are these batteries any good???

[dorff]

have two Crown CR-GC150 12v FLA deep cycle 150AH each, connected in parallel so 300 AH available. Run them down with a 4.5amp load, should get about 2000 watts out of the set at 50%soc, but only getting 1200-1500. Less than a year old, never below 50%soc, never not immediately recharged after a 50%soc run down. At 12.2v at rest = 50% soc, SG @ 1200. Put a 100 amp load on them and voltage sags immediately to 11.2v.

When I recharge them with Xantrex inverter/charger at 35amps at completion of charge cycle, battery voltage ok, but SG at 1175. Hit with a 2 hour 15.2v 15amp equalization cycle, and I can get SG to 1250. Spec is 1275, which I can get them there with their spec'd equalization cycle of 16.2v for 4 hours at 15amps. (spec for one battery is 5amps, so with two i push to 15amps)

But next 4.5 amp load/recharge cycle, they only get back to SG 1175...

Does this sound like a battery issue or a charger issue?

[Bala]

Batteries in parallel is not ideal.

Try equalising each separately to see if you can get the SG back up.

[LETitROLL]

have two Crown CR-GC150 12v FLA deep cycle 150AH each, connected in parallel so 300 AH available. Run them down with a 4.5amp load, should get about 2000 watts out of the set at 50%soc, but only getting 1200-1500. Less than a year old, never below 50%soc, never not immediately recharged after a 50%soc run down. At 12.2v at rest = 50% soc, SG @ 1200. Put a 100 amp load on them and voltage sags immediately to 11.2v.

When I recharge them with Xantrex inverter/charger at 35amps at completion of charge cycle, battery voltage ok, but SG at 1175. Hit with a 2 hour 15.2v 15amp equalization cycle, and I can get SG to 1250. Spec is 1275, which I can get them there with their spec'd equalization cycle of 16.2v for 4 hours at 15amps. (spec for one battery is 5amps, so with two i push to 15amps)

But next 4.5 amp load/recharge cycle, they only get back to SG 1175...

Does this sound like a battery issue or a charger issue?

One of the problems with batteries in Parallel is that any slight differences in the 2 (always some difference with mass produced products) and they have to constantly charge and discharge each other on a small scale to stay in perfect balance, which will eventually make both equal to the weakest one, and make them wear out sooner. From the numbers you have given things dont seem terribly off, Hitting a 300ah FLA battery with 100a load should cause a big voltage sag (that is 1/3rd the total capacity), also 300 x12v = 3600w, and you say you get 1200-1500w at 50% soc, 1800 is half, so not far off there, and remember all systems have losses so you will never get the full 1/2.

[Mike90250]

When you charge them, are you charging with at least 30A and getting them gassing well ? What has water usage been like, adding lots of water or a pint monthly, or less ???

[dorff]

LETitRoll - I understand that a 100amp draw is huge for a 300AH set, but the voltage sagged immediately to 11.2v with a 50% SOC, I just thought it would hold voltage better for 30 seconds.

Because I'm only drawing 4.5 amps total on the pair of batteries or 2.25 amps per battery, that equates to its 72 hour spec which is 176AH or 2112 watts x 2 batteries * 50%SOC = 2112 watts from the paralleled set. I'm only able to get 1200-1500 watts which is 60-70% of its 50% SOC spec, so something is not right.

Crown's specs for charging are >18amps, but less than 36amps. If the set is paralleled would you not double that to >36, but less than 72amps?

I've charged the set at both 35 amps and 55 amps and i don't see a different outcome, either way I'm still only getting back to 1175 SG.

Very little water addition, maybe a 1/4 inch in each cell over the last couple of months.

So I'm experimenting with some custom charging settings to see if a higher V setting for both the bulk and absorbition will give me an end of charge state at spec SG.

Set the Bulk & Absorb to 15.2v (vs spec of 14.2) and float to 13.8v for 3-4 hours (vs 13.5)

The Recommended Equalization Charge per the spec sheet is weekly at 5 Amps at 16.2v (doesn't that seem high)........would I double that to 10 amps with two wired in parallel???

Any thoughts on the higher custom charge settings (still charging in parallel)? I'm leaving the caps on loose or should I kept them on tight??

