lead calcium battery

Derek thank you fore that advise it says pv panel open circuit voltage =17-23v short circuit current 32 amps-sbc-7130 . so this is not to good for me.

Use a 5A or 10A fuse between the two and if it blows you can't use it.

David thanks for your help power suply voltage 11-14.06 volts@ 35 amps controller 12-16.5 volta @30 amps does this help

Grungle
That is an interesting concept as I have been looking at a simple control of solar at say a constant 15V to allow solar to be connected to a Sterling BB121250 as then the unit can accept all DC Power sources up to 15.5V before safety shut down.

I thought of using an MPPT but cannot get one without the charging algorithms and would be too costly in standard form.

By overcoming the maximum voltage supply the BB12150 can then accept Solar along with alternator power and also any old style transformer charger and turn them into a smart charger.

Ian

Hi lunchbuckett,

It doesn't matter what the voltage range of the reg is but instead what the settings are for the charge algorithyms. i.e boost - 14.4V for example. This is because during boost, the reg provides max current from the source (panels or power supply) until it reaches 14.4V (example). It then holds it at this voltage for a couple of hours during absorbtion and then goes to float.

If the power supply cannot get to the regs boost / absorbtion voltage then it may take a lot longer to charge the batteries. Different regs may do different things so connecting things up and trialing will reveal what yours will do.

At the end of the day however, a power supply that provides max continuous current (key words here) in the 14V range will be pretty good however you will find most will drop their voltage at high currents (i.e. the power supply has a max voltage of 14.1V but as you load it up and start increasing the current draw from it, its voltage drops to say 13.6 - 13.8V or even lower).

If I were you I would only ever consider taking around 20A from the supply to keep the heat down and voltage up. Also you don't say if you have current limiting on the power supply. If it is fused (try putting in a smaller fuse of say 20 - 25A for a 35A power supply), connect it up to the reg and turn it on and see what happens. You will most likely hear a pop as the fuse goes on either the supply or the reg (make sure it is fused as well before doing this).

You can build a simple current limit for the power supply with a pot and some sort of high current FET arrangement. There are plenty of circuits on the web detailing this.

Regards
David

Hi Ian,

I can't take credit for this concept at all though I have thought about it for many years but wasn't inspired to get off my butt until reading Rays efforts (link is on my Solar page).

To get the higher voltages, you will have to go with something with a toroidal transformer as opposed to a standard one. For an increase in current you could go 2 toroidals.

If you had a regulator that has a configurable current limit then you could connect it up to pretty much any power supply such as an alternator without worrying about damaging equipment.

However, a regulator of 30A or above would be more benificial as alternator charging puts in about 30A initially and then tapers off slowly as the batteries voltage increases. With the reg, it will draw a constant 30A until the boost / absorbtion voltage is met so you make more efficient use of the your alternator (not too sure about these ultra modern alternatoers though).

I find that I cannot get anymore than 30A from the alternator. At this time of year (yesterday was one of those days) we head up to solar sites for the QAS and QFRS because of low battery alarms. We connect up the car to the batteries (2V / 1000AHr x 6) to get some charge back in but we always have a Fluke clamp meter attached and find that 30A is the maximum the batteries will get (Navara and a Triton) regardless of revs.

I haven't had much experience with the MPPT but you should be able to make adjustments on the boost / absorbtion and float voltages due to the many different types of batteries out there. I will check with our supplier to find out if this is the case.

Regards
David

David
Im running 2v x1000AH 24 Volt and charging them with a toroidal transformer charger with an excellent algorithm.

I lift the bank with a crane and take it to work places.

Recently I ran at 25A recharge using a 1700is Subaru Inverter generator and got 6.5 hours out of the Subie.

If I ran it at 20A it would have run on echo and got around 11 hrs.

You can do that with a toroidal transformer charger but not a switchmode charger.

I dont know what your 2 Volt cells are but mine are Energel and they can be charged at 29.6V and can take it flat out with temperature compensation.

If you had the same batteries in your 12 V configuration you could boost your alternator voltage to 14.7 and achieve greater charging without the cut back normally produce from astandard alternator.

The MPPT Solar reg use a transformer but like I said not without the charging algorithms.
Ian

Hi Ian,

Wow, that is some serious capacity there!

We use either Concord 2V 915Ahr Batteries which are my preffered battery of choice as they have the highest charge cycles vs battery life (3000-6000 cycles compared to 300-600 for some of the standard AGM batteries) or the Energels in 2V 650Ahr or 2V 1000Ahr varients depending on if a fixed solar site or a trailer.

