Hi Condor 22 Ian looking for some info on my 105 AGM battery I've just set this up with a 140w solar panal, I bought a Engil fridge , freezer ,and a small 16 in tv,I thought my full charge on the battery was 12.9v when I used it for the first time with solar set up in full sun it went to 15.4 then it came down slowly to. 12.9 after I turned my fridge up thinking it was over charging so I better use some power up,I got through the next day on 12.9 -12.4-6 ,when I got home I put it on a smart charger to charge to full and it charged to 12.9 then the charger turned of at full charge ,so my question is how do you know what full charge is.Thanks
How full is a battery
- Thread starter 300
- Start date
Help Support Prospecting Australia:
condor22
Mike
300
Firstly what kind of controller do you have on you panel? and, how big is the Engel?
I've just replaced the Gel in my Caravan with a 120AH Full River AGM. I have 3 charging options, a 15A Projecta Intelli Charge for 240VAC charging and a Redarc BCDC1220 20A smart charger for DC-DC charging (i.e. when charging from the car). I also have solar charging via a folding panel I can connect to the van.
Firstly let me say that the voltage across a battery will vary when charged from whatever you use to charge between load and no load. The voltage will drop when under load and also when using a smart charger, depending in what stage it is in, i.e. boost, absorption and float.
The best way to find out what each of your charging options are doing is to start with a fully charged battery, let it rest for a couple of hours if not overnight. when checked a good condition battery should give you a voltage of 12.9V. Then run your Engel for 24 hours on a moderate day, it should use about 25AH. Do this without any solar or other charging. Your battery is still at 75%+ and should read 12.5 to 12.6V if lower than this, it may be on its way out.
Next, having used at least 25% a smart charger will go into bulk charge mode, until eventually in float. Both my AC and DC-DC chargers charge at about 14.5 to 14.6 in absorption and then drop to about 13.9 in float.
Your panel output of 15.2 is in my opinion too high and a charge from an alternator is not high enough at 13.8 which most are. AGMs are very different to a starting battery and need charging properly.
As I have said several times in other threads, voltage is only a guide. A battery monitor such as the ones I use (BM PRO) measure amps in and amps out, indicate the result of both and the state of charge. But not cheap at $299, but cheaper than replacing a battery too often.
Firstly what kind of controller do you have on you panel? and, how big is the Engel?
I've just replaced the Gel in my Caravan with a 120AH Full River AGM. I have 3 charging options, a 15A Projecta Intelli Charge for 240VAC charging and a Redarc BCDC1220 20A smart charger for DC-DC charging (i.e. when charging from the car). I also have solar charging via a folding panel I can connect to the van.
Firstly let me say that the voltage across a battery will vary when charged from whatever you use to charge between load and no load. The voltage will drop when under load and also when using a smart charger, depending in what stage it is in, i.e. boost, absorption and float.
The best way to find out what each of your charging options are doing is to start with a fully charged battery, let it rest for a couple of hours if not overnight. when checked a good condition battery should give you a voltage of 12.9V. Then run your Engel for 24 hours on a moderate day, it should use about 25AH. Do this without any solar or other charging. Your battery is still at 75%+ and should read 12.5 to 12.6V if lower than this, it may be on its way out.
Next, having used at least 25% a smart charger will go into bulk charge mode, until eventually in float. Both my AC and DC-DC chargers charge at about 14.5 to 14.6 in absorption and then drop to about 13.9 in float.
Your panel output of 15.2 is in my opinion too high and a charge from an alternator is not high enough at 13.8 which most are. AGMs are very different to a starting battery and need charging properly.
As I have said several times in other threads, voltage is only a guide. A battery monitor such as the ones I use (BM PRO) measure amps in and amps out, indicate the result of both and the state of charge. But not cheap at $299, but cheaper than replacing a battery too often.
condor22
Mike
As I said Redfin, it is a guide, but the chart you have posted is, I think for a CCR start battery. Here's the one for an AGM, it is very different. 
condor22
Mike
The actual voltages will vary with ambient temperature also, i.e. mine holds at about 12.9V a day or so after I switch the charger off @ about 25C. They will also lose about 3% per month in self discharge if not on charge. Over a period of time this equates to cycling the battery without even using it if you periodically top up. That's why I leave mine on charge 24/7 at home, which AGMs prefer. Using a good smart charger will condition the battery by leaving it on float when under no load and every 21 days the charger cycles to condition and check the battery.
