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| donmacn Member Since: 07 Nov 2017 Location: Nth Scotland Posts: 1829  |
Morning all,
So yep, slit charging/dual batteries - again. At this stage you can probably hear the rusty tin can being opened, and glimpse all the wriggly worms inside... 
I know there's been loads and loads written about this, because I've read many, many of these threads and posts, but that's taken me to the point where I still have a couple of questions from those who understand electrics and these things better than me. In short I have these questions: 1) Is my system working properly, with the batteries I have, or have I just been unlucky and had two 'dud' batteries? 2) Can I just plug a solar panel into my existing system 3) Is there a way to efficiently/properly incorporate 240/120V hook up into things. This is what I have:  Click image to enlarge Click image to enlarge Click image to enlarge A professionally installed and high quality VSR system, with an accessories fuse box, and on the other side of the heel panel, a switch to isolate the 'house' battery. The job was done in 2018. The Optima batteries were the recommendation of the installer. There was also a 120A alternator fitted later when the rebuilt engine went in. Before anyone says "Ah, I can see your problem right there mate! Someone's nicked one of your batteries!"... I took the photos in July this year as I was replacing the Yellowtop Optima 'house' battery; I had already replaced the 'starter' battery - an Optima Red Top in March this year. So both batteries only lasted about 4 years - 2018 to 2022. My first question then - have I just been unlucky with the Optimas? I've read that they are not as good as they were. Or, are they less suited to an older Defender with a 'dumb' alternator? I've seen lots of posts to say that good lead acid batteries are fine. Happy to accept that, and if/when the next 'changeover' happens I might go that way. On the other hand I've also read that AGM batteries are better for the 'house' side of things, allowing for a lower % discharge between charging cycles. The Blue Sea relay 'locks out' when one or other of the batteries drops below 9.5V; and I think the Yellow Optima needs 13.7 volts to charge. At one stage this year, I saw the voltage (on the Madman gauge) was down to 13.9 or 13.8v. The coolbox (which is what we had then) was plugged in. I wonder if the battery wasn't receiving enough charge, slowly discharging, and eventually got to the point where it died. In short, did the VSR system kill the Optima house battery, and will it kill the new one in the same way? I've also read a lot about B2B or DC-DC chargers, about their supposed benefits, but also that they are 'uneccessary' for a Defender and limited power demands. At this stage I'm going to try and stick with my existing installation unless there's a strong case for change. If money is going to be spent, I wonder if a B2B charger is more or less expensive than changing my Optima AGM batteries to lead acid? 2nd question. I am considering adding a solar panel to things - for 'off grid' overnights; or even some campsites I've been in where the hook-ups are elsewhere/broken/too far away. I have noticed that my Blue Sea charging relay is 'dual sensing' - it will sense a charging source on either of its main connections. Can I just connect a solar panel onto this initially without going to the expense of one of the MPPT things? The relay needs 13V for 2 minutes before it opens and starts charging. 3rd question. Our main power consumer on camp stops will be a compressor fridge; maybe an LED light string and small house lights; perhaps music using the car's system if I can figure out a way to switch its power supply from 'ignition' to 'house' when required. If we were in campsites, I've nothing against plugging in to the mains. Is there an "elegant" or proper way to do this? Installing a hook-up 'receiver' socket into the car would be easy enough, but I assume it's not as simple as that, with a transformer or the like being needed to take the voltage from 120 or 240 down to 12v?? In which case do I stick with the KISS principle and just plug these things directly into a hook-up cable? Sorry, there's a lot in there I know. I could just try to find a professional to do this, and answer all these questions, but to be honest I also want to properly understand the system myself so that I can diagnose or fix it if it goes wrong while I'm away somewhere. The best way to do that is to ask my questions, and then fit things myself. Always appreciate replies to any of my questions, so thanks very much in advance, and I'm sure I'll say so again. Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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6th Oct 2022 10:54am |
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if either batt is being charged by solar or alternator the vsr will link the batts and charge both.
| donmacn Member Since: 07 Nov 2017 Location: Nth Scotland Posts: 1829 |
Thanks Mike, good to know there is no fundamental problem with the set up. How long have you had the Optimas for and are you happy they lasted OK? I guess I must have just been unlucky.
