ASAP charge controllers

[zoidberg]

The ever-helpful ASAP company offer a range of 'own-badge' charge controllers. I'm installing 3 battery groups: Dedicated Start ( 50Ah/CCA815 ), Primary Services ( 2 x 66Ah/CCA845 ) and, across the footwell, Secondary Services ( 115Ah/CCA? ).... all AGM. The ISKRA/MAHLE Compact alternator is rated at 75A max.

What benefits and problems might installation of this ASAP device bring?

r


Could not much the same be achieved with a simple automotive split-charge relay and use of several keyed battery isolators, at far less cost?

And speaking of battery isolators, simple keyed items cost under £8, while simple rotary On-Off switches cost over 8 times that. Where's the benefit?

 

[PaulRainbow]

The ASAP device is a diode pack, this will suffer voltage losses and is the least desirable method of split charging.

I would simply connect all of the domestic batteries into a single bank, fit each back with an isolator switch, add a 3rd switch for emergency purposes and finally, install a split charge device. For split charging you can use a quality VSR, such as the Victron Cyrix (less money then the Asap diode) or a Victron FET based low loss splitter, which is around £80. Nice, quality, BEP or Durite rotary switches are only about £26.

 

[VicS]

The ASAP device is a diode pack, this will suffer voltage losses and is the least desirable method of split charging.

I would simply connect all of the domestic batteries into a single bank, fit each back with an isolator switch, add a 3rd switch for emergency purposes and finally, install a split charge device. For split charging you can use a quality VSR, such as the Victron Cyrix (less money then the Asap diode) or a Victron FET based low loss splitter, which is around £80. Nice, quality, BEP or Durite rotary switches are only about £26.

But they do say a "very low volt drop", less than 0.2 volt !

The ASAP Electrical range of "Very Low Drop" automatic battery sensed isolators (charge sharers, split chargers) allow you to recharge two or more batteries simultaneously.

They automatically separate connected batteries to prevent discharge or "dumping" of the battery with higher remaining power into the one with the lower power. They will automatically charge the battery which has the lowest charge and then proceed to the other batteries.

The construction is heavy duty, with a rust proof, anodised aluminium case with wide cooling fins, to provide the maximum protection from overheating thus extending the isolator life.

The 'Very Low Drop" characteristic guarantees an extremely small loss of voltage at the exit. The isolator decrease to insignificant levels (less than 0.2V) the voltage drop on the way from the alternator to the battery. This is an innovative feature that differentiates our isolators from those of other manufacturers.

Designed for use with a maximum of one alternator and two batteries.
Provides up to 50A per battery.
Dimensions: 53 x 120 x 100mm.
Terminals are 6.3mm (1/4")
Suitable for 12 volts or 24 volts DC systems (max voltage 200V)

 

[PaulRainbow]

But they do say a "very low volt drop", 0.2 volt maximum !

I saw that, do you think that's a bit optimistic ?

They also claim

They will automatically charge the battery which has the lowest charge and then proceed to the other batteries.

 

[mersey]

There are also driftgate xsplit splitters, frequently found on ebay for good prices. Driftgate were the pioneers of using FETs for near zero loss.

Don't really get the primary and secondary house banks. Most people have just a starter and house bank. What are you putting on them?

 

[Hoolie]

... ...
Don't really get the primary and secondary house banks. Most people have just a starter and house bank. What are you putting on them?

In my case the windlass.

But the boat was originally fitted with a rotary switch together with a voltmeter on the electrical panel to select one of three batteries to run the house services. The PO had torpedoed all that by fitting a 1-2-B switch elsewhere and in reconfiguring the electrics, I restored the three separate batteries configuration. I only use the main house bank position, but at least the other options are there if the main bank goes defunct.

 

[zoidberg]

Don't really get the primary and secondary house banks. Most people have just a starter and house bank. What are you putting on them?

What I've called "Dedicated Start ( 50Ah/CCA815 ), Primary Services ( 2 x 66Ah/CCA845 )" are close adjacent under one quarter berth, and this is about 3 feet max 'cable run' from the alternator. These are Optima AGM ( Red and Blue ) units, which I have, but I reckon 2 x 66Ah is insufficient for Services use. Most battery switchery will be close adjacent.
The Optima RedTop is designated 'starting only'. The BlueTops are designated suitable for 'dual-purpose'. I'm not going to argue with that.

I will put 1 ( or more, later ) Varta 115AH AGM units under the berth on the other side of the boat, and 'single cable run' distance is likely to be 8' or more, to the switchery location mentioned.

