solar slow charging batteries?

Discussion in 'Tech/Mech General' started by Dazzlin, Oct 26, 2014.

  1. Dazzlin

    Dazzlin Funster Life Member

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    Am I being paranoid?
    2 x 110ah agm batteries. 2 x 100w panels to 1218 controller to ebl99.
    If I use a lot of elec, eg 100w slow cooker on a sunny day for 5 hours, power goes down to 12.0 to 12.2v. Fair enough.
    But then if it is v sunny or even if we drive for 2 hours it still takes several days for them to get back up to 12.8 reading after sun has gone down.
    We never hook up usually so its solar or driving to charge, and its only when using a lot it is slow. Just lights and stuff and stays fully charged.
    Is it me?
    Should they recharge quicker?
    Do I have a sulphation prob?
    Thanks in anticipation.
    Won't get chance to reply til tomoz when we are back on the beach for free wifi again!
     
  2. Snowbird

    Snowbird Funster Life Member

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    That 100 watts is at 240 volts through an inverter that will also lose power. If using the slow cooker, we use it when on the move.
     
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  3. JeanLuc

    JeanLuc Funster

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    At 12.0 - 12.2 volts, your batteries are below 50%. Solar performance will depend very much on time of year and where you are. In late October, I would not expect even 200 watts of solar panels to maintain your battery bank unless you are somewhere near the equator or south of it. You might be seeing 6-8 amps from the panels but the charging voltage will not be high enough to get the batteries near to full charge. Regarding driving, 2 hours will not recharge 100 Ah in two hours even though the EBL99 has a boost system to increase the rate at which the alternator is charging.
    You might consider that the EBL99 is not really suited to AGM batteries - neither are most other multi-stage chargers fitted to motorhomes. The EBL is an IUoU (Bulk/Absorption/Float) multi-stage charger. AGMs require a higher charging voltage during the I and Uo stages than the EBL gives. This may vary a bit by manufacturer, but for example, Varta suggest a peak of 14.8 volts during the 'I' stage followed by constant 14.8 volts during the second 'Uo' stage. This should then fall to 13.8 volts during the float, or 'U' stage.
    The EBL charges at up to 14.3 volts during I and Uo stages, followed by 13.8 volts during the U stage. This is the optimal profile for gel batteries. Despite changing the EBL switch from Gel to Lead-acid, the voltages will remain the same but the timing of the stages is different.
    Ergo, you may never be charging the AGMs fully. This is one of the reasons why many people in the know (I am not an expert) do not recommend AGM batteries for most motorhomes (e.g. Sterling Power and A&N Caravan Services to name two).
    The EBL does work perfectly well with Gels and flooded lead-acid batteries - ideally sealed type in your installation.

    p.s. your example of slow cooker use will drain about 50 Ah from the batteries.
     
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  4. hilldweller

    hilldweller Funster Life Member

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  5. Don Quixote

    Don Quixote Funster

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    Sorry, but there is no way that your 2 x solar panels can charge your 2 x 110 amp batteries, they can topped up BUT not charged as: 2 x 110amp battery at 12.2 is 50% of charge gone so go lower and they will die on you, 50% of 220 is 110amps that your 2 x solar panels have to replace - on average day you might get 6amps per hour = 18 hours of sun directly on the 2 x panels........... so really 3 days without drawing any power at all from the batteries......... is more realistic. Same thing applies to driving ( the charging system (alternator) starts of high then drops to 3/5amps per hour )
    What will happen is you will get some top up from your panels during the day, which shows as 12.7 volts on your display or even shows "fully charged", but they only have, on a good day 6 hours @6amps= 36amps ish = 110+36= 146 amps ( providing you are not using the batteries during the time the solar panels are charging. Now you start the late evening usage of the batteries and you will see that the voltage drops from 12.7 to 12.2. very quickly............
    This is why a good charging system is required to keep the batteries charged and not topped up....

