123hotchef
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they are not all connected over night my one will not be
- Thread starter 123hotchef
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they are not all connected over night my one will not be
Quite. I thought this was the point of the split charge!
normspanners
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No they are not, a smart charge one maybe eventually you need to listen to people that have experience of this problem first hand it is common knowedge that batteries are not fully charged by the average car system, an alternator is fitted to maintain the electrical requirements of the car not the battery and most batteries should be fully charged before an alternator is connected in fact, otherwise alternator or battery damage WILL occur. albeit slight but the rot is set usually in the less dominant battery. .1-.3 of avolt can make a massive difference to whether a battery is dominant and controls the alternator regulator.
normspanners
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that is on a standard twin battery connected battery setup that J1nx was talking about
normspanners
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What are they & why might I need to use one?
Battery-To-Battery chargers allow you to charge an auxiliary / leisure battery from your alternator whilst driving. They are installed in-line between the positive terminals of two batteries (one of which is connected to an alternator, typically a starter battery) and offer several benefits when compared with traditional split charge systems that utilise a Voltage Sensitive Relay (VSR) or heavy duty alternator-triggered relay.
Also you should never connect a second battery to a smart charge system unless it is designed for it. Even jump starting can cause issues and not by voltage spikes some systems need to have the correct type of battery on that vehicle to maintain the system, it is that critical.
Battery-To-Battery chargers allow you to charge an auxiliary / leisure battery from your alternator whilst driving. They are installed in-line between the positive terminals of two batteries (one of which is connected to an alternator, typically a starter battery) and offer several benefits when compared with traditional split charge systems that utilise a Voltage Sensitive Relay (VSR) or heavy duty alternator-triggered relay.
- Direct alternator charging used in a traditional split charge system with a VSR will only achieve around an 80% charge state. VSRs simply allow charge to pass directly from the alternator to the auxiliary battery whereas Battery-To-Battery chargers take the alternator output and boost or reduce it to provide a stable voltage output according to a multi-stage charging profile. This provides a 100% re-charge for your leisure battery in a controlled way and typically achieves it around 5x faster than with direct alternator charging.
- Current flow is limited by the charger's current rating, eliminating potentially damaging high in-rush currents and often allowing the use of smaller connecting cable than with VSR-based split charge systems.
- Using a battery-to-battery charger is the only reliable solution if you intend to re-charge a second battery in a modern vehicle that has an ECU-controlled 'smart' alternator (generally Euro 5/6 compliant engines onward). These have a highly variable voltage output that is often too low to provide a charge or (in the case of regenerative braking systems) so high that it can damage some battery types. Due to this highly variable voltage VSRs are not suitable for use with 'smart' alternators.
Also you should never connect a second battery to a smart charge system unless it is designed for it. Even jump starting can cause issues and not by voltage spikes some systems need to have the correct type of battery on that vehicle to maintain the system, it is that critical.
Indeed, a battery bank I installed in a boat a few months back I got all the batteries within 1mV of each other both during charge and discharge by careful planning of the link wires. That was as good as we could balance the entire bank but because the customer had spent £3000 just on batteries it was worth doing to prolong his investment. It's not simply a case of just wire all the negs together, all the posvs together, job done.
Again correct
Now in the case of @123hotchef he's said he will isolate the batteries overnight, whether he does this with a VSR or just an isolator switch or whatever I don't know but all options have pro's and con's. The better solutions usually cost more money but then you should get a longer service life out of a more expensive setup so in the long run can workout cheaper.
So a bunch of options in order from cheapest to better....
