said I wouldn't want to be regularily using a leisure battery to start a heavy draw engine. Quote Link to comment Share on other sites More sharing options...
Paul D Posted December 17, 2004 Report Share Posted December 17, 2004 Duncan, I am with you re: Leisure batteries. It is not true that a leisure battery cannot produce a "lump" of power. try shorting the terminals ( NO - don't do this ! ). Take a look at the following link and read through, makes interesting reading ( esp. Section 7 ) Leisure / Marine / Battery information 7)Watch the term leisure / deep cycle as it simply does not exist. The standard so called leisure batteries are simply starter batteries with extra support for the active lead material. This may increase the life by 5-10 %, but does not turn a starter battery into a deep cycle battery. True traction (deep cycle) are not available at a sensible price and are uneconomical to use for standard leisure use. However, if you plan to live onboard or travel the world, then do look at 6 v or 2 v traction and build your battery bank up from those batteries, but expect to pay about 3-6 times the price of so called standard leisure batteries. On a daily use cycle, the standard so called leisure battery (which is a starter battery)will last you as little as 6-8 months where as traction would last 15 years. But on a leisure rating (2 weekends per month and about 4 weeks holiday) then you would get about 5-7 years out of a standard leisure. That's if you charge it right using advanced regulators, and constant current battery chargers.) Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted December 17, 2004 Report Share Posted December 17, 2004 I'd go along with that Paul All I have ever used on my boats is marine/leisure bats and as I have aleady said have never failed to see the day through, that is until they are past there sell by date then of course they do not hold a charge and you can end up in trouble Martin Quote Link to comment Share on other sites More sharing options...
Bob F Posted December 17, 2004 Report Share Posted December 17, 2004 A "Marine" Battery is supposedly a combination of the starter and leisure battery (i.e. it has the punch to start an engine but will not be damaged if frequently run down). BF Quote Link to comment Share on other sites More sharing options...
Newboy Posted December 17, 2004 Author Report Share Posted December 17, 2004 I think the rate of deteroition also differs from brand to brand. One cannot expect a battery costing Quote Link to comment Share on other sites More sharing options...
Paul D Posted December 17, 2004 Report Share Posted December 17, 2004 Bob, According to Sterling ... " 1)There is no such thing as a marine battery. If you see a marine label on a battery it is simply words and may as well say Mickey Mouse." and for you Kam "3) Quote Link to comment Share on other sites More sharing options...
duncan Posted December 18, 2004 Report Share Posted December 18, 2004 cheap is cheerfull when (1) you have 2 batteries (ie one failing doesn't matter as long as you know it' failed), and (2) you keep the receipt carefull so that you get the 3 years is guarantees out of it. I always fail on the latter Quote Link to comment Share on other sites More sharing options...
Maverick Martin Posted December 18, 2004 Report Share Posted December 18, 2004 Kam I have just spoken to Stuart the marine electrician who advertises on our site and he is of the opinion that 2 85ah batteries are fine for a small fishing boat such as ours. If you are having problems it will probably be one of two things 1. dead battery or batteries or 2. alternator not charging your bats properly. He also suggests that you use both batteries to start the engine then run on one battery for the day (as explained earlier) so you have a fully charged unit just in case of problems. Quote Link to comment Share on other sites More sharing options...
Newboy Posted December 18, 2004 Author Report Share Posted December 18, 2004 I've checked the 2 85, and one is 12.3 and the other 12.8 after charging so I guess one of those is on the way out. , The mechanic did a check on the alternator and it's charging correctly. I usually leave them both on when I go out (mainly because I'd forgotten to switch it over to bat 2). Is it true we can't/shouldn't switch between batteries while the engine is running? Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.