navitron
 
Renewable Energy and Sustainability Forum
Welcome, Guest. Please login or register.

Login with username, password and session length
News: Anyone wishing to register as a new member on the forum is strongly recommended to use a "proper" email address - following recent spam/hack attempts on the forum, all security is set to "high", and "disposable" email addresses like Gmail, Yahoo and Hotmail tend to be viewed with suspicion, and the application rejected if there is any doubt whatsoever
 
Recent Articles: Navitron Partners With Solax to Help Create A More Sustainable Future | Navitron Calls for Increased Carbon Footprint Reduction In Light of Earth Overshoot Day | A plea from The David School - Issue 18
   Home   Help Search Login Register  
Pages: [1] 2   Go Down
  Print  
Author Topic: Trojan, Crown or Powerline?  (Read 3953 times)
Pord
Jr. Member
**
Offline Offline

Posts: 57


« on: September 18, 2017, 12:27:39 PM »

Afternoon folks

I'm currently putting together an offgrid PV system. I just have the batteries to buy and I would really appreciate your thoughts on which to choose.

The system is 1kw 24v, 4 x 250w panels with Victron kit. I want a battery bank of 200ah minimum, giving us 2 to 3 days hold over (our needs are very low). This will power our static caravan while we build an offgrid house.

This will be my first PV and battery system, so will be something of a trainer set. I've narrowed my choices to:

Trojan T105 (565)
Crown 27DC105 (510)
Powerline T105 AGM (525)
Powerline T105 FLA (490)

Prices are inc VAT and delivered.

Has anyone experience of Powerline (made by Trojan apparently)? Are the AGMs worth the bit extra? Every penny is a prisoner, so any saving is welcome.

One last question - is there a definitive reference book/manual on basic battery maintenance?

Thanks.

Logged
Scruff
Hero Member
*****
Offline Offline

Posts: 1230



« Reply #1 on: September 18, 2017, 12:48:09 PM »

Crown CR-220 FLA 6v x4

Are the AGMs worth the bit extra?

Absolutely not. They're non spillable, non serviceable designed for safety on boats and aircraft and found popularity by means of being reassuringly expensive.
Flooded batteries will last 3 times longer. Give you more power per cycle, charge faster and forgive you for over-voltage & over-charge.


One last question - is there a definitive reference book/manual on basic battery maintenance?


Not really but I can write one.

Get battery, charge it to specific gravity 1.275 per cell once every 3 weeks...aim for once every week. Refrain from discharging below 50% state of charge but design the system to use only 10% capacity per day.

Charge to 29.6V + temperature compensation absorption.

When you buy a charger and find it doesn't charge your battery to 1.275 per cell, chuck it in the bin and get something better (have a very large bin on standby). If the charger you are buying doesn't have a 29.6V setpoint don't buy it.

Add water as needed. Never expose the plates to air and only top up electrolyte when the battery is fully charged.

Get a shunted battery monitor for the system that displays state of charge as a percentage.

The end.
« Last Edit: September 18, 2017, 02:07:23 PM by Scruff » Logged
DaveSnafu
Full Member
***
Offline Offline

Posts: 247


« Reply #2 on: September 18, 2017, 07:03:59 PM »

What he said.
Logged

Proven wt2500,24v batteries,running house,navitron solar thermal integrated tank, 10 x 210w eclipse italia pv, wbs,
offthegridandy
Hero Member
*****
Offline Offline

Posts: 1002



« Reply #3 on: September 18, 2017, 08:16:29 PM »

Or here's a place to go and get a lot of homework/reading.  http://batteryuniversity.com/

Andy

Logged

8 KVA Lister TS2 Startamatic Genny
24 Volt 1000amp battery bank
Outback VFX3024
4.6 Kw PV array ground mounted
Outback Flexmax 80
2 X Flexmax 30 PV CC
2.5 Kw WT H Piggot design 4.5 Mtr Dia AC coupled
12 Mtr free standing Tower.
u/floor heating from oil boiler cross linked to 12 K wood stove
RIT
Hero Member
*****
Offline Offline

Posts: 2072


« Reply #4 on: September 18, 2017, 08:27:48 PM »

One thing you do not say is how long you expect to stay in the static caravan or if you expect to continue to use/expand the storage solution once you are able to move into the house.

These values are likely to have a major impact on how much you should invest in the setup.
Logged

2.4kW PV system, output can be seen at  - https://pvoutput.org/list.jsp?userid=49083

Why bother? - well, there is no planet B
Pord
Jr. Member
**
Offline Offline

Posts: 57


« Reply #5 on: September 19, 2017, 08:53:37 AM »

Thanks all.

We reckon we'll be in the static for 2 years. After that we'll either incorporate some of the pv kit into our larger system for the house or use it elsewhere on our site such as a workshop or bothy. These batteries are primarily a shorter rather than longer term purchase.