1) diode box
+ dirt cheap
- old tech that has been superseded, usually all batteries suffer undercharging, need to match battery types
2) alternator controlled relay
+ cheap
- 2nd battery will suffer and never get a proper charge, can also affect main battery's life expectancy, need to match battery types
3) Voltage Sensitive Relay
+ still fairly cheap, main battery now gets priority for charging
- 2nd battery still doesn't get a proper charge, still need to match batteries types
4) Shadow charger,
+ 2nd battery finally gets a proper charge, also 2nd battery doesn't suddenly get high amps shoved in it when charging starts, only option when mixing battery types
- expensive, also main battery can be discharged by the shadow charger if its voltage is high enough with engine off (Argh! you solve one problem and create another if your not careful)
123hotchef
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Option two is what I went for, I have the smart style relay, it will also have a switch fitted so that I can switch to the 2nd battery to start the truck in the event battery 1 dies. Also I am going to stick the battery in the tub not under it now. I have thought about it
i end up useing the car quite a lot for work and threatend dual battery but never botherd as i didn't have time i went to local starter alternator shop, stuff the biggest alternator on this that wants to fit so it went from 90 A to 140 A and the biggest fncy batery that would fit in the hole, i have an anderson connector in the grille thats made live via a contactor, its controoled by a switch and voltage sense cuircuit in the car.
i did gets some really fancy new 200AH AGM 12v telecom batterys very cheep that i was going to use on the car but they went in a power crate i made instead 4 of them and one of those fancy mains pass through charger inverters in there was expensive to do and it's heavy but it dosent drink diesel and it's silent, charges in the car van off 12v anderson plug or when mains is fed to it
i did gets some really fancy new 200AH AGM 12v telecom batterys very cheep that i was going to use on the car but they went in a power crate i made instead 4 of them and one of those fancy mains pass through charger inverters in there was expensive to do and it's heavy but it dosent drink diesel and it's silent, charges in the car van off 12v anderson plug or when mains is fed to it
123hotchef
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that works for you but for me i want to be able to leave lights on in the winter at the yard and know i can still start the truck after
Fit LED work lights and give your 2nd battery a easier life
123hotchef
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Fit LED work lights and give your 2nd battery a easier life
they are! well LED light bars but running 3 of them kills the battery in 30 mins
Have you got room for a chore horse generator set then ?
I've one and they are a great bit of kit, it's a 12v 300w single cylinder dynamo designed for charging batteries. As long as you fit a decent exhaust they are quiet and best of all they are electric start by using the dynamo as a starter assuming your battery isn't completely flat.
I've one and they are a great bit of kit, it's a 12v 300w single cylinder dynamo designed for charging batteries. As long as you fit a decent exhaust they are quiet and best of all they are electric start by using the dynamo as a starter assuming your battery isn't completely flat.
normspanners
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In my recovery trucks back in the day (when 12v -12v chargers where not readily available) that I used to have they had twin batteries as std 'mine' had a third 063 as a 'sales' battery in case people needed a battery n wanted to continue their journey ie to get a ferry etc coz we where on the main route to holyhead, but twin/3 different batteries caused all kinds of issues, so I fitted twin alternators in the end one for each battery the second alternator only needs to be small because it is not running the vehicle electronics, to stop any issues the second alternator was on a switched relay to the batteries that flip flopped from one extra battery to the other so when using the second battery as a light source ie beacons work lights it would charge itself naturally when the truck was restarted. I could force it to charge the third battery when needed just to top it up, because that battery HAD to be full at all times.
That meant the main battery was never effected by the second one and was always ready for action but also had a isolator switch to connect all together in an emergency ie -15 middle of the night cold starts.
normspanners
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You can get some denso alternators that are about the size of your fist that will fit as an extra just fit a longer pulley on the std alternator and short 3 rib belt to the extra one that'll give 30/40 amps, more than enough for battery charging. similar to this
123hotchef
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123hotchef
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that is a good idea i need to re locate my alternator anyway it is too low for my liking off road
normspanners
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Also then if you have an issue with the main alternator aflick of a switch and you can get home !!
123hotchef
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that is some nice cable you used too
123hotchef
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just mounted the 2nd battery and my new terminals are a bit loose on the posts
I was thinking about wrapping a bit of lead flashing around the post first what do you think.
there are these available but £4 come on! http://www.ebay.co.uk/itm/Pair-Batt...168420&hash=item33c22f471d:g:Rn0AAOSw-kdXyIg0
I was thinking about wrapping a bit of lead flashing around the post first what do you think.
there are these available but £4 come on! http://www.ebay.co.uk/itm/Pair-Batt...168420&hash=item33c22f471d:g:Rn0AAOSw-kdXyIg0
