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benethridge's picture
Joined: 5/13/09
Posts: 446
Golf Cart Battery Break-in Period: Discharge or Equalize?

This was interesting. Here we have two highly respected and yet opposing viewpoints. One says to discharge and the other says NOT to discharge, but to equalize first:


If I go with Trojan's equalize philosophy, where would I buy an equalizer? I've googled but it doesn't appear that many people buy this tool.

Having just installed four new golf cart batteries, this is a rather timely issue for me. :-)

Ben Ethridge
Miami, FL
1984 MK1 Hull# 263

Joined: 9/4/09
Posts: 1127

Ben, some chargers have an equalize cycle built into them. Our IOTA does a short equalize every 7 days if there's been no loads/charging on the batteries. Most of the really good chargers have an auto or manual equalize cycle.

Maine Sail
Joined: 2/26/10
Posts: 322


Break in is different from commissioning.. Break in will eventually happen but happens faster if you let the first 10-40 cycles go all the way to 50% before recharging. A commissioning charge is what I do before I install a bank of batteries.

This is what Trojan says about new batteries:

[B][I]*A new deep-cycle battery will not deliver its full rated capacity. This is normal and should be expected as it takes time for a deep-cycle battery to reach maximum performance or peak capacity.

*Trojan’s batteries take between 50 – 100 cycles to work up to providing full, peak capacity.[/I][/B]

Until the batteries are cycled they will not be at full capacity, will not hold voltage as well etc.. I commission charge batteries before installation but this is not the same as breaking them in. Commissioning for me includes about 30-40 minutes at 15+V AFTER THEY HAVE BEEN FULLY CHARGED at 14.4V to 14.8V depending upon the manufacturer. I tend to call this a wake up charge or commissioning charge.

With batteries that will be in series or series parallel I also parallel top balance them. This means I wire them in parallel, as a 6V bank, then charge to full at 7.4V (14.8V if Trojan's). Once full I then push the voltage to 7.6V (15.2V). This ensures each series cell is at the same charge level before I even wire them in series. It also works as a commissioning charge.

The absolute best tool for charging, equalizing etc. IMHO is a bench-top DC power supply. A 30V X 10A or 15A version would be fine. The Mastech EX series are specifically engineered for battery charging and feature over voltage protection. The 3010EX or 3020EX are both excellent.

[B][URL="http://www.mastechpowersupply.com/dc-power-supply/switching-power-supply..."]Mastech 3010EX[/URL][/B]

[B][URL="http://www.mastechpowersupply.com/dc-power-supply/switching-power-supply..."]Mastech 3020EX[/URL][/B]

I use a Mastech 3030EX in my shop:


stu jackson c34's picture
stu jackson c34
Joined: 12/3/08
Posts: 1270

Breaking in New Wet Cell Batteries: [url]http://c34.org/bbs/index.php/topic,6353.0.html[/url]

benethridge's picture
Joined: 5/13/09
Posts: 446

Thanks, everyone.

Maine Sail, I'll probably buy that 3010EX. Only about $150. Seems like it will pay for itself over the years.

Stu, that Ample Power Break-in article says "Let the discharge continue until the battery voltage reaches 10.5 Volts. "

Really? 10.5? Everywhere else I'm reading, it says to never discharge below 12.2 (50%), even on the break-in cycles.

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