On the fridge switching - that's my bad wording - thanks for pointing it out. I had meant to say that the fridge and lights would always stay on 'house', but that the car's stereo could always be on 'engine battery' for its memory settings etc, on 'engine' for normal use while moving, but switchable to 'house' for camping nights. But I imagine its current draw would be so minimal that it probably isn't worth the hassle? As you say, keep as many non-engine loads as possible off the starter battery. I think that's largely been done - only the original cigarette lighter and stereo remained on the engine battery. And it was good this had been done, because one down side of routing everything via the house battery is that when it dies, and the VSR stops any charge getting to it, then all the wired accessories stop too, even with the engine running and providing power. I ended up without spotlights, rooflights, two of my additional cigarette lighters, my USB charger etc. I am actually considering moving the driving lights back to the engine battery - as I think they are powered direct from the alternator anyway, it's only the switches that go through the house battery. An MPPT provides more efficiency - fair enough, I think I'd read that - are there any pros/cons to putting it in via the fuse box as opposed to the VSR? I fancied the VSR because I was thinking of fitting a 'magcode' connector on the front of the seat box for the solar supply - allowing the panel to be easily removed and stored in the back of the car. This way the solar supply/charge wiring would come in right next to the VSR unit and be easy to connect. The fridge does run of 240V, and 12V obviously. I still need to check what I might need to run it off 120V if I'm abroad. Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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6th Oct 2022 7:12pm |
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| mikeh501 Member Since: 07 Jan 2013 Location: United Kingdom Posts: 1142 
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I’ve had mine a few years and I’m on my second set. The first set lasted about 7 years and only failed due to the vehicle being off road for a year tbh. Not the batts fault. The only thing about the optima is the low amp hours. For your use I’d be tempted to fit a much bigger house battery in the rear somewhere, or maybe just a third one and keep the optima house.
Iirc there’s a power wire and a always on kinda wire on most stereos. You could wire the always on to your ignition batt. The main pro for wiring the solar it to your fuse box is that it’s all nicely fused and labelled if you have issues with it. Electrically it will make no difference whatsoever. You need this kinda thing for your 240v. A batt charger would be good too. https://simplysplitcharge.co.uk/240v-mains...95531.html |
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6th Oct 2022 7:24pm |
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| macfrank Member Since: 05 Nov 2015 Location: somewhere in the north Posts: 993  
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"Can I just connect a solar panel onto this initially without going to the expense of one of the MPPT things?"
"An MPPT provides more efficiency" Just to make sure: you do need a solar charge controller of some kind. You didn't actually meant to directly connect a panel to the battery?! |
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6th Oct 2022 7:53pm |
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| donmacn Member Since: 07 Nov 2017 Location: Nth Scotland Posts: 1829 |
Brilliant Mike, thanks for that.
You’re right - the stereo will have a permanent live wire for memory settings, and (normally) an ignition powered live for running. I can’t see any reason that they can’t come from two sources. I guess it shows my lack of electrical nous, that I tend to think of the fuse box as the ‘downstream’ side of things, and not that it could be used to run power the other way. However without the engine running, wouldn’t the VSR have disconnected the batteries? Wouldn’t that mean that the supply from the solar (if wired to the fuse box) would only go to whichever battery was directly connected to the fuse box? In my case, the house battery? OTOH putting the solar supply through the VSR (if the panel was delivering 13v) would charge both batteries? Entirely possible I’ve missed something. Thanks for taking the time to post that charger link. In fact I anticipate most use being in Europe so I’d want to look at a 120v version of that, but I’m sure it would be the same sort of thing. Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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6th Oct 2022 8:00pm |
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| donmacn Member Since: 07 Nov 2017 Location: Nth Scotland Posts: 1829 |
Thank you - probably not, though I hadn’t actually got as far as looking at specific panels or controllers. I’m happy to have this specific thing pointed out though - avoids the potential for any daft mistakes! Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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6th Oct 2022 8:04pm |
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| mikeh501 Member Since: 07 Jan 2013 Location: United Kingdom Posts: 1142
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It wouldn’t make any difference if you attached the solar to the fuse box or the vsr itself. It will charge whichever side you put it on I.E ignition or house, but when the vsr detects that increase in voltage on either side due to the solar power it will connect the batteries thereby charging both anyhow. The vsr is dumb, it can’t tell the difference between the alternator or solar or just a ac batt charger. Soon as it detected the voltage going up beyond its threshold it will connect the batteries no matter if that charge is coming from house or ignition side. So really you just need to add it as tidily as you can and not worry about upstream or downstream etc. the only consideration beyond that is ensuring wherever it gets connected has appropriate gauge wiring for the load and is adequately fused to avoid a fire risk. |
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6th Oct 2022 8:28pm |
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| macfrank Member Since: 05 Nov 2015 Location: somewhere in the north Posts: 993
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"I’m happy to have this specific thing pointed out though - avoids the potential for any daft mistakes!"
