PV solar system charging voltage low

FloridaFlyer86 wrote:

NinerBikes wrote:
Rough rule of thumb, for every AH you have at 12V, you need at least 1 to 1.5 watts of solar panel to charge it. Since you have 440AH in storage capacity in your batteries, you'll need about 440 to 660 watts of solar panel to get the job done.

That's about what I want to have, and hopefully will make it happen soon. Should have mentioned the PV panel is not the only charging source, I have been using my Honda 2000 gen with the stock converter but of course the crappy converter is only giving me 13.5 volts so is also not doing a good job of charging either. I have an Iota DLS-45 charger arriving UPS this afternoon, should have ordered it before getting the new batteries but I wasn’t sure if it would meet my needs or if I would need a fancier Xantrex or other charger. After research it looks like the DLS-45 feature of having a jumper wire to force 14.2 volts should be fine for morning and evening charges with a generator.

full_mosey wrote:


I have experience with the SS gen 2 controllers.

Yours is working fine. It is a two stage charger(no 3rd float stage). During Stage-1,bulk, it charges at the panel ISC depending on the panel tilt. The Volts then increase to 14.4 where stage-2, PWM, kicks in and current is tapered down. Your solar panel is not supplying enough daily Amps to raise your battery bank to 14.4V and is not reaching stage-2.
The 12.5 resting Volts is too low and proves that the bank is not being recharged daily. This is an undercharge situation that will result in sulphation and ruin the bank.
Consult the mfgrs manual.
HTH;
John

That makes sense, I see now that I didn’t understand the SS operation… so I haven’t even been getting into PWM mode. That would explain why I did see 14.4V with the older, smaller battery bank. Hopefully after installing the DLS-45 and spending some time charging at 14.2V I can use the PV system as I intended, to top off charge after bulk charging with the gen. I’ve only had the batteries a little over a week and been careful not to discharge them too low, according to the TM-2025 I haven’t gone below 75% and that was only a couple times. So hopefully I haven’t done irreparable damage!

The jumper wire forces the Iota to output 14.8V,until the battery sees 14.6, or the Iota senses that the battery is charged enough to take up to 14.6V.

Make sure you install that jumper wire on your Iota and leave it in place, and it will do a good job on getting your batteries closer to being topped off.

You didn't mention which amp model Iota you bought.