Yes, I can connect the whole lot into one battery bank, use it like that for everything until it runs empty, then just sail the boat to anchor, onto trot or alongside, and go to the pub.
Yes, I can have it as one Dedicated Start and one all-joined-up Services or House or Leisure or whatever, but that doesn't help me understand how I get optimum recharge into each unit. My understanding is that one or more of these will be permanently undercharged, and its life will be markedly shortened. And yes, I have several simple keyed isolator switches, enough for each battery unit and/or I can buy/install smarter rotary switches if warranted.

But

I have experienced loss of all nav-kit services, and nav lights, and catastrophic loss of Radio 4 Longwave, etc. on several occasions in fog, on others' boats, and that was if not quite traumatic, then mildly inconvenient at the least. I try to learn from such experience, and I'd really, really like to keep some Services juice in reserve for those unexpected 'oops' moments. There will be times when I will want to sail for several days without starting the engine, but enjoying some PV input to recharge wot the navlights and vhf and Radio 4 Longwave take out. Besides, Milady will want to come along on occasion. She needs to use a 12v 'breathing-assist machine' to sleep, and that's what I'll fit the extra, second 115Ah Varta unit for. That's why I'm interested in being able to keep in reserve the energy stored on the RHS of the boat, or switch it in as wanted. Hence my interest in how best to do it.


This is, for me, not a mere academic debate. I have to listen hard, make decisions and purchases, and fit the kit. Soon or earlier.....

Hence my interest in the ASAP device and my question.....

Designed for use with a maximum of one alternator and three batteries.
Provides up to 50A per battery.

 

[PaulRainbow]

OK, so let's treat the issues of switching and charging separately.

Switching can be done a few ways. Either way you need a separate switch for the engine battery. You could fit on/off switches to each bank (three switches). The engine switch obviously switches the engine on/off. The other two would switch the two domestic banks, they would be connected to the same load connection, so you could choose one bank or the other, or turn both on. You then fit a 4th switch between the engine switch and one domestic switch, for emergency use. If the engine doesn't start, for instance, you turn the emergency switch on and it starts from domestic bank 1, turning domestic bank 2 on will allow the engine to start from all batteries etc.

IMO, the above is a versatile method and it does make use of the switches you already have. But i dare say someone is going to come along and say four switches is too many :beaten:

You could fit a BlueSea dual circuit Plus to the engine and primary domestics, with a matching (size/look wise) BlueSea on/off switch for the secondary domestics, but there is no provision there to independently isolated the primary domestics. So i'm not keen on this idea.

Option three requires that anyone reading this post standing up, sits down before reading any further.........


You could fit two 1-2-B switches :hororr::hororr::hororr: One chooses between domestic banks, or selects both domestic banks. With the other switch, position 1 switches the engine battery on, position 2 has primary domestics connected to it, for emergency use if the engine battery needs isolating due to failure. The "both" position is for emergency starting of the engine in the event of a flat battery, if the domestic switch is set to "both" as well, all batteries will be in parallel for emergency starting only. Anything other than "1" on the engine switch is for emergencies only.

Regarding charging, the ASAP device is still a diode pack and i wouldn't recommend it. IMO, the simplest and best way for this installation is a FET based splitter such as the Victron battery isolator (other makes are available). These are available in versions to charge three banks, frinstance : https://www.batterymegastore.co.uk/victron-arg100301020-r.html

 

[zoidberg]

OK, so let's treat the issues of switching and charging separately.....

.....IMO, the simplest and best way for this installation is a FET based splitter such as the Victron battery isolator (other makes are available). These are available in versions to charge three banks, frinstance : https://www.batterymegastore.co.uk/victron-arg100301020-r.html

Sounds like a plan. Thank you, PR.

I've spoken with ASAP - who were 'unaware' but now reckon they can get the new Victron device, and are considering price point - and also ES-STORE, as well as BatteryMegastore ( whose website fell over for a couple of days ). It seems trade prices from Victron are in a state of flux for some reason, so it's perhaps a matter of 'watch this space' for a few days.

Now I need to plan what physically goes where - or more significantly, what CAN go where - and what ratings the battery fuses should have.

 

[PaulRainbow]

Sounds like a plan. Thank you, PR.

I've spoken with ASAP - who were 'unaware' but now reckon they can get the new Victron device, and are considering price point - and also ES-STORE, as well as BatteryMegastore ( whose website fell over for a couple of days ). It seems trade prices from Victron are in a state of flux for some reason, so it's perhaps a matter of 'watch this space' for a few days.

Now I need to plan what physically goes where - or more significantly, what CAN go where - and what ratings the battery fuses should have.

Rate for the cables, making sure all cables are the same size.

Battery megastore are usually the cheapest for the Victron isolators. There website was a bit flakey, they were moving hosts.