Glad to hear that 
As to your other point: the VSR will connect, if it senses a charging voltage at either teminal. I have a very simple solar setup, where I connect the controller to the aux battery only when I get the panel out. It's not a permanent installation yet. Then I also disable the VSR to make sure it wont connect, because I only want to top up the aux not the starter battery. The way I do this disabling is by a switch I have installed in the ground connection to the VSR's electronic (the thin black one at the bottom, in your picture; although I have an NL system, but they are similar). This is also useful, if both batteries are significantly discharged and my CTEK isn't powerful enough to top them up both at the same time (the VSR would then go into an endless connect/disconnect cycle). |
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6th Oct 2022 8:32pm |
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| donmacn Member Since: 07 Nov 2017 Location: Nth Scotland Posts: 1829 |
Thanks both for your patience. When you point it out, I can see that it makes no odds whether the charging source is ‘directly’ connected to the VSR, or at the end of a few inches of cable and through a fuse.
I get the point too about disconnecting the VSR ground if I wanted to just charge the house battery - which actually makes perfect sense. If the starter battery doesn’t discharge through day to day use, why would it discharge when it’s being used daily on a longer trip. Thanks again. Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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6th Oct 2022 9:07pm |
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| mikeh501 Member Since: 07 Jan 2013 Location: United Kingdom Posts: 1142
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Don’t know if you have the exact same model of blue sea vsr as me,but mine has a remote operation button where I can lock it on or off or leave it auto for that very purpose.
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6th Oct 2022 9:37pm |
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| donmacn Member Since: 07 Nov 2017 Location: Nth Scotland Posts: 1829 |
hi mike,
Good point - I think they must be different. My VSR is this one: https://www.bluesea.com/products/7610/SI-A...4V_DC_120A Is this what you have? https://www.bluesea.com/products/7622/ML-A...2V_DC_500A If I understand that product properly, the yellow lever on top stops the relay working for "servicing" - whatever that might mean. Presumably stops charge current coming down a cable if there's no battery connected but the engine needs to be run. Also, the remote switch would also allow you to 'lock' the relay (and therefore isolate the batteries) so that you could charge only one of them? So in my case, with the relay switched to 'lock', I could connect the solar charge current to the accessory fuse box (which is connected to the house battery live) and any charge being supplied would only go to the house battery? Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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7th Oct 2022 9:33am |
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| mikeh501 Member Since: 07 Jan 2013 Location: United Kingdom Posts: 1142
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yes, your right i have the bottom one. The reason in my case was that I have a winch and needed much more than 120a yours is rated at.
tbh ive never used the yellow lever but i think the remote control button does the same thing. you will use the button on the VSR to effect the same. |
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7th Oct 2022 3:24pm |
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| donmacn Member Since: 07 Nov 2017 Location: Nth Scotland Posts: 1829 |
Hey Mike,
Thanks again. At something near £300 I was thinking I might just fit a switch on the earth connection as macfrank suggested, but then I found one for sale for £160, so I thought I might as well do it properly. I can always sell what I have and bring the changeover cost right down. But just to say that I appreciated you're chipping in to answer my question especially as you have the same set up and batteries - that counts for a lot. Cheers. Now to go and investigate the solar side of things.
If I can find a magcode connector that would be properly rated for the solar charger, then I'd try and put that and the relay lock switch in the same location - minimising any risk of forgetting to unlock the relay when disconnecting the solar. Donald 1994 Defender 300Tdi 110 SW - owned since 2002 - 230k miles and going strong (The 'rolling restoration' or tinkering thread: http://www.defender2.net/forum/topic58538.html ) 2000 Range Rover P38 4.0L V8 in the past.. RR classic - fitted with 200Tdi 1984 RR classic - V8 with ZF auto box 1993 Discovery 300Tdi not to mention the minis and the Type 2 VW camper... |
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7th Oct 2022 7:29pm |
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