Has anyone any experience at all of Powerline? On paper the T105 gives best value.
Logged
Scruff
Hero Member
*****
Offline Offline

Posts: 1230



« Reply #6 on: September 19, 2017, 12:44:38 PM »

CR-220s are better batteries than T-105s
Logged
Pord
Jr. Member
**
Offline Offline

Posts: 57


« Reply #7 on: September 19, 2017, 09:54:58 PM »

Thank you Scruff, really great to have very definite advice. The CR-220s have been ordered, at a good price too. I'm on target for a sub-1500 1kw system with 220ah battery bank.

To be honest, though, most off your beginner's guide to battery maintenance advice may as well have been written in Urdu. I realise this stuff is second nature to you, but at this stage it's anything but to me. I've come to realise that this is the great challenge to people like me who aspire to (and indeed are living) an offgrid lifestyle. The technology is still frankly intimidating, and seems to require quite a high level of technical knowledge. It reminds me of the early days of computing, compared to now when we switch on a tablet or smartphone and it just works.

Anyway, on to the challenge of not ruining my lovely new battery bank!



Logged
Scruff
Hero Member
*****
Offline Offline

Posts: 1230



« Reply #8 on: September 19, 2017, 10:08:10 PM »

If you get a Hydrometer, battery monitor and MorningStar controllers you won't go wrong.

I've not been impressed by Victron, the charger I have from them can't do better than SG 1.255
It's been gathering dust beside a Sterling since I bought it.
Yurp pretty steep learning curve but as long as you are getting the battery to 1.275 every few weeks it'll last a decade.



I try to avoid inverters as much as possible they're system parasites, do as much as you can with truck power supplies and you'll get a much more efficient system.

Put on a cuppa and dig in here and here.

Good hunting!
« Last Edit: September 19, 2017, 10:14:47 PM by Scruff » Logged
Pord
Jr. Member
**
Offline Offline

Posts: 57


« Reply #9 on: September 20, 2017, 10:26:09 AM »

Thanks, very much appreciated!
Logged
Scruff
Hero Member
*****
Offline Offline

Posts: 1230



« Reply #10 on: September 21, 2017, 12:14:20 AM »



Happy CR-235s
Left to fend for themselves onna 150W panel anna TriStar for a week after a month of touring.
 Grin
« Last Edit: September 21, 2017, 12:18:01 AM by Scruff » Logged
Pord
Jr. Member
**
Offline Offline

Posts: 57


« Reply #11 on: September 21, 2017, 09:40:18 AM »

Sounds like a great thing! But what is the 113? The label suggests % charge...

Crowns arrive today. Had to laugh when the seller asked if I have 'lifting equipment' to get them off the lorry.
Logged
Scruff
Hero Member
*****
Offline Offline

Posts: 1230



« Reply #12 on: September 21, 2017, 10:09:29 AM »

I've set the TriMetric to L3 Advanced with auto-reset when fully charged set to off and battery efficiency to 100%. This way I can see the meter drift and puekert compensated efficiency.
There's reasons that no battery monitor is 100% accurate. This way I can see the drift and compensate for cycle depth and duration with reference to specific gravity, water level, nominal operating temperature, average C-rate, charger CC input, resting voltage, battery age & battery health I know exactly where the battery's at.
113% is % charged so 132Ah replenished after a cycle bottoming @ 55% SOC (-110Ah) over a week (since last full charge). Nought I've tried but MorningStar will get my battery to tippy top SOC.

Which leads me to believe that this "you must charge lead acid 100% every week" is a myth rule of thumb. Absolutely you must charge lead acid every week if you use an off the shelf charger that only gets your battery to SG 1.260. How and ever I've not noticed any deterioration in my cells running up to 6 week deep cycles provided I can get them to SG 1.275 on a semi-regular basis.

My battery is freshly (over)watered too, the electrolyte is weaker and it's less efficient but I'm happy to sacrifice performance for a coupla months so I don't have to water them again until Spring.

I reset the meter manually with a button press when I start a new depletion cycle.
This is a direct-drive sunlight powered post.  Cool


* TM-2025 Users Instructions9-11-12.pdf (216.03 KB - downloaded 132 times.)
« Last Edit: September 21, 2017, 10:29:13 AM by Scruff » Logged
Scruff
Hero Member
*****
Offline Offline

Posts: 1230



« Reply #13 on: September 21, 2017, 10:19:46 AM »

Crowns arrive today. Had to laugh when the seller asked if I have 'lifting equipment' to get them off the lorry.

Hmmmm...factory fresh premium lead...



They are heavy lumps get a ratchet strap tail and thread it through the handle loops so you don't have to bend your back to move them.
Charge them before you commission them, then take note of an SG reading for a basline and to make sure the fill level is correct (no electrolyte lost in transit).
Logged
Pord
Jr. Member
**
Offline Offline

Posts: 57


« Reply #14 on: September 22, 2017, 02:25:31 PM »

Thanks Scruff. Batteries are safely ensconced and hydrometer on the way in preparation for the next phase. Give it 20 years and I reckon we'll look back on current batteries the same way we now think about steam power...
Logged
Pages: [1] 2   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.20 | SMF © 2013, Simple Machines
SMFAds for Free Forums
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!