If I don't get close to SG then I will try charging each battery one at a time, just doing that on a regular basis isn't going to work for me.

[Matrix]

It's good that you are testing with higher voltages. I have an Conext SW charger, and If I use the Flood Acid setting on my SW charger, it stops and "says" I am fully charged but check the SG and I am not. If I use the custom settings and set the Bulk and Absorb to 29.6v (or 2.46v per cell) which is spec for my 24v system, I get the same as the flood acid setting ... still under charged.

I called Trojan Battery about higher voltages and they told me it will not harm the battery, even using 2.62v per cell. They told me using this higher voltage is way better than under charging the battery and the SG needs to get up to the Fully charged spec.

Here is what I would recommend

if you have some way of adding in custom settings into the Xantrex ...

1. Set your battery capacity / amp hour in the Xantrex to 50 not the AH of the battery if it has this settings
- if the Xantrex is like the SW the charger gets it's end amp termination for absorb from this setting
- I Have found that the SW terminated way too soon if you set it at your battery AH
- Schneider told me this setting used to supposedly end absorb at 2% of what you enter in .- or 2% of your battery bank AH ... but my experience is that it does not. It is more like 3% or more of amp hour
- but if you are using custom settings ... this will allow you to stay in Absorb longer if you set the AH to lower than your actual Battery bank AH
- if you have this setting ... play around with it until you get the end amps for absorb where you want it. If it will go lower than 50 dont hesitate to try it and see if it helps (SW's min is 50 ah)

2. I do not know what the charge output is on your charger (my SW is 90 amps) ... but if there is a setting for charge amp out put and the percent of charge set it so that you get the max charge rate for your batteries. For my 435ah bank I set the charge rate at C/8 (I think that is how you write it) ... or 435 / 8 = 54.4 amps which is the max charge amps for this battery bank.
- since my max amp charge is 90 ... I leave the charge rate at 90
- and set the % of charge at 61%
- which give me 54.9 amps max charge rate

3. I have to use custom voltage settings to get a full charge on my batteries with my SW and set the bulk / absorb to about 31v +/- or 2.59v per cell

4. I then set Float to near the manufacture Absorb rate which is 29.6v or 2.46v per cell . Sometimes I use 28v and some times I will use 29v depending on how long I will let the charger "float"

Again Remember I have a 24v battery bank so your total voltage numbers will be different.


This set up gives my a good solid charge on the batteries. You will have to experiment to see exactly where your sweet spots lie. Your Mileage May Vary

[dorff]

Matrix thanks for the support. Xantrex does not have a battery bank capacity setting and its max charge amperage is 55 amps, 5,15,35 or 55 amps are your choices. No % of charge settings either. So I take it you'd suggest running bulk/absorption at 55 amps.

Do you leave caps on or off when running your higher voltages for the charge cycle.

I've ordered some of those Water Miser Caps that suppposedly alleviates the need to remove the caps when running higher equalization voltages, captures the mist and then it drips back into the battery. At least it avoid the mess from the bubbles. Don't know if they also avoid any evaporation, but I'll try them out for a while and see.

I'll keep playing with the absorb V and see if I can't find a level that gets them back to spec SG after each charge. Thanks

[Bala]

As you are probably aware if you leave the caps acid ends up everywhere, so dont do that.

Incase the breather in the cap is blocked or not sufficient for an equalise undo them but leave them sitting in place.

It may be a pain to do each battery separately at regular intervals but it is your best option for long battery life.

When it comes time for replacing them look at 2 x 6V in series.

[dorff]

well I un-paralleled the two Crown 12v deep cycle 150AH batteries and recharged them separately and got the same results, in that the Xantrex charger said done but the batteries where only at 1.175 SG. Only by bumping the bulk/absorption V to 15.4v could I get them to 1.275 SG. On a lark I also tried recharging them with my Victron Solar Charge Controller and same results, when the Victron went into float, again SG was only 1.175. Batteries are not even 8 months old, maybe only 25 cycles on them, always been very careful about 50% SOC and immediately recharging them after a drain, etc. Doesn't this sound like batteries gone bad? What is my best approach with Crown to get them to consider these batteries as early failures and get them to replace them??