    You also do not say what other items draws power from the batteries - in most cases the average MH'er draws about 6 amps per hour ( 6 x 5 hours 30 amps ) taking into account water pump, fridge, TV, computer, wifi system, satellite box, lights, shower....... the list goes on. As you can see from above the average day you only have 6 amps left out of the 36 amps the sun/solar panels gave you all day.

    Read my posts on here about the B2B, which now that I have fitted and played with, I think it is worth every penny.
     
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  6. Peter & Elaine

    Peter & Elaine Funster

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    Daz you are thinking too much park up and get the booze out
    Go on you know you want to
     
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  7. Dazzlin

    Dazzlin Funster Life Member

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    Its because we are parked up that I am thinking/drinking too much too much.
     
  8. canopus

    canopus Funster Life Member

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    Get some lekky bought you tight gets:rofl::rofl::rofl:

    Or eat salad and put the slow cooker back in the cupboard.
     
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  9. Dazzlin

    Dazzlin Funster Life Member

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    Ta for all your replies.
    I just read everyones claims on their solar set up and how everything is fully charged by the time they get up or at least by lunch that I started thinking!
    I fitted it all to be self sufficient and it is all working. But we use only water pump, a few leds and charge phones, no tv, therefore I had all this power we were not using-I thought, which is why the slow cooker. It may just use too much even tho we are in spain and then morocco again over winter I may be expecting too much.
    It had a new agm battery when we got the van last year which is why I fitted another the same but may look at the ones recommended by a and n or just cheap and cheerful lead acid when back in uk next july.
    would it be worth trying an mppt controller direct to the batteries, not thru the ebl. Got the schaut controller after endless research and advice as the best option!

    Oh well be boring if nowt to wonder about, at least fridge is ok!
     
  10. Wildbill

    Wildbill Funster

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    Have a chat with john of jonandshell if any one can help you he can
     
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  11. funflair

    funflair Funster Life Member

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    If only pulling 10amps from batteries and 200 watts of solar I would have thought that in full sun this should have been supplied mostly by the panels ie very little draw from the batteries, we can recharge in a few hours after pulling about 50 ah from ours batteries with microwave coffee machine hairdryer etc all in the morning and on a sunny day they are ready again in the afternoon, full dun we get up to 20 amps.
     
  12. Peter & Elaine

    Peter & Elaine Funster

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    Daz just a thought disconnect panels and battery then reconnect
    Battery first then panels
    It may just want a reset
     
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  13. eddievanbitz

    eddievanbitz Trader - Funster

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    I still maintain that with a specialist MPPT regulator (after market) that you'll get great results (on average) the end of the Spring, the beginning of Autumn and through the Summer. 200w divided by say 12.5 VDC is 16 amps, so that is the best you'll achieve in middle of the summer, midday. It goes downhill from that date, and approaches that figure up to that date.

    Other than that, the power produced from a solar array will have a holding effect, maintaining batteries rather than replacing the power used when using the motorhome. This is also why I advocate the system be configured to charge the leisure and the engine batteries, so when your not using the motorhome so much, both batteries get topped up.

    I have three 130 watt panels on my motorhome and a mix of other charging equipment, but I will still opt for hook up in the Winter if available and staying more than 24 hours, whereas I wouldn't bother at all in the Summer given the battery bank, B2B and Inverter/charger set up
     
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  14. makems

    makems Funster Life Member

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    Daz, I had a very similar problem a couple of years ago. I thought I could run the Remoska while driving to do some jacket potatoes. It just about flattened the batteries completely.
    Despite having plenty of solar panels and being in Portugal in good sunny weather, after a couple of days the batteries were still not getting back to anything like full health
    After good advice on here I admitted defeat and found a place with EHU. 24 hours later batteries were fully charged and pretty much stayed that way thereafter as they just needed topping up from then on.
    Maybe we will bump into you somewhere in Morocco.
     
