GARDRB Posted February 27, 2022 Share Posted February 27, 2022 35 minutes ago, cletus said: Electrical question. if I'm using fused relays, do I need to run circuits through a fuse box first? Would prefer this for simplicity. Or is it better to use regular relays and a separate fuse box? Will use relays for fuel pump/fans/ignition box /etc In my opinion... If you're running fused relays and the wire from your positive feed is capable of handling the current and any over current conditions and isn't at risk of rubbing through the insulation to the conductors, then go for it. It it's a nice short run from power source to relay you should be fine. I like to fuse as close to the battery as possible though. 1 Quote Link to comment Share on other sites More sharing options...
cletus Posted February 27, 2022 Share Posted February 27, 2022 My plan is to have the battery in the boot, cable runs up to a plate mounted under the dash with all the relays , coil, and ignition box mounted to it, with a insulated terminal that I can bolt the main cable, starter feed, and alternator wire to. I have heard that the alternator wire should go directly back to the battery , but not sure if that's an old wives tale or a real thing? Can probably fit one of those big 200amp? circuit breaker /fuse things at the battery in the boot if thats safer as well Quote Link to comment Share on other sites More sharing options...
datlow Posted February 27, 2022 Share Posted February 27, 2022 Yeah definitely a big fuse off the battery 1 Quote Link to comment Share on other sites More sharing options...
yoeddynz Posted February 28, 2022 Share Posted February 28, 2022 My only issue with having everything off the battery fused means that in an, albeit rare, occasion where you might just need to move the car in an emergency using the starter alone it could then trip that circuit breaker. Thinking situations like when you get stuck in a ford/on railway line etc ( yeah I know, rare as) But I guess you can't do that trick with an auto equipped car anyway? 1 Quote Link to comment Share on other sites More sharing options...
igor Posted February 28, 2022 Share Posted February 28, 2022 You could always wind it out on the starting handle @yoeddynz. 1 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted February 28, 2022 Share Posted February 28, 2022 Is the starter motor ever fused on any vehicle? I thought they are always pretty much just a big honking cable capable of delivering many hundreds of amps at a direct short. Should always run the alternator sense wire directly to battery by itself, you can put a small fuse (like 1 amp) for this wire. There will be effectively zero current through this wire and it is essential there is no load on this wire or your output voltages will be wrong. The output of the alternator can just feed into the general 12 Volt network wherever you want, but you will still want a fuse on that. 1 1 Quote Link to comment Share on other sites More sharing options...
bigfoot Posted February 28, 2022 Share Posted February 28, 2022 17 minutes ago, ajg193 said: Is the starter motor ever fused on any vehicle? I thought they are always pretty much just a big honking cable capable of delivering many hundreds of amps at a direct short. Most vehicles that have factory battery in the boot seem to have some sort of fuse, battery in engine bay is such a short run its not worth it 3 Quote Link to comment Share on other sites More sharing options...
Mof Posted February 28, 2022 Share Posted February 28, 2022 Run big cable directly to starter, then smaller cable to fuse box/alt etc 3 1 Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted February 28, 2022 Share Posted February 28, 2022 I'm literally in the throes of doing this right now. Auto sparky mate said those fusable link wires aren't a thing anymore. Gave me a nice 80A plastic fuse. I'm also running an isolator switch between the battery, and the starter. Ain't nothing worse than when the smoke escapes from the wires, and you cant easily unhook the battery. 2 Quote Link to comment Share on other sites More sharing options...
h4nd Posted March 13, 2022 Share Posted March 13, 2022 Speaking of battery stuff. I have a battery (was 10.8V) I'm trying to save (just for interest). My 2.2A charger wasn't doing the biz, and @RUNAMUCKhas been kind enough to loan me his 3 or 4A "Pulse charger" (MSPaint graphs coming later). It's slowly clawing the peak voltage up, which looks promising. My Q is: what happens if I invert the battery and slosh it around to try and loosen the crystals / acid-salts/whatever while it's charging. Does it short through the electrolyte and explode, or go flat real fast or some nonsense? ( @ajg193, Autosparkies?) Anyone with experience with flooded lead acid batteries from roll-overs etc? Thanks team. Quote Link to comment Share on other sites More sharing options...
Nominal Posted March 13, 2022 Share Posted March 13, 2022 You can drop it onto the floor from a few inches to help loosen stuff up. 2 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted March 13, 2022 Share Posted March 13, 2022 You can borrow my 5A ctek charger and use it on rejuvenate mode. It hasn't failed to save a battery yet 1 1 Quote Link to comment Share on other sites More sharing options...
tortron Posted March 13, 2022 Share Posted March 13, 2022 3 minutes ago, ajg193 said: You can borrow my 5A ctek charger and use it on rejuvenate mode. It hasn't failed to save a battery yet I haven't had much luck with agm motorcycle batteries with mine. They are probably worse case scenario tho. Maybe 2/10 come back 1 Quote Link to comment Share on other sites More sharing options...
ajg193 Posted March 13, 2022 Share Posted March 13, 2022 Takes some special abuse to kill AGM battery in the first place though Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted March 14, 2022 Share Posted March 14, 2022 I saw a video on you tube (uncle Tony's garage) where he blasted a fucked battery with a big shot of juice from a welder. Came up mint. 2 Quote Link to comment Share on other sites More sharing options...
tortron Posted March 14, 2022 Share Posted March 14, 2022 Safety squints Batteries are pretty hardy, built for vibrations, so smacking them around a bit doesn't hurt them. I have one I have rolled down a hill and left sitting on its side till I went and got it. no acid even came out Watch those guys in Pakistan refurbish the plates, there's hardly anything to go wrong Quote Link to comment Share on other sites More sharing options...
Sunbeam Posted March 14, 2022 Share Posted March 14, 2022 On 14/03/2022 at 11:39, ajg193 said: You can borrow my 5A ctek charger and use it on rejuvenate mode. It hasn't failed to save a battery yet Mine has failed to save the Aqua battery (AGM) but it is 9 years old, so meh. Worked mint for a week but now it’s running low again. 1 Quote Link to comment Share on other sites More sharing options...
RUNAMUCK Posted March 15, 2022 Share Posted March 15, 2022 I'm actually keen to try the blast it with a welder trick. Totally not keen to get splattered with scalding hot acid though. [Sharn] My brother was once involved in a laboratory explosion, and was very very lucky to only get a few minor burns on his leg. Emergency services were amazed he wasnt killed. Quote Link to comment Share on other sites More sharing options...
Carsnz123 Posted March 15, 2022 Share Posted March 15, 2022 On 14/03/2022 at 20:47, RUNAMUCK said: I saw a video on you tube (uncle Tony's garage) where he blasted a fucked battery with a big shot of juice from a welder. Came up mint. Have watched similar videos of starting bulldozers in the Canadian winter. Build fire under engine to pre heat it and hit battery with welder for extra cranking juice 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted March 15, 2022 Share Posted March 15, 2022 17 hours ago, RUNAMUCK said: I'm actually keen to try the blast it with a welder trick. Totally not keen to get splattered with scalding hot acid though. [Sharn] My brother was once involved in a laboratory explosion, and was very very lucky to only get a few minor burns on his leg. Emergency services were amazed he wasnt killed. Well, your charger is no longer making progress on it. I'll gratefully try one from @ajg193, and if no joy we can try that when I come to borrow your mig for a minute (please). 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.