Condor sorry for no info , the battery is a Fullriver DC105a/h its from USA cost over $300 so it's not a cheepy and its new 1wekend use.My solar is Morocrystaline details on back, max power 70wp open circuit 22.7v max power v 18.8v my smart charger is a Projecta 12v 15amp 7 stage unit ,I also charge with the Alternator.My Engil fridge is a 38/40 lt they said it runs on about 2.5 amp or less p/h.I am doing that fridge test now I'll check tomorrow my battery usually sits on 12.9 when not using I also have a Ishto battery and Alternator tester. Thanks
condor22
Mike
300
Ok, you are running the same Projecta I am, that's good. The fridge, (BTW it is spelt Engel, not Engil) is rated at 2.75 amps and will react similar to mine, in that;
It will cycle when on at 2.75 amps or there abouts for about a 1/3 of the time in an ambient temp 25C. So about 25AH in 24 hours. On a hot day 40C or so, it will use that in 8 hours during the heat of the day and probably near another 25AH early morning, evening and overnight, so say 50AH.
I think the issue is with your panel, many folding panels have an inbuilt regulator which is fixed on to the back of one of the panel halves. They are not the best of regulators as their charging algorithm is a one stop shop for several types of battery. Unfortunately they don't look after any of them properly.
In my opinion, you have 2 options to fix any shortfall.
1. De wire the panel regulator and buy a decent regulator and rewire, or
2. Charging from the alternator is not good for an AGM, so if you use something like a Redarc BCDC1225 DC to DC charger when driving. The 1225 is also a solar regulator and has the correct algorithm, so dewire the panel reg and feed panel output to the 1225.
The 2 critical things is to know what you are using and replacing otherwise it's guesswork as to your batteries state of charge and charging properly from all sources.
There is no point looking after a battery on 240 with a good smart charger, then under charging from the alternator and overcharging from solar. Option 2 will fix both of these issues.
Hope this makes sense
Ok, you are running the same Projecta I am, that's good. The fridge, (BTW it is spelt Engel, not Engil) is rated at 2.75 amps and will react similar to mine, in that;
It will cycle when on at 2.75 amps or there abouts for about a 1/3 of the time in an ambient temp 25C. So about 25AH in 24 hours. On a hot day 40C or so, it will use that in 8 hours during the heat of the day and probably near another 25AH early morning, evening and overnight, so say 50AH.
I think the issue is with your panel, many folding panels have an inbuilt regulator which is fixed on to the back of one of the panel halves. They are not the best of regulators as their charging algorithm is a one stop shop for several types of battery. Unfortunately they don't look after any of them properly.
In my opinion, you have 2 options to fix any shortfall.
1. De wire the panel regulator and buy a decent regulator and rewire, or
2. Charging from the alternator is not good for an AGM, so if you use something like a Redarc BCDC1225 DC to DC charger when driving. The 1225 is also a solar regulator and has the correct algorithm, so dewire the panel reg and feed panel output to the 1225.
The 2 critical things is to know what you are using and replacing otherwise it's guesswork as to your batteries state of charge and charging properly from all sources.
There is no point looking after a battery on 240 with a good smart charger, then under charging from the alternator and overcharging from solar. Option 2 will fix both of these issues.
Hope this makes sense
Hi Condor 22 I did the fridge battery test 24hrs battery tester said 12.5 a/h looks like battery is fine,the car battery charger Redarc bcdc in your car does that go in the car12v plug so you don't use the alternator at all,also is it best to leave my Projecta 7stage smart charger on 24/7 I was told elsewhere that it wasn't needed to do that.Condor 22 thankyou for your help this is all new to me.
condor22
Mike
Hey 300, Read this, the first DO says to keep it on trickle charge, the Projecta will do that. Read the rest it has good info.
http://www.batterystuff.com/blog/agm-battery-best-practices.html
Have a look at the Redarc web site for the BCDC1220, I've wired mine similar to that, if you want to know exactly how I'll send you a wiring diagram. Mine is slightly different in that I had a 70A continuous ign controlled solenoid installed for my caravan hot wire and I tapped off of that for the Redarc. So the Blue IGN wire is connected to the positive input, because as soon as IGN is off the solenoid breaks and the Redarc is isolated from the vehicle battery.
http://www.batterystuff.com/blog/agm-battery-best-practices.html
Have a look at the Redarc web site for the BCDC1220, I've wired mine similar to that, if you want to know exactly how I'll send you a wiring diagram. Mine is slightly different in that I had a 70A continuous ign controlled solenoid installed for my caravan hot wire and I tapped off of that for the Redarc. So the Blue IGN wire is connected to the positive input, because as soon as IGN is off the solenoid breaks and the Redarc is isolated from the vehicle battery.
condor22
Mike
300, I may be confusing you a little because I have 2 batteries in different environments, one in the car and one in the van. The method of charging and use differs;
VAN - I leave the Projecta on when ever in my drive or on a powered site or if charging from generator. It has its own Redarc 1220 for when driving, because my van 3 way fridge is on 12V from the van battery, it uses about 14A, but the Redarc will charge at 20 max. I also have the capability of charging from solar.
