Jump to content

winch split charge question


davie

Recommended Posts

being a little lazy here so copy/pasting question same as i sent in a pm to make sure i give all same info in need for help here please.

wondering if you can advise me on a winch issue please. got a new winch on my td5 90, one of bowyers goldfish tds 9500 winches.

pulling a very stuck car tonight up a steep grass hill with no drive assist and car in mud and winch seemed to pulse a bit mid to late pull. got twin battery set up already and a supposedly intelligent 90 amp split charge relay to control it.

is 90 amps enough or would pulsing be lack of power and so x eng 200 amp relay be better? winch batt and relay about 6 years old.

Link to comment
Share on other sites

So when you are mid to late pull you are likely to have more rope on the winch drum, which means you have a higher gearing and thus the motor is going to need more power than earlier on in the pull (given then drag/resistance conditions)

My guess is that as a winch motor can pull up to 500Amps, the split charge is tripping out and then resetting and then tripping out again as the demand from it is over 90Amps

For example under idea conditions a winch load of
100Amps, will all come from the 100Amp Alternator (nothing from the batteries)
200Amps, 100Amps from alternator, 50Amps from each battery
300Amps, 100Amps from alternator, 100Amps from each battery
this could cause the Split charge to trip out
so it would then becomes
100Amps from Alternator and 200Amps from the single battery, thus lowering the voltage and thus reducing the speed of the winch.

Solution remove the split charge as these are great for protecting the start battery when you are drawing power when the engine is not running, but cr*p for use with winching when the engine is running.

Link to comment
Share on other sites

great to have so many replies and pm chat with simonr

so overall it seems my split charge isnt great, but does allow for rear work lights and few other odds and sods to be run without killing main batt.

may go 2nd alternator as simon suggested, just need to find a kit for a 2003 td5 90

spoke to david bowyer as supplier of winch and he had poor opinion of split charge but had a cheap workaround,

i am almost done fitting anderson plugs to front and rear batt so suggests a cable to join two together when winching to get best performance.

just need rain to stop for a while to get it all fitted up.

very happy though that dont have to buy expensive parts as i need a new exhaust - new topic to follow!

thanks

Link to comment
Share on other sites

Its worth remembering that often a relay advertised as ,500A, will pass that current for a reasonable time without coming to harm but switching that current is a very different matter. If you hear your relay switching as described stop - let the alternator catch up with the load demand for a while. Your relay will be very grateful and reward you with a longer service life.

Link to comment
Share on other sites

Your alternator is capable of supplying 100 amps at flat out rpm. On tick over, which you usually do while winching, you'd be happy to get 20 amps. Also, getting a bigger alternator is not a particularly good solution, because this will produce even less amps at tickover. but will charge quicker afterwards.

Link to comment
Share on other sites

Your alternator is capable of supplying 100 amps at flat out rpm. On tick over, which you usually do while winching, you'd be happy to get 20 amps. Also, getting a bigger alternator is not a particularly good solution, because this will produce even less amps at tickover. but will charge quicker afterwards.

While it is true that alternator max output is at high alternator rpm, you should get more than 20amp at idle.

If you look at a typical alternator power curve

A0014833LGH_curve.jpg

They the output quickly rises with alternator rpm and then flattens out at higher alternator rpm.

If you then take in to account a crank pulley to alternator ratio (my guess of 4:1) an engine idle of 800rpm will produce a alternator rpm of 3200 rpm which is quite high up in it's output range

Link to comment
Share on other sites

So yes a link cable than manually needs connecting or a permanent one with a isolator switch is ideal when you want both winching and power protection when not running.

I also run a second alternator on my V8 and it will help with winching, but not with battery recharge.

Link to comment
Share on other sites

In my 110 I have the standard LR split charge relay fed from a 100amp alternator to both batteries, also have a internal isolator switch to connect the start & winch batts together for winching heavy loads, this can also be used as an internal jump start.

