Charging an Everstart Maxx 29DC Marine battery

[StillDoc]

I have a new Everstart Maxx 29DC Marine battery and a Harbor Freight Cenn-tech 2/10/50 charger. When the charge is complete the voltage of the battery reads 12.51 using a multimeter. As I understand it, that would be only 80% charged with 12.73 volts being 100%.

 

I'm willing to buy a newer, better charger if I need to, but I thought I would ask for comments here first (after spending considerable time searching previous posts).

[Jig Man]

If you aren’t using the 10 setting already switch to it and see if it brings the voltage up.

[Johnbt]

I think I'd consider getting a digital smart charger - Schumacher, NOCO, etc - and save your Manual charger for something else.

 

I looked at the reviews on your charger there are something like 550 bad reviews (a 1 or 2) out of 4,000+ total reviews. 

 

A smart charger will have four phases - Bulk, Acceptance, Float & Equalization.

Here's a short article on chargers.  www.westmarine.com/WestAdvisor/Selecting-a-Battery-Charger

 

Fwiw, I have an old metal Schumacher about like yours, a tiny metal maintainer that must be 30 years old, 2 old blue plastic Schumacher smart chargers (used to have 3, one quit) and a new 3-bank Minn Kota MK330pc. Also, fwiw, I've had 6 of the big Everstart Maxx and my friends still use them. I have Duracell AGM now.

[GaryH]

Digital smart charger time.

[StillDoc]

11 hours ago, Jig Man said:

If you aren’t using the 10 setting already switch to it and see if it brings the voltage up.

Thanks for the suggestion Jig Man, but I did try that. Still ~80%. Then I switched it to 2 amp and reset the charger by taking one of the clamps off then back on. Gage went to 100% and green light came on after about 5 min. Still registering only 12.54 volts.

 

I think I will take  the advise of GaryH and Johnbt and get a digital smart charger. Thanks so much for the comments!

[70diesel]

I completely agree about the smart charger. I used the type of charger you have and always had problems with batteries going bad or not charging fully. Bite the bullet and get a smart charger. If you only have 1 battery I would recommend the NOCO Genius. It can charge all types of batteries then goes into trickle mode when it's done. I had the G7200 (which can also charge 24v) but I don't think they make it anymore but with some searching you can find it for around $100. Otherwise get any NOCO to suit your needs.

[K1500]

Are you using one of the red Harbor Freight free multimeter to test the battery charge?  The ones I have are been far enough off they were worthless for testing batteries for ‘state of charge’.  They are ok for continuity or voltage on/off, but are untrustworthy for anything that requires an actual accurate reading. 

[StillDoc]

On 1/29/2021 at 11:32 PM, K1500 said:

Are you using one of the red Harbor Freight free multimeter to test the battery charge?  The ones I have are been far enough off they were worthless for testing batteries for ‘state of charge’.  They are ok for continuity or voltage on/off, but are untrustworthy for anything that requires an actual accurate reading. 

I'm not using that one, but I think the one I have is likely inaccurate. I ended up getting the Schumacher Model #SC1360 for $64 at Lowes ( https://www.lowes.com/pd/Schumacher-Electric-15-Amp-6-12-Volt-Car-Battery-Charger/1000577617 ) and it reads 12.8v at 100% charge while the volt meter reads only 12.5. So far, I'm happy with the charger.