We have recently bought 2 x Christie Engineering diesel chargers which are rated at 14.0 - 14.8V @ 120A as a redundant system for our Comms sites at mines. We run 15 - 20 x 80W panels, 200 or 400W AirX wind generator and the 120A diesel autostart charger which is controlled by the solar reg (PL60 in most cases). The diesel chargers are my first experience in this area so am keen to get one going for testing.

I will buy in a MPPT reg next week to have a play with as they are supposed to be 20% more efficient than a standard reg so am interested to see how they stack up. Also you can get them in ratings of 60A plus which is great for a site with several repeaters and 30 odd panels (no more splitting into banks and doubling up on equipment). Just have to check up on the specs.

What ones do you use?

We have done a couple of 48V sites using same equipment (Christies Charger & panels but no wind gennie) with good results.

Today I just ordered a Christies 12V petrol charger (5.5 Honda 4 stroke rated at 14.0 - 14.8V @ 120A) so that I am not sitting at a site with the car connected for 4 hours twiddling my thumbs. I hope this will speed things up quite a bit and will accompany me on every callout to a solar site from now on. They follow the same principle you describe of running at higher voltages but have the advantage of a high / low switch to adjust voltage to suit wet cell or AGM batteries.

Great to see someone who has been there and experienced all the joys of solar powered solutions. The only real way to learn is to get in there and experiment with different things.

I love this stuff cause I get to design it, install it and see it work well but can also use it when I go out camping.

Regards
David

David
What DOD are you considering with your cycling figures as the Energel have been tested by CSIRO at 1200 x100% DOD and if your only cycling 25% that would go out to 4800.

The Hayes Gel claims to be the highest with just over 400 cycles at 80%DOD and good AGM 's are around that figure although Ive seen some 300AH AGMs murdered in a high machanical charge and discharge situartion in around four months.

I use Blue Sky and the maximum is up to 30% but that relates to a winter climate which is when you want the extra but overall you should get around 15% but is a bonus and cheaper that an extra panel.

Regards
Ian

Ian, We design our systems around 70% DOD based on around 20 - 30% duty cycle for the repeaters.

A decent emergency can change that though and the duty cycle will climb to 100% (emergency alarm being constantly transmitted) which will drop the DOD pretty quickly. If there is any bad weather around, it will keep dropping hence the need for a backup system.

For non-commercial applications I think 400 cycles is about right if you look after your batteies. However for commercial systems, we try for 7 - 10 years as it gets very expensive when forking out $4k - $5k just for batteries.

We don't do 4wd's or campers / caravans as it is too hard to compete with the likes of Battery World and the like so we stick with the commercial side. We do look after our local 4wd club members though and I have built a decent system for the camper which I always keep tweaking.

Regards
David

David
Good on you.
So basically your cycles are based on say 30% DOD.

Its a hard sell convincing people about quality batteries but we have quite a few vehicles out there with RV Gel and one 5th wheeler in particular a Dryden is set up with 6x650AH x2volt in the van 2x200AH x6volt as the tow aux plus crankers as normal and can run his air con on batteries and rang me from Katherine one Sunday lunchtime saying

"Ive just stopped for lunch in the main street of Katherine and its stinking hot outside so Im lunching in the van with the air con on."

I was please but bloody very envious.

We can do US Coast Guard & ABYC approved Battery Boxes with gel to give 200AH12V with 6V cells ,310AH 12V with 4V cells 450Ah with 2V cells and 650AH with 2V cells.

If people use two twelve volt and or expensive AGM's even through Battery World we can offer a deal and in a designed system a 5year warranty.
Most batteries now for deep cycle use have a 6Months warranty.

I better shut up as I am hijacking the thread.

Regards
Ian

Sorry Lunchbucket.
ian

Pesty
Unless the Ctec has had a charge regime recently installed for calcium I doubt that it can fully charge them and I state that as new chargers coming out now with a specific Calcium selection are stating 15.1V.

The Ctec in my opinion (which means ziff) is not the best but is reasonable value for money.
Ian

Pesty Ian is correct in that the hi-tec will not charge calcium battery fully. my complaint with them is they carnt take the heat and they dont start correctly all the time cheers

The only one I have seen so far is the new Sterling Combi Q and S Inverter Chargers that have a designated charge selection for Calcium and that is 15.1V but unless you wanted a 1600W inverter along with a charger its a bit expensive.
Ian