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  15. JeanLuc

    JeanLuc Funster

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    If you read the A&N website section on Schaudt EBLs and Solar, you will see why it is a good idea to have a dedicated solar regulator plugged into the EBL rather than connecting directly to the batteries. Apart from the benefit of being designed to work together, you get the starter battery charged too. If you really want a MPPT regulator, Schaudt have just introduced one - it is called LRM1218

    upload_2014-10-27_17-20-13.png
    I shall stick with the LR1218 (PWM) as I have found it perfectly adequate with a 135 watt solar panel. We spent six weeks in France and Italy (mid-Aug - end Sept) and relied on the panel (plus driving). One night after about four weeks, the system shut down due to low voltage. I had been using more 'juice' than normal that day. It may be that the 2 x 110 Ah Elecsols are now on the way out after six years, but it could also have been a perfect example of solar power simply failing to fully charge the batteries up to 100%. After about 18 hours on hook-up we travelled on with no further problems.

    Regarding battery type, I was considering the advice on the A&N website about using Varta Silver Dynamic. I am sure the guys really know their stuff and have done a lot of research, but I decided to give Varta UK a call. They were delighted that A&N are promoting their products, but advised me strongly to go for the Varta LFD90 batteries which are described as Professional Dual Purpose sealed Lead-Acid. Varta would not recommend the Silver Dynamic for motorhome habitation use, indicating that they are the people who have to deal with warranty claims!

    An earlier poster suggested disconnecting the solar panels, then disconnecting the EBL from the batteries (this can be achieved by switching the EBL off and on at the main switch on its front panel. The EBL99 should not require this, but if you have the LCD control panel (as opposed to the older twin needle gauge panle that I have) that might need resetting. I have no knowledge about how to do this.
     
  16. Dazzlin

    Dazzlin Funster Life Member

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    Thats what I thought but even in full sun it is v slow charging.
     
  17. Dazzlin

    Dazzlin Funster Life Member

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    Thanks.
    We have the twin needle gauge. I would have reset it all when I unplugged the 1218 from the ebl (after disconnecting the panels) and wired the solar controller outputs directly to the batteries, bypassing the ebl. I read that as the inverter is connected direct to the battery (what other way is there) the ebl does not know the voltage has been used.
    But it did not make any difference.
    Thanks for the info on the mppt LRM1218
     
  18. JeanLuc

    JeanLuc Funster

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    If you have the twin needle gauge control panel (Schaudt model IT992) then I don't think there is anything to reset. It is only with the later LCD panels that there is an option to set the size of the battery bank on the panel, then the idea is that the EBL will monitor usage and display amount of charge remaining.
    It is true that the EBL will not be able to monitor current used by the inverter - that's just one of the limitations we have to live with. However it will be able to monitor input from the LR1218 (so long as it is plugged into the EBL and NOT direct to the batteries). I think this is a valuable benefit (see comments on the A&N site) and it makes charging the starter battery at the same time a much simpler and cheaper cabling task than having to install a separate Battery Master or similar.

    Regarding the inverter problem, Schaudt recommend an additional battery dedicated to powering it. Probably not a practical solution for most of us, due to space. I shall certainly not be considering it since I only use a 150W PSW inverter occasionally and that is connected directly to the batteries. However, I thought you might care to read about Schaudt's suggested solution.

    upload_2014-10-28_6-18-11.png
     
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  19. Peter & Elaine

    Peter & Elaine Funster

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    That works same as ours in Spain and moroc we have 280 watt and the highest peak charge I noticed was of 25 amps
     
  20. DiggerJon

    DiggerJon Funster

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    EBL, MBBT...? I am totally confused as I have no idea what these are or what they do! All I know is that I had a 100w solar panel fitted with a little black box which I was told topped up the vehicle battery when the leisure battery was full. This seems to work on the mains hookup as well. My measly 80 amp leisure battery seems to cope with my modest demands. Should I be worried that I don't have EBLs, MBBTs etc??
     
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