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Hi
I'm looking to replace my dual battery solenoid which is simply connected when the ignition is on with one of the voltage sensing types.
I'm still trying to figure out if my alternator is 100amp or higher. If higher I won't be able to use the common Redarc SBI12.
I noticed supercheap sell a Ridge Ryder VSR at 140a quite cheap.
Are these things any good? Once you get over 100a rating prices get really silly.
Only ever used vsr's in the past. A benefit over a straight isolator is that they allow the main battery voltage to rise before it connects. You could manually use an isolator to the same effect but the vsr is set and forget.
If you had the budget I'd recommend a Dc-dc charger. An isolator or vsr will always get you home but at least in my experience my batteries never lasted or charged properly when the second was run down(even to safe voltages). I found the problem amplified when I got the patrol with the "smart" alternator. I found if I had substantially different voltages between batteries one would never get a good charge.
Dcdc charger totally changed that. I know for sure now that my start battery always gets a good charge from the alt and if I run the second battery down a bit, it'll get a good charge and bring the batteries into balance.
DC to DC for the win. Smart charger & isolator in one.
DC to DC unit.
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DC to DC isn't in the budget. Looking for a cheaper alternative.
How do these solid state (?) type devices compare to the solenoid type relays?
I'm guessing the Ridge Ryder and Projecta units are solid state, I can't find any internal photos.
OK, but understand that VSR's or ignition switched solenoids are not actually chargers. They are just a switch to parallel the crank & aux battery. The charging is done by the alternator, & if you are charging auxillary deep cycle battery or batteries, it/they will never fully charge giving you less capacity to use at camp, & most folk in this situation end up running the aux battery lower than is good for battery life & as a result have to replace it far sooner . Depending on charging & use a deep cycle battery can last from 12 months to 10+ years. Obviously if you need a new aux battery every year or two, the long term cost is way more than the cost of a dc to dc charger. Saving a bit more now for a dcto dc charger will not only save you money in the long run, it will make camp life better!Quote:
Originally Posted by Jonesy_sa
Be aware that with any lead acid based battery (AGM Gel, or wet batteries) the 'useable capacity' of the battery (if you want it to last) is around 50% of it's stated capacity . ie 50Ah for a 100Ah battery. If charging via a solenoid/VSR the battery wil never get charged beyond 80%. That means only 30% (30Ah on a 100Ah battery) useable capacity ....... if you want a good life from the battery. With a DC to DC charger , you will have your 100Ah aux battery fully charged to 100%, giving you 50Ah to use at camp - getting on for double it's useable capacity to keep you beer cold for longer.
If you are going to buy a VSR - stick with a good brand. Enerdrive & Victron both do VSR's which are cheaper than Redarc & I'd pick them anyday over Supercheap's rebadged Chinese rubbish or Projecta crap. (Some might claim Projecta is good, but I need my electrics to be reliable 24/7 , & have had a poor experience with Projecta stuff. Would never buy it again).
Enerdrive's is a 140amp VSR, & Victron's is a 120amp VSR.
As far as solid state vs Solenoid - I have no idea - have only ever used Redarc VSR's - both 100A & 200A.
One way of saving money but still being able to charge the aux to 100% is to use a VSR AND solar connected to the aux. This will charge the aux up to around 80%, & when stopped the solar will top it up to 100% given sufficient solar & time. Some VSR's are 'dual sensing'.This allows the solar connected to the aux battery to also charge the crank battery once the aux battery is up to full charge, whilst still providing protection against flattening the crank battery. In effect this can give you a bit extra battery capacity to use at camp, so is worth having. I think you pay extra for this with redarc (their dual sensing models have a D suffix), but I think it's standard with the Enerdrive, possibly with the Victron too, but not sure about that.
EDIT - Both Enerdrive's 140A & Victron's 120A have Dual Sensing.
https://enerdrive.com.au/product/140...nsitive-relay/
https://www.victronenergy.com/upload...L-DE-FR-ES.pdf
KSS - Redarc VSR. Works for me. Never had a battery issue. 2 x 120amp wet cells. Solar blanket when camping. 5 - 6 years life from my batteries with good maintenance ( charged with 30amp 240volt smart charger monthly)
There it is, maintained with a good charger your batteries will last. Even better when it's built in.Quote:
Originally Posted by bazzaboy
Alternator O/P won't matter as the Aux Battery will never ever charge at anywhere near 100amps, even flat to about 11.2 volts you would be lucky to get maybe 40 amps initially and quickly taper off to 20 or so as the Charge Acceptance Rate for a standard size Aux (100 to 120 AH or so) .Quote:
Originally Posted by Jonesy_sa
If the Aux is in the Engine bay...as for VSR or Solenoid I suggest Solenoid if you want to winch off the batteries in parallel otherwise VSR for all other purposes.
DC/DC is a waste of money as you will potentially never recoup the small saving in battery costs in the lifetime of the setup if, I stress IF the only charge source is the Alt IE no solar etc.
If the Aux is in the back... and you don't have sufficient wiring capacity DC/DC may be worth considering (budget aside) due to the voltage drop