Link to comment
Share on other sites

And that /\ is a very good semi automatic system,

A bit of a generalisation but battery life is shortened if you parallel them and particularly if they are dissimilar types, so leaving them connected is a bad thing, Westerns relay takes care of separating them when needed (*1)

Connecting in parallel when charging and discharging with a very low resistance switch or bond is a good thing. The isolater switch does that.

(*1) Its semi automatic as you need to remember to remove the isolater when you don't need the extra discharge current capabilities.

Solid state switches are more reliable than electro mechanical contactors and are probably the future for high current split charging systems especially as electric vehicle technology becomes more common. Even today I use a bank of n channel Fets to control my tower winch, switches 1000A with a lower on resistance than a conventional contactor and only needs a few mA of gate current to drive it.

Link to comment
Share on other sites

And after all is said and done, Toyota stick two batteries in parallel on the 3.0D auto Hiluxs and I've never had a failure- and we run amps of discharge overnight in -20c - so its not the end of the world if you forget from time to time :-)

Link to comment
Share on other sites

While it is true that alternator max output is at high alternator rpm, you should get more than 20amp at idle.

If you look at a typical alternator power curveA0014833LGH_curve.jpg

They the output quickly rises with alternator rpm and then flattens out at higher alternator rpm.

If you then take in to account a crank pulley to alternator ratio (my guess of 4:1) an engine idle of 800rpm will produce a alternator rpm of 3200 rpm which is quite high up in it's output range

That's a very useful bit of data - its probably what I expected but had never measured and the curve is much steeper than I thought.

So what would probably work well is a little forked actuator acting on the governor cable to shift the tick over up a couple of hundred rpm when winching - I bet that would make big difference and a bit more coolant flow as well?

Link to comment
Share on other sites

I've even had a new alternator delivered with a piece of paper with it's actual measured power curve (I did think I had kept it but could not find it) and it's measured output was higher than it's rated output at high alternator rpm.

Also another trick you can do at least on Lucas EFi systems is to put 12v power via a switch to the correct pin on the ECU to tell it that the Aircon is running and the ECU increases the idle rpm by about 200rpm (like an alternator the aircon pump puts a load on the engine and the increased idle is to help the engine handle that load)

Link to comment
Share on other sites

The one everyone seems to hate is the marine split charge diode pack. Can't see why, as mine has worked as soundly as they do on boats.

The big wire from the alternator goes to the pack, and two big wires go to each battery. Current can't back-flow, so one battery cannot charge the other. I have Anderson plugs permanently fitted if I need to link them.

Yes the pack drops 0.7 volts. No, it doesn't make it low on charge. I could fit a different regulator to compensate, but I could also fit a boat regulator to change the charge curve completely? I haven't needed to yet. It just sits there and does the biz :)

Link to comment
Share on other sites

Also another trick you can do at least on Lucas EFi systems is to put 12v power via a switch to the correct pin on the ECU to tell it that the Aircon is running and the ECU increases the idle rpm by about 200rpm (like an alternator the aircon pump puts a load on the engine and the increased idle is to help the engine handle that load)

It does, but only does it for a couple of seconds. It's only intended to bridge the gap at tickover, when the aircon kicks in, to prevent stalling before the IAC can respond to the drop in RPM. It essentially just moves the IAC out a couple of steps at the moment the aircon compressor is engaged then control is handed back to the closed loop IAC control. On the plus side though you can use the input and connect it to the winch so it automatically increases the engine rpm when you start winching, allowing the engine to cope with the extra load without stalling.

Link to comment
Share on other sites

I guess I need to get a copy of rave and see if I can figure out if I could do that on my Td5...

It should be fairly easy to drop a couple of fixed resistors into the pedal sensor at the appropriate time but maybe it would make errors if you changed the overall resistance too much.

This reminds me of my Bedford MIDI van which had a cable worked dashboard control to set the idle when cold. I had a piece of wood with a slot in it to act as cruise control...youth!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy