As most of you know I'm in the process of installing LiPo batteries, inverter/charger and a stack (10) of solar panels on a boat.
Until this is up and running I'd like to run some items on 240V without running a generator.
I have 'at least' 4 12V batteries and not one of them is the same size/type/brand/age.
OK, we all know it's not advised to mix batteries........ especially in series.
What about parallel? I thought not until I read some info in a thread.
https://www.altestore.com/forums/index. ... 268.0.html
To be honest I don't place a lot of value on these batteries but they are still in 'working order' with no bad cells.
I could just run an inverter off one at a time until 'low voltage shutdown' or do what is advised on that thread.
What's your opinions?
It wouldn't be for a long period of use.
Mixing battery confusion
-
- Posts: 15965
- Joined: Fri Nov 23, 2012 3:44 pm
- Location: Mannum South Australia by the beautiful Murray River
- Has thanked: 50 times
- Been thanked: 30 times
Re: Mixing battery confusion
Are we talking a 12v system with 12v inverter? If yes, no real issues... however, isn't there always one of them
You need to load share across all the batteries evenly, that's the tricky bit. The more capacity, the less Peukert's effect will steal your capacity.
How many batteries and what capacity?

How many batteries and what capacity?
A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
-
- Site Admin
- Posts: 9304
- Joined: Thu Nov 22, 2012 7:32 pm
- Location: Mannum, SA, 5238
- Has thanked: 36 times
- Been thanked: 36 times
Re: Mixing battery confusion
OK, now you're trying me out!
One is a 100Ah AGM.
One is Similar size Calcium.
Then the two existing ones on the boat.
http://www.ozervnews.com/gallery/displa ... play_media
Guessing.......... 120 or more GEL.
100 AGM (I think)
One is a 100Ah AGM.
One is Similar size Calcium.
Then the two existing ones on the boat.
http://www.ozervnews.com/gallery/displa ... play_media
Guessing.......... 120 or more GEL.
100 AGM (I think)
*******************
BruceS
Mannum, SA
********************
BruceS
Mannum, SA
********************
-
- Posts: 15965
- Joined: Fri Nov 23, 2012 3:44 pm
- Location: Mannum South Australia by the beautiful Murray River
- Has thanked: 50 times
- Been thanked: 30 times
Re: Mixing battery confusion
So, say 4 x 100Ah batteries, mixed chemistry but it's only short term so not worth worrying about. You need to link the batteries with equal length cables from the positive to the inverter, then cables an equal length from the negative to the inverter. The positive and negative cables don't need to be the same length though, just all the ones on that side of the battery, the do need to be the same thickness though.
Now, what output is the inverter? that way we can work out min thickness for the cables required. Such a load of science required for lead acid batteries
Now, what output is the inverter? that way we can work out min thickness for the cables required. Such a load of science required for lead acid batteries

A person may fail many times, they only become a failure when they blame someone else John Burrows
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves
Those who struggle to become a leader, rarely know a clear direction forward for anyone but themselves