CAR - I do not charge with the Projecta (it's hard wired to the van) The car has an auxiliary battery, which is charged by another 1220 in the car when I'm driving. Because I drive pretty well every day and don't always have the Engel on, it gets charged or trickle charged as needed by the 1220. I can also plug in solar if camped up. Or run a generator through a smaller 8A 240V charger if needed.
Both the Projecta and Redarc devices will "Float" (maintain) correctly as they are both Smart chargers.
VAN - I leave the Projecta on when ever in my drive or on a powered site or if charging from generator. It has its own Redarc 1220 for when driving, because my van 3 way fridge is on 12V from the van battery, it uses about 14A, but the Redarc will charge at 20 max. I also have the capability of charging from solar.
CAR - I do not charge with the Projecta (it's hard wired to the van) The car has an auxiliary battery, which is charged by another 1220 in the car when I'm driving. Because I drive pretty well every day and don't always have the Engel on, it gets charged or trickle charged as needed by the 1220. I can also plug in solar if camped up. Or run a generator through a smaller 8A 240V charger if needed.
Both the Projecta and Redarc devices will "Float" (maintain) correctly as they are both Smart chargers.
condor22
Mike
300, I guess what I didn't ask is if your battery is in your car temp or perm or elsewhere......
The key thing with a deep cycle, in particular an AGM is that you view them in this instance, in 3 differing installs -
1. In a van/camper that sits in a drive much of the time, which needs to be left on charge. (Projecta) and if using to power the fridge when driving a Redarc.
2. Permanently installed in a car, in which case a Redarc or similar DC-DC when driven most days is good enough.
3. Temporary install in a car when you go on trips, in which case you use the Redarc when installed and the Projecta when you take it out.
In any of these solar is an option providing you have a decent regulator that does the same thing as a smart charger. Some of the cheaper panels don't have good regulators. Here's some info on separate regulators you can buy.
Pulse Width Modulation Solar Regulator - PWM
Are the most common type of battery charging technology. Theyre able to prolong battery life and reduce heating and sulphation while charging. PWM charge controllers are usually cheaper than their Maximum Power Point Tracking counterparts but work at around a 70% efficiency rate when transferring energy from the panels to batteries.
Maximum Power Point Tracking Solar Regulator - MPPT
A more recent technological advancement, Maximum Power Point Tracking regulators offer the same battery life-prolonging properties as PWM regulators but with a higher efficiency rate of 95 to 97%. They do this by transforming excess voltage to the right level with an increase in current, rather than by simply clipping it. While they may be the slightly more expensive option, the increase in efficiency offered by MPPT charge controllers makes them well worth the money, especially if you rely heavily on solar for your power needs.
MPPT are much better and also cost more, but will give about 25% more charge from the same panel.
The key thing with a deep cycle, in particular an AGM is that you view them in this instance, in 3 differing installs -
1. In a van/camper that sits in a drive much of the time, which needs to be left on charge. (Projecta) and if using to power the fridge when driving a Redarc.
2. Permanently installed in a car, in which case a Redarc or similar DC-DC when driven most days is good enough.
3. Temporary install in a car when you go on trips, in which case you use the Redarc when installed and the Projecta when you take it out.
In any of these solar is an option providing you have a decent regulator that does the same thing as a smart charger. Some of the cheaper panels don't have good regulators. Here's some info on separate regulators you can buy.
Pulse Width Modulation Solar Regulator - PWM
Are the most common type of battery charging technology. Theyre able to prolong battery life and reduce heating and sulphation while charging. PWM charge controllers are usually cheaper than their Maximum Power Point Tracking counterparts but work at around a 70% efficiency rate when transferring energy from the panels to batteries.
Maximum Power Point Tracking Solar Regulator - MPPT
A more recent technological advancement, Maximum Power Point Tracking regulators offer the same battery life-prolonging properties as PWM regulators but with a higher efficiency rate of 95 to 97%. They do this by transforming excess voltage to the right level with an increase in current, rather than by simply clipping it. While they may be the slightly more expensive option, the increase in efficiency offered by MPPT charge controllers makes them well worth the money, especially if you rely heavily on solar for your power needs.
MPPT are much better and also cost more, but will give about 25% more charge from the same panel.
Similar threads
Latest posts
-
-
-
-
Northern Michigan United States of America possible magnetic meteorites- Latest: Joshua Brown
-
-
-
