Lifeline AGM bank of four w/ 2 older than the new ones

[smokeylew]

Have two 14 month old Lifeline AGM 6v batteries I pulled from my older TT and purchased two more of same to build a bank of four for newer 5th wheel. Older batteries have been well maintained scence originally installed. Connected in series/parallel for 12v and use two 100 watt solar panels for charging.

You think mixing ages will be a problem for this setup? Very expensive to buy two more new ones to match ages of new ones.

Thanks for responding.

[MEXICOWANDERER]

Do
Not
Recharge
AGM
Batteries
With
Less
Than
20% amp hour capacity recharge amperage

If the battery has been discharged more than 60% remaining capacity.

i.e. 200 ampere hours bank capacity. Equals 40 ampere MINIMUM recharge rate.

There is a time constant which seems to kick off after say 10 days of sub minimum recharge. Weekend warriors need not worry. Long-term off-grid, worry.

[Byrogie]

How many total amps will you have? Will you have enough solar?
Typical 4x6 volt = 400+ amps
1 watt per amp rule of thumb.

[smokeylew]

Good suggestions guys. I can always count on great feedback from you all

[MEXICOWANDERER]

Why not prove it to yourself? Charge fully then disconnect all 4. The following morning take voltage readings across each battery. What do you see ? 🙂

[pigman1]

I agree. If you still have some concerns, I'd give Lifeline a call and talk to one of their technical experts. I had an issue with a bank of 6 new lifelines and after talking to one of their engineers, I got a ton of great information on my issue and the problem I had been having as well as getting my problem solved. If you talk to them, ask them how to set up your battery bank mix. Do you put the 2 new in series together, or do you split the bank with a new and old each in their own series. I don't know if it would make a difference, but it's worth the question to an expert.

[2oldman]

time2roll wrote:
14 months and well cared for? I would combine with the new and not worry one bit.

x2

Lifelines are very good quality, and at 14 months I think you'll be fine. Make sure all 4 are FULLY charged before connecting up. You should also monitor individual voltages to ensure things are staying in balance. Both sitting and under load.

I just yanked a set 8 4-yo 12 volters from my coach, and they're all sitting at around 12.8 with very little variation.

[time2roll]

14 months and well cared for? I would combine